Nutrition, feeding and the Digestive System - Package

TABLE OF CONTENTS Are Ewe Getting Enough Water Ewe Nutrition Extending the Grazing Season Frost Seed to Renovate Pastures Feedstuffs Grass Fed Option Meeting Mineral Requirements of Sheep at Pasture Protein Content in Modern Sheep Rations Nutrition of the Ewe Flock Nutrient Requirement of Lambs Nutrient Requirement of Rams Nutrition Organic Sheep Farming Organic Sheep Production - The Facts Feeding Corn Silage Rotational Grazing The Digestive System

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Grazing June Grasses - Video Sheep Safely Graze - Video Grazing Corn - Video

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Are Ewe Getting Enough Water?

By: Jillian Craig Over the summer months it is important to provide freechoice good quality water for sheep. Sheep may drink 40 percent more water during the summer than in winter months.

Water intake can vary depending on animal and environmental conditions and the quality of the water available. Water quality can be affected by different factors such as acidity, toxic elements and compounds as well as algae growth.

Photo By: Lynn Holtrust

Water requirements change depending on the age and condition of sheep, breed differences, stage of production, size, amount of wool covering, body metabolism, feed composition and feed consumption.

Ewes carrying single lambs will have lower water requirements than ewes carrying twins or triplets.

Daily Water Requirements For Sheep Adult Sheep Lactating Ewes Feeder Lambs Baby Lambs

3.8 - 7.6 Litres 7.6 – 11.4 Litres 3.8 – 7.6 Litres 0.4 – 1.1 Litres

(1-2 Gallons) (2-3 Gallons) (1-2 Gallons) (0.1-0.3 Gallon)

In hot temperatures sheep use evaporative cooling and require more water to reduce body temperature.

Sheep that have been shorn have a higher heat load since the wool provided insulation, which is lost. In order to cope in the summer, panting will be increased and under extreme conditions, water consumption may go up as much as 78 percent.

The acidity or alkalinity of the water also plays a role in consumption. If the water has a pH value of 6.5 or lower or has pH value of 8.5 or greater, digestive upsets can occur. If the water is too acidic or basic, the flock may refuse water and reduce feed intake, which can lead to a loss of production. Lime can be added to correct the pH if the water is too acidic. If the water has a pH of 8.5 or above, alum (aluminum sulphate) can be added. Care must be taken however since alum is highly acidic.

Concentrations of elements, which reach toxic levels, can also reduce productivity. Such elements include magnesium, fluorides, iron, arsenic, mercury, lead and selenium. A water analysis could be performed to ensure maximal productivity.

Algae can be another concern for overall water consumption since it can grow in water bowls and troughs. Algae blooms occur when the water contains increased nutrient levels such as fertilizers, or when the water is warm and stagnant.

It is important to ensure that troughs or water bowls are checked daily and cleaned when necessary to reduce disease and algae growth. If using dugouts or ponds the appearance of blue-green algae needs to be monitored since it can be toxic to sheep. In order to maximize production a sufficient supply of good quality, cool, clean water should be available.

Information provided by: Greg Markwick, original source: Industry and Investment NSW and North Dakota State University, www.ag.ndsu.edu

Ewe Nutrition Ewe nutrition is one the most important aspects of production, as ewes that are fed well-balanced diets are more fertile, produce more milk and are more likely to wean a greater number of faster growing lambs. As well as producing more pounds of lambs per year, well-fed ewes are also healthier and, as a result, have a greater resistance to disease than ewes that are under nutritional stress. The nutritional requirements of a ewe, however, depend on her age and stage of production. For example, ewes in late gestation have different nutritional requirements than ewes, or ewe lambs that are lactating.

Ewe lambs have different nutritional requirements than mature ewes since they have not yet reached their adult body size at the time of first breeding. When first bred, ewe lambs should have achieved 75% of their expected mature body weight with a condition score of 3.5. If these objectives are not met, it will be difficult for the ewes to maintain condition in late pregnancy and to stimulate sufficient milk production to meet the requirements of the offspring. During pregnancy a ewe lamb will not only be supporting the growth of a fetus, but can also be expected to gain a further 10-15% of her mature body weight. Therefore, increased intakes of energy and crude protein will be required.

A ewe’s production cycle can be broken down into seven stages: maintenance, flushing, early gestation, mid gestation, late gestation, lactation and post-weaning. Management in general, and nutritional management specifically, must change for each of these production stages if a producer is to have a successful lamb crop and, more importantly, good returns for market lambs.

The nutritional requirements for ewes are least during maintenance and early gestation; and are greatest during late gestation and lactation (especially for ewes carrying multiple fetuses or nursing twins). The diagram below indicates the changes in nutrient requirements as a ewe goes through the various stages of production. During all of these stages, ewes should be provided with a good source of trace minerals (mineral block or free choice) and ample amounts of fresh water.

Figure 1. Daily TDN requirement year round of 154 pound Ewe

Maintenance The term ‘maintenance’ means that the animal is not producing heavily (i.e. reproducing, lactating, growing, etc) and, subsequently, does not have any extra energy requirements above normal body functions. The maintenance period for ewes lasts from the time the lambs are weaned to ~2-3 weeks prior to breeding (flushing period). Pasture grazing, or if in confinement, a mixture of hay and straw should be sufficient to keep ewes in good condition. The ewe’s body condition score at weaning will largely determine the amount of feed that she will need during this time. For example, animals that are over conditioned should lose some weight (an excellent opportunity to utilize low quality feeds), while those that are under-conditioned should be allowed to gain weight. Each ewe should be assessed individually at weaning and penned or pastured with ewes in similar condition. Midway through the maintenance period ewes should be condition scored again and the leanest ewes separated for preferential treatment. The goal for the producer is to have the ewes with a condition score of 3, three weeks before breeding begins.

Flushing Flushing is the practice of increasing nutrient intake and body condition during the 2-4 weeks leading up to breeding (i.e. increasing from body condition score of 3 to 3.5 when the ram is turned-out). Its purpose is to increase a ewe’s ovulation rate and therefore increase the chances of multiple births. How successful flushing is depends on the age of the ewe (mature ewes show a greater response than yearlings), its breed, body condition when flushing commences, and the stage of the breeding season. For autumn breeding, the greatest response to flushing is seen early and late in the breeding season. During mid-portion of the breeding season, when ewes are naturally most fertile, flushing less effective in increasing lambing percentage. Ewes that have not recovered from previous lactation receive the most benefit from flushing, while the practice is least effective (i.e. no response) on ewes with a fatter than normal body condition.

Flushing is generally accomplished by providing ewes with an increased plane of nutrition for 2-4 weeks prior to introducing the ram and continuing 2-4 weeks into the breeding season. This can be accomplished by providing fresh pasture, supplemental harvested forage, or by feeding ½ to 1 lb/head/day of a grain mix (oats, barley, and corn), depending on environmental stress (time of year), availability of forage, and body condition of ewes.

After breeding, the ewe flock is best maintained on good pasture, or if they are in a confinement feeding system, they should be fed enough to allow the ewes to maintain their body weight. Hay and/or silage fed ad libitum should be sufficient, however, poorer quality roughage during this period requires some supplementation with grain.

Early Gestation (15 weeks) In early pregnancy, while fetal growth is minimal, the total feed requirement of the ewe is not significantly different from the maintenance period. However, nutritional management in the first month is still important for minimizing early embryonic losses. Ideally, the target for nutritional management in the first month of pregnancy would be maintenance to a slight increase in weight.

Early in pregnancy, ewes should be fed a similar ration to ewes on maintenance rations, with a slight increase in the amount offered. The National Research Council (NRC) suggests a post flushing weight gain of 0.03 kg (0.07 lb) / day.

Mid Gestation (up to 100 days) Five weeks after breeding, the embryos are well established in the uterus, although their weights are insignificant. A live weight increase for the ewes of approximately 2 kg (4 lb.), in months two and three, equates to a 1 kg loss from the ewe's own tissues. While such a loss is tolerable, severe under-nutrition for even short periods can profoundly affect fetal development. Any degree of under-nutrition will have greater impacts on ewes that are already in poor condition.

Over-feeding during mid-pregnancy can also be detrimental. Increasing a ewe's body condition score above 3.5 at this time is wasteful, and increases feed costs. In addition, excessive abdominal fat combined with the increased uterus size can physically restrict the ewe's feed consumption in late pregnancy.

It should be noted that when weight is lost at any time during the ewe's reproductive cycle, it must ultimately be regained at a later date. In terms of total nutrient requirements it is more costly to lose and regain weight than to simply maintain it.

Late Gestation (last 4 weeks) Next to lactation, the late gestation period has the greatest nutrient demands for fetal growth, with approximately 70% of fetal growth occurring in the last six weeks of pregnancy. This is also when the ewe starts to put nutrients towards milk production. Inadequate nutrition, especially low energy levels, during this time will have detrimental effects on milk production of the ewe and the birth weight and vigour (survivability) of the lambs.

During this stage of production the plane of nutrition should be increased gradually until lambing.

Ewes should be fed good quality hay or silage and grain rations should be increase from 0.23 kg (0.5 lb) grain per day at six weeks before lambing to 0.68 kg (1.5 lb) at lambing.

Lactation (6 to 12 weeks) This stage of production is the most physiologically demanding for ewes and, therefore, nutritional requirements are at their highest. A lamb in the first four weeks of life is totally dependent upon the nutrients provided by the ewe’s milk, so optimizing milk production is critical. Body fat reserves of the ewe may contribute as much as 25-30% of the energy required to produce milk during the first month after lambing. Therefore, even with an increase in dietary energy ewes will generally lose condition during this period. Although body protein does not contribute greatly to milk production, additional protein should be added to the ration at this time, to help the ewe’s system recover from lambing. Good quality hay should be available free choice. In addition, grain should be fed at 0.7-0.9 kg (1.5 – 2.0 lb) for single lamb ewes and 0.9-1.4 kg (2.0 – 3.0 lb) for ewes supporting twins or triplets.

It is recommended that ewes nursing multiple lambs be segregated from the rest of the ewe flock, as their nutritional needs are significantly higher than ewes nursing singles. Milk production of ewes that are nursing multiple lambs peaks earlier and declines faster, and so it is also recommended that an effort be made to introduce their lambs to creep feed as soon as possible.

Providing ample amounts of fresh water is particularly important during this stage, as the ewe’s requirement will increase significantly.

Post Weaning After weaning the nutritional requirements of the ewe are no longer as critical. A maintenance ration is all that is required for the period between weaning and flushing.

Extending the Grazing Season to Reduce Feed Costs By: Jillian Craig There are many different ways to extend the grazing season. Benefits from extending the grazing season include reducing winter feed costs, improving manure distribution, decreasing fertilizer costs, reducing labour and time spent feeding, increasing soil organic matter content, yardage cost savings and improving animal performance and health. One should remember that it is very important to properly manage perennial forage so that production is optimized. In order to maximize perennial pastures rotational grazing should be practiced as well as planting productive species and keeping the soil fertility high. Proper management of perennial pastures will ensure that pastures will be productive for the full grazing season.

Stockpile grazing of Perennial Forage Stockpiling is the practice of removing sheep from one or more pastures in the summer to allow for re-growth and then grazing after the end of the growing season. Grazing the pastures or hayfields in the fall and winter is an excellent cost savings strategy for a producer. The total yearly feed cost for a forage-fed ewe is reduced by approximately 1% for each week of extending the grazing season. By stockpiling forage, there is no need to provide hay or silage during that time which saves on labour and machinery costs as well as other input costs.

Practicing stockpiling reduces manure haulage costs since the sheep spread manure naturally while grazing.

An important aspect to stockpiling pasture is the “summer resting date” this is the time when the animals are pulled off pasture or when the hay crop is removed from a hayfield. The earlier this date is, the more time the pasture or hayfield will have to re-grow which will result in higher yields and a larger carrying-capacity in the fall, which will allow the grazing season to be extended longer. However, early resting dates reduce the overall quality of the forage and later resting dates increase the quality of the forage but reduce the yield and carrying capacity. The “summer resting date” depends on whether the producer plans on grazing lambs or ewes on the forage in the fall and winter. If dry ewes are grazed in the fall and winter a producer may want a maximum yield, with an adequate quality to sustain dry ewes, which would mean an early resting date. If weaned lambs are grazing in the fall however, a producer may want to have a later resting date, which would reduce forage yield but would offer high quality forage to meet the needs of growing lambs.

Producers may choose to only take one cut of hay off in late June before resting for the fall to have an increased yield or could take one cut of hay off and graze one or two times before resting for the fall.

Depending on which stockpiling method a producer uses, early or late, different species of grasses should be taken into consideration. If a producer has an early rest period (mid-July) then a grass species with a slow re-growth is required. Bromegrass and timothy would be best utilized in an early system. If the system chosen has a late rest period (mid-August) then orchardgrass and meadow bromegrass should be considered since both species have rapid regrowth. Reed canarygrass works well with intermediate to long re-growth periods and tall fescue can work in both systems even though it has rapid re-growth. Tall fescue does hold its quality well after being frozen.

Stockpile grazing can often carry on into December or until the snow is too deep. The stockpiled forage left in the fields can also be grazed in the early spring if desired.

Annual Crops for Grazing Annual crops can be grazed as a way of extending the grazing season when perennial pasture has run out, been winterkilled or when dealing with a drought. Annual forages can be used as green feed, hay, silage and pasture.

Potential crops to use to extend the grazing season include oats and other spring cereals, winter cereals can sometimes be used depending on the situation, forage or fodder rape, turnips, sorghum-sudan grass and corn.

Spring cereals such as oats, barley and triticale can be grazed quite successfully, generally 6-8 weeks after seeding grazing can commence. Oats are preferred since they are highly palatable as compared to barley and triticale. Spring cereal mixtures may also be an option a producer may want to consider when thinking about extending the grazing season.

For fall and early-spring grazing a producer may want to consider planting winter wheat, winter triticale or fall rye. Fall rye can often be grazed seven weeks after seeding if seeded August 15 to August 31. The following spring will provide the most grazing from these winter cereals.

Forage or fodder rape can also offer potential benefits when extending the grazing season. Giant or broadleaf types of rape are upright and leafy and in general are best for pasturing sheep. Lambs may be fattened on dwarf types of rape, which are short and branched. Rape should be seeded in early July in order to be ready to graze by September through to November. Caution must be taken when pasturing since rape poisoning can occur if the plants are purple, stunted and low growing. Rape can also cause bloat in sheep. In order to prevent bloat, sheep can be fed hay to

Sheep Pastured on Forage Rape Photo By: Peter Craig

make them full before they are turned out on rape, dry feed or hay should be available to sheep when they are grazing rape to ensure they do not consume too much.

Turnips can also help to extend the grazing season for the flock. The turnip tops can be grazed once with a quick pass and then after re-growth on the second grazing allow them to eat the tops and roots. It is this second grazing that will provide the majority of the feed from the turnip crop. In order to best utilize this crop, turnips should be strip grazed. Turnips are planted in the same manner as forage rape. Rape will yield higher than turnips so the producer will have to decide which works best for their particular situation. Â Â Sorghum-sudangrass can be used as an annual forage crop for grazing sheep. Sorghumsudangrass is generally a high-yielding crop, which grows tall and can be drought tolerant.

Sorghum-sudangrass should be planted in the last week of May or early June to avoid the risk of frost. Grazing should not occur until the sudangrass is 45 cm or 18 inches tall which generally takes 60-65 days. In order to have faster re-growth, 6-8 inches of crop should be left after grazing. If rotational grazed, sorghum sudangrass will stay productive and serve as a good feed source. Caution should be taken when grazing sudangrass since it can cause prussic acid poisoning in sheep. In order to avoid prussic acid poisoning one should not graze crops that are less than 45-60 cm or 18-24 inches tall. Following a drought period, animals should not be grazed on new growth after a rain. Prussic acid occurs in immature, young plants or plants which have been exposed to frost or drought. If the field is high in nitrogen either from fertilizer or manure, nitrate poisoning may result. Nitrate poisoning can also occur if the plants undergo a drought and then rain or in a situation where the leaves are killed and the root and stem are still active such as frost, hail, drought, trampling and grazing. A producer will have to keep both prussic acid and nitrate poisoning in mind when grazing sheep on sorghum sudangrass.

Another option to consider when extending the grazing season would be grazing corn. In general, corn allows for an increased carrying capacity when grazed. It is recommended that corn be strip grazed to provide a uniform diet and offer an increase in overall gain since wastage and trampling is minimized.

Grazing Sheep on Corn Crop Residues In Ontario, the most abundant crop residue is corn stover, which can be an excellent, low cost feedstuff for dry ewes. Once the grain is harvested, the stalks, husks and leaves contain half of the feed energy, the other half being in the grain. Stover should be grazed as soon as the grain is harvested to take advantage of the higher nutrient quality. If the stover is not grazed right away, the nutrient quality will be reduced. In general, 8 to 10 ewes can be grazed per acre for one to two months.

If there is ample grain left in the field (kernels and small cobs), which passed through the combine, the stover may need to be strip grazed or ewes could be grazed only for a few hours per day to prevent the ewes from eating too much grain. Limiting access to the whole field will keep the diet uniform. In general, ewes will eat any grain first, followed by the husks and leaves and the corn stalks will be eaten last.

When grazing ewes on corn stover it is important to observe body condition regularly and if necessary, supplementation of hay may be required. When the stalks are the only item remaining, ewes should be supplemented with hay. Sheep should have access to salt, mineral and water at all times.

Wet soil conditions can cause soil compaction, which may become an issue, a producer may want to consider grazing in drier fields or waiting for the ground to freeze so soil damage does not occur. Damage to the soil in the fall can be somewhat restored naturally due to the winter freeze-thaw action. Grazing corn stover in the spring should be avoided since the following crop will be affected due to soil structure damage from the ewe’s hooves during wet conditions.

Bale Grazing Bale grazing is another option during the winter months. Bales are placed out on pastures and sheep are allowed to eat the bales. Bales can be placed around the pastures in the fall or can be placed in the fields as needed throughout the winter. Electric fence can ensure that sheep eat a few bales at a time so wastage is minimal. This can benefit a producer since bale grazing requires minimum labour and saves time. The pastures get an even amount of manure and organic matter from the wasted portion of the bales. By having the sheep out on the pastures with access to shelter, animal health is improved and housing costs are reduced.

For more information please contact Jack Kyle, OMAFRA Grazing Specialist, at jack.kyle@ontario.ca or at 705-324-5855.

Frost Seed to Renovate Pastures Printed with permission and thanks to Rory Lewandowski, Extension Educator, Athens County Ohio State University Sheep Team (Ontario Sheep News, March 2009)

Frost seeding is one method that producers can use to renovate pastures and improve pasture quality and/or the species mix within the pasture. Frost seeding involves broadcasting seed over a pasture area and letting the natural freeze/thaw cycles of late winter and early spring help to move the seed into good contact with the soil. A basic requirement for frost seeding success is to make sure that the sod cover has been opened up, that is, that there is not so much growth present that the broadcast seed will not be able to come into contact with bare soil. Generally, a pasture is prepared for frost seeding by grazing it down hard, although some light tillage or a close mowing could also be used.

Another twist to frost seeding that sheep producers can use to their advantage is to combine frost seeding with hoof action. Under this seeding scenario, let your sheep begin to graze the paddock that is to be frost seeded in early March. Let the sheep graze down the forage, scuff up the soil and open up bare areas in the sod. At this point, broadcast the forage seed across the paddock.

Keep the sheep in the paddock another couple of days and let them continue to graze and trample or hoof in the seed. This method seems to work well with sheep because they don’t trample in the seed too deep as could happen with cattle.

In general, legumes work better for frost seeding as compared to grasses. This might be because legume seeds are typically heavier than grass seed and that may help them get down to the soil level better than grass seed. The advantage to frost seeding a legume such as red or white clover is that legumes “fix� nitrogen typically in excess of their own needs. The existing grass plants use the excess nitrogen, which improves their quality as a feedstuff. Once legumes become established in a stand of pasture grass and compose 25 to 30 % of the stand, there is no need to apply supplemental nitrogen so this portion of fertilizer costs is reduced.

Red clover is probably the most widely used forage species when it comes to frost seeding. Red clover has high seedling vigor, is tolerant of a range of soil pH and fertility conditions, and tolerates drought better than white clover. Red clover produces its heaviest growth during the summer months. Red clover is known as a short-lived perennial, typically persisting in a stand for only a couple of years. Thus, many producers find themselves frost-seeding red clover every couple of years back into the same pasture. However, work is underway to improve red clover longevity and there are a couple of varieties on the market that in OSU trials have high yields and stand percentages of around 60% or greater after 4 years. This seed is higher in cost than some of the more common shorter-lived red clovers, but may be worth it to some producers in some pasture situations.

After red clover, the next most popular legume that I see being used for frost seeding is white clover. White clover is a perennial clover and begins its production in the cooler spring weather.

The older varieties of white clover are known as low growing or prostrate type of growth. This means that in order for the white clover to thrive, grass must be grazed down shorter so that light can get down to the white clover. However many seed companies now have newer, improved varieties that are more upright growing and compete better with grasses.

Other legumes that also are used for frost seeding purposes include alfalfa and birdsfoot trefoil.

Alfalfa has also been tried as a frost seeded legume with variable results. Alfalfa has higher fertility requirements than clovers or birdsfoot trefoil and it also requires a soil pH above 6.5 for best establishment results. Some producers like a combination of red clover and birdsfoot trefoil in their frost seeding mix. Birdsfoot trefoil is a persistent perennial once established, but can be slow to establish, often not showing up in a stand until the second year after frost seeding. This works well for most common varieties of red clover as they begin to decline after the second year in a stand.

Another legume that is starting to receive more interest for pasture and frost seeding use is annual lespedeza, especially in the southern third of Ohio. Annual lespedeza is a non-bloating legume that is drought tolerant. Although annual lespedeza will tolerate acidic soils (pH 5.0 to 5.5) and low phosphorous level soils, it will also respond to applications of lime, phosphorous and potassium. Applications of nitrogen will decrease lespedeza yields. Lespedeza is a warm season forage that can be used to fill in the “summer slump” period that cool season grasses experience. Expect growth of annual lespedeza to kick in during July and August. Do not graze after early September to allow sufficient seed production for stand regeneration. I know of one beef producer in Athens County who frost seeded lespedeza into his pasture several years ago and he was very pleased with its performance during the summer’s drought. However, I did some frost seeding trials with lespedeza on 4 different farms a few years ago and didn’t have much success. My experience was that the seed was light, more similar to a grass seed, and I don’t think good seed to soil contact was established, even though the pastures had been grazed down tight and there were areas of soil showing. This might be the case where the seed should be broadcast and then let animals continue to graze for a couple days to use some hoof action to get better seed to soil contact.

As a final note, remember that when seeding a legume that has not been grown in the pasture for a number of years, it is a good idea to include the proper bacterial inoculum with the seed to insure that the bacteria responsible for fixing nitrogen becomes associated with the plant roots.

Grasses do not generally work as well as legumes to establish through frost seeding, although in some of those pasture fields that have been trampled and beat down, the possibility for success should be greater than in conditions of a thicker sod. Frost seeding trials have indicated that perennial and annual ryegrass is probably the best choice for frost seeding followed by orchardgrass. My preference, given the increased seed prices we have seen in the past couple of years, would be to stay away from frost seeding grass seed and use a no-till drill as the preferred seeding method.

Once the decision has been made to frost seed and the forage species selected, the producer must think about timing and seeding rate. Generally, from mid-February through the end of March is a good time to frost seed. Of course, if there is a good snow cover on a hillside that you desire to frost seed, you may want to wait until the snow has melted or your seed may all end up being carried down the hill. Recommended frost seeding rates by species is included in the following table: Forage Species

Seedling Rate (lbs/acre)

Red Clover

4-8

Ladino/White Clover

2-3

Alsike Clover

2-4

Birdsfoot Trefoil

4-6

Annual Lespedeza

15 - 20

Ryegrass

10 - 15

Orchardgrass

4-6

Researchers have played around with frost seeding rates and found that by doubling these rates plants per square foot can be increased in the stand; however, the number of plants established as a percentage of the seeding rate was actually slightly lower than what resulted from these recommended rates. For the average producer, these rates are probably the most economical, but there may be situations that warrant higher seeding rates. For example, where the existing grass sod has not been grazed down or opened up, higher frost seeding rates may be necessary to insure that at least some of the seed makes it down to soil level.

Frost seeding is a low-cost seeding method that can allow the sheep producer to renovate pastures by increasing the legume content of the pasture and moving some improved genetics into the pasture mix. The end result can be a more productive, higher yielding pasture that requires less synthetic nitrogen inputs.

Feedstuffs Sheep can utilize a wide variety of feedstuffs. Feeds are classified into groups based on their nutrient content and physical form. Most common feeds can be placed in one of the following groups: Roughages (forages): (Note: Most mature sheep will require ~4-5 lbs of hay/day through the winter) Grass forages (hay or pasture) • high in fibre (cellulose) and usually low to intermediate in energy • protein content varies, depending on the plant species and stage of maturity, typical range in crude protein could be as varied as 5 to 12% (i.e. grass are highest in protein and lowest in fibre early in the growth period, as the stem matures and after ‘setting seed’ the protein level will drop significantly) • examples are timothy, crested wheat, fescues, etc.

Legume forages (hay or pasture) • fibre dependent on stage of growth and leave content (e.g. mature alfalfa has a high stem to leaf ratio) • protein content is higher than grass forages, generally above 16-20% (legumes are able to fix nitrogen in the soil) • because of particular proteins in legumes, caution should be taken when first feeding legume forages (i.e switching from grass hay, or turning onto pasture in the spring) to prevent frothy bloat.

• Examples are alfalfa, clovers, etc.

Silage • silage is produced when green forage is preserved using fermentation (acidification in the absence of oxygen) • the major advantage of silage is that the crop can be harvested when it is ready in almost all weather conditions (hay must be dried to ~90% dry matter before baling to prevent spoilage, whereas silage is stored with a dry matter content of 40-60%).

• when exposed to oxygen, silage may spoil. Improperly stored silage may cause problems such as listeriosis in sheep • ensiling is not restricted to grasses and legumes; silage can be made from a wide range of crops including corn, barley etc • compared to hay, harvesting, storing, and feeding silage can require a greater capital investment in equipment and facilities.

Green Feed • forage is not dried thoroughly before baling • may be used as a means of making use of a poor harvest or if conditions are poor during haying • mildew and moulds can be a problem Concentrates (grains and commercially mixed rations) • high in energy and relatively low in fibre • fibre level depends on processing of the grain; grains that are pelleted or crushed will have a much lower fibre content than whole grains with the hull included (some studies indicate that lamb performance is better and there are fewer digestive upsets with whole grains)

• •

most have a moderate protein content (~12% crude protein) examples are corn, barley, oats, commercial mixes

Protein Supplements • high in protein, usually high in energy • variable fibre content • examples are oilseeds (soybeans, canola meal) Mineral Supplements • may be included in a commercially mixed ration or supplied by free choice access to mineral blocks or loose mineral • do NOT purchase cattle mineral supplements, as the copper is often too high for sheep

Ration Formulation The goal of ration formulation is to prepare a feeding program which meets the animal’s nutrient requirements, is properly balanced, palatable, promotes or discourages intake (depending on the purpose of the ration), is suitable for a given management situation and is reasonably priced. To this end, there are a number of questions that need to be asked: • • • •

What type, age, weight of sheep is being fed?

What is desired production level and rate of gain?

What feeds are available for use for the formulation?

Are these feeds home-grown or are they purchased?

Most Feed Companies offer a Sheep Ration Formulation Service.

A list of the energy and protein content of some common feeds is contained in Table 1. Remember that although these figures will give you a good idea of nutrients in different feeds, you must have you feed analysis for accurate values.

Table1. Energy and Protein Content of Some Common Ontario Feeds*

1st cut legume hay 1st cut grass hay 1st cut mixed hay 2nd cut legume hay

86.7 87.7 87.7 86.8

% Crude Protein (dry matter basis) 15.8 9.7 12.2 17.7

legume hay silage

46.9

17.6

59

grass hay silage mixed hay silage corn silage oats barley mixed grain grain corn soybean meal 44%

38.8 49.4 36.5 88.5 88.6 88.4 86.6 89.0

13.0 15.8 8.0 12.1 12.2 12.3 9.6 47.8

57 58 66 74 82 77 90 81

Feed

% Dry Matter

% Estimated TDN (dry matter basis) 58 55 56 59

*Source: OMAFRA Feed Advisory Program (table taken from OMAFRA Factsheet Basic Beef Cattle Nutrition)

Meeting Sheep Mineral Requirements at Pasture Christoph Wand – Beef Cattle and Sheep Nutritionist, OMAFRA (Ontario Sheep News, June 2010) GETTING MINERALS INTO SHEEP For a starting point, all sheep in Ontario need some selenium supplementation as this Province’s soils are selenium (Se) deficient. We need a selenium source, so ‘no supplement’ is not an option! Often people struggle with whether or not the requirements of the sheep are being met. Now assuming an appropriate pasture mineral supplement product is being used, the only way to determine if the intake is according to specifications is to read the label of the product as to what intake should be attained per head per day on any product! That said, 15 to 25 g per head per day is pretty typical intake recommendation for a commercial mineral premix (‘free choice mineral’), and in turn, a 25 kg bag of mineral premix should last 1000 to 1660 ewe-days per bag. This calculation must also be done for trace-mineralized (TM) salt when used, but will certainly result in approximately double the number of ewe-days per 25 kg product compared to premix. Since Se deficiency is a big deal in Ontario, look for a sheep mineral that provides it at the highest levels possible; any higher you’d need a vet script which some farms may. But this is a result of Federal rules that need to be relevant in high selenium provinces too. If you are considering a TM salt product on pasture, look for TM salt that is 120 mg/kg selenium or formulated for higher intake.

There are a few add-ons you may consider with mineral premix or TM salt such as adding a coccidiostat for cocci control in lambs.

WHAT ARE MINERAL SUPPEMENTATION REQUIREMENTS The key to determining what level your animals need to be supplemented at is a forage test. Table 1 illustrates the minimum levels of various minerals this author would recommend in sheep forages (fresh perennial forages). The upper section contains standard minerals reported on, the next two are optional, and then trace minerals which cannot easily be tested for, so should be assumed as deficient. These values are based on requirements for critical stages such as late pregnancy/lactation for ewe lambs, and then extrapolated to ewes. It is a ‘worst case scenario’ for the ewe flock for each of the mineral parameters, as those ewe-lamb requirements are higher than for ewes at any stage of production. Similarly, the same has been done for a growing lamb.

Dr. Kendall Swanson, a researcher at the University of Guelph comments that “typical average to good quality pastures in Ontario may not need supplementation of most minerals and vitamins, but there likely are some quite low quality pastures that do.” How do you know where your pastures fit in? Feed analysis compared to requirements is the only way to tell! A farm should build an inventory of forage tests over time to account for seasonal and weather variations on mineral uptake by the pasture. If, over time, the forage test is above the levels in Table 1, then no further action is needed on that nutrient.

In looking at this information many people farming on high fertility soils will realize there is no need to routinely supplement calcium, phosphorus, potassium, and perhaps other minerals. High phosphorus (P) minerals (1:1 and even 2:1 Ca:P ratio) are typically over-supplementing P levels, because of the high manure or fertilizer levels in parts of

the province that have been farmed for several decades. The only way to be sure is a forage test for minerals! All sheep in Ontario need Se, and if that can be done with a TM salt, then perhaps that is all a given farm needs. Some flocks on very low P soils may need a source of that macro-mineral, which is absent in TM salt.

BOTTOM LINE ON MINERALS AT PASTURE The only way to really tell what you need is a forage test, and to accept Ontario is selenium (Se) deficient. Once you have done these two things you can figure out whether you really need a complete premix or a trace-mineralize (TM) salt to meet the mineral needs of your sheep at pasture. And remember, at pasture all of the vitamins A, D, and E sheep could ever need are there for free. Get it while you can!

Table 1. Minimum requirements for macro and micro-mineral for mature ewes and growing lambs on pasture assuming highest level of requirement within that class, as adapted by Christoph Wand from Nutrient Requirements of Small Ruminants, 2007. Calcium, phosphorus, manganese and molybdenum recommendations still stem in part from Nutrient Requirements of Sheep, 1985 and other sources for economy, safety and clarity reasons.

Unit of Nutrient Mature Lambs Measure* Standard on forage test Calcium (Ca) % 0.30 0.35 Phosphorus (P) % 0.25 0.30 Potassium (K) % 0.50 Magnesium (Mg) % 0.11 Sodium (Na) % 0.06 Sulphur (S) % 0.16 ppm or Zinc (Zn) 36 mg/kg ppm or Manganese (Mn) 20-40 mg/kg Optional on forage test ppm or Copper (Cu) 6 (maximum 15) mg/kg ppm or Molybdenum (Mo) 0.5 mg/kg Not likely on forage test – separate analysis ppm or Cobalt 0.17 mg/kg ppm or Iodine (I) 0.65 mg/kg ppm or Iron (Fe) 30 75 mg/kg ppm or Selenium (Se) 0.3 mg/kg * in total ration or as reported on forage test assuming 100% pasture intake. Ppm or mg/kg are the same unit of measure, both measuring number of units per million units. ** Supplementation ingredient for single mineral, if required

The Grass Fed Option

By Shannon Meadows

H

ere at OSMA, we have had a number of inquiries from producers looking for information about grass fed Ontario Lamb, so in response we wanted to gather some information on the advantages and disadvantages. This topic is not unfamiliar to Ontario producers, and OSMA has been a founding sponsor for the two Functional Foods Conferences in 2006 and 2009, which highlighted opportunities for producers from both a nutritional viewpoint and a consumer preference perspective. The purist standard for being branded as grassfed state that grass and/or forage shall be the feed source consumed for the lifetime of the ruminant animal, with the exception of milk consumed prior to weaning. The diet shall be derived solely from forage, and animals cannot be fed grain or grain by-products and must have continuous access to pasture during the growing season. This definition does have some variance depending on what organization puts forward the certification standards.

As with all production and management systems, there are trade-offs to raising lamb primarily on grass or confining them and feeding them a grain ration. A producer must choose the appropriate feeding and management system for their lambs based on their individual preferences, available resources, and market demand.

One of the first potential advantages to a grass fed system is that the grass-based diet is natural to the physiology of the sheep, and the lambs are less likely to suffer digestive upsets or other metabolic disorders like enterotoxemia (overeating disease) and urinary calculi. Also, grass-fed lambs are usually weaned later than their grain-fed counterparts, thereby reducing the risk of mastitis in their dams.

Another potential advantage is the presence of a specialized health based market for grass fed lamb. Meat and milk from grass-fed ruminants contains more conjugated linoleic acid (CLA), vitamin E, omega-3 fatty acids, beta-carotene, and vitamin A than the meat and milk from grain-fed animals. The linoleic acid content of grasses varies by plant species and maturity, being highest in grasses that are in a growing, vegetative state. CLA is readily absorbed by the animal from the rumen and ends up in milk, meat, and fat. Therefore, the improved nutritional profile of grass-fed meat and milk may enable some producers to command a premium price for their products if they market directly to consumers, restaurants, and specialty food stores/ chains.

Also, pasture gains can offer an economical advantage 22

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compared to those achieved on feeding grains, however, this is dependent on land costs, and also the production challenges that you might face with this management system.

Like all things, there is a balance, and raising grass fed lamb does come with some disadvantages. There are more external variables to manage on pasture than in confinement.

Internal parasites are one of those variables, and are a much larger problem with grazing animals than those being fed in confinement. So you may require frequent de-worming or handling to monitor parasite levels. Controlling parasites in grazing sheep is becoming an even greater challenge due to the widespread emergence of drug-resistant worms. While grazing animals are less likely to experience metabolic disorders, grazing poses its own set of health risks such as bloat and grass tetany. However, with good management practices these risks can be minimized.

It is important to recognise that utilizing different production systems means that you will be selling a different product, so along with the differences in production, there are also carcass differences. Grain feeding tends to improve rate of gain, and usually bring a higher price at auctions because they tend to carry a higher degree of body condition. The taste is also different, and although grain-fed lamb has generally been preferred in taste panel tests in Canada, this does vary greatly among different consumer markets.

Also, since raising Ontario lamb on pasture is seasonal, there is a challenge to provide a steady supply of lamb throughout the year. This seasonality is a hindrance to being incorporated into large grocery store markets or consumer branded labels.

Currently, a value chain promoting grass fed lamb in live auction markets has not been developed. Therefore many producers feel as though direct marketing or farm gate sales are the most advantageous methods of marketing grass fed lamb.

Lastly, but certainly not to be overlooked, is the increased predation challenges when operating a grass based system.

In Ontario, producers are continuing to suffer monumental predation losses, with the main culprit being coyotes. So, if you do choose to operate a grass fed system, a very thorough predation management system will need to be in place.

Whether you choose to raise grass fed lamb, grain fed lamb or a combination of both, what it really comes down to is understanding what system fits your management style, facilities, and what you like to spend your time doing.

For more information please contact Jack Kyle, OMAFRA Grazing Specialist, at jack.kyle@ontario.ca or at 705-324-5855. OSN

Nutrient Requirements of Lambs Colostrum It is important that lambs on receive at least 170 ml (6 oz) of fresh or frozen colostrum as soon as possible after birth. Lambs that do not receive colostrum will generally die. Colostrum is yellow and thick in appearance compared to milk that is produced later during lactation. Ewes will have a limited amount of colostrum that will gradually be depleted by the lambs during the first day after birth.

Colostrum may be saved and frozen for up to a year for emergencies. Colostrum contains antibodies from the ewe, which will help protect the newborns from various diseases. Colostrum is also higher in energy than milk. As lambs are born with few body reserves, it is essential that they need energy soon after birth.

Feeding lambs on milk replacer Orphan lambs or lambs that have been removed from ewes with multiple births (e.g. triplets), will either have to be fostered onto other ewes or raised on milk replacer. Lambs less than four weeks of age that are being bottle fed, require a replacer that is high in milk fat and good quality protein. Since lambs at this age are essentially non-ruminants, it is the quality of protein, not the quantity that is important.

Remember that the lamb actually has to suckle to prevent the milk from entering the rumen. Therefore, ensure that the nipple opening on the bottle is small enough to force the lamb to suck, otherwise the lamb will not be able to digest the milk properly and will become bloated Pre-weaning During the first weeks of life, lamb growth and development is dependent upon the ewe’s milk production.

Lambs not receiving adequate milk during the first month of life are more prone to contracting infectious diseases and will show a poor overall growth performance. Although they will start nibbling on feeds within a few days of birth, lambs less than four weeks of age are non-ruminants; and will consume high levels of milk and very little in terms of dry matter. Although feed intake is minimal during these first weeks, it is important to introduce creep feed to the lambs at roughly 10 days of age. If using a commercial creep feed, it is best to begin with an 18% crude protein ration.

Having lambs adapted to eating creep feed will greatly lessen the stress of weaning. Always offer the creep free choice to the lambs, but devise a means of preventing ewes access to the ration (creep feeder). It is also advisable to Lambs at a creep feeder provide lambs with good quality hay that is leafy and tender. Lambs can compensate for inadequate milk supply to some extent by increasing consumption of solid feed. However, they cannot consume significant amounts of feed during the first two to three weeks of life. As lambs consume more dry feed their digestive systems develop further so they are better able to digest and utilize dry feed. Once lambs are consuming at least ½ pound per day of dry feed weaning can be considered. Weaning usually occurs anywhere from 8 to 20 weeks of age, depending on the type of reproductive management system (e.g. once per year spring lambing operations will generally weaning as animals come off pasture, whereas those with accelerated lambing need to rebreed sooner).

Weaning Weaning can be a stressful time for the lambs and may lead to a decrease in feed intake. To minimize stress it is recommended that the lambs are left in the same pens and that the ewes be removed so that they are out of sight and hearing range. Continue to feed the lambs the same creep ration. Any changes in the ration should be done gradually and over several days.

Post-weaning (feeder lambs) Dry matter intake for feeder lambs varies between 3.5% and 4% of their body weight. Actual intake, however, depends on several factors, including.

• Age • Size and condition • Growth rate • Amount of feed offered • Competition for available feed • Palatability • Physical form of feed (long, chopped, rolled, pelleted, etc.)

• Energy and fibre content of feed • Ambient temperature and humidity • Availability and quality of water Lambs may be marketed at weaning (new crop lambs), as light weaned lambs or as heavy finished lambs (>95lbs). Your marketing strategy will determine how quickly you will want the lambs to grow (rate of gain) and how soon they will finish. For some producers the answer is easy, the lambs are left on pasture until the fall and marketed straight from the field. Rate of gain in these lambs will be slow, but the fed costs will be minimal. Many producers supplement a forage diet with concentrates to improve the rate of gain. In some cases, concentrates will total 50% of the ration. If you are pushing lambs for very fast growth, know the signs of rumen acidosis, and take precautions when making feed changes. Table 2 shows examples of diets for two rates of gains.

The nutrient requirements for lambs will not only be influenced by the desired rate of gain, but also by the weaning weight of the lambs, their sex and their breed. In terms of weight, lambs weaned at 11 – 16 kg (25-35 lbs) tend to gain at an accelerating rate with increased weight. At a practical level, this means it is much more efficient to feed a pound of grain to a two-month-old lamb than to a six-month-old lamb.

Ewe lambs have lower voluntary feed intakes than either ram lambs or wethers and tend to deposit more fat than males. As a result they grow slower and are less efficient converters of feed to live weight gain.

Marked variability has been seen in the growth rates between breeds. The differences are partially due to differences in feed consumption and efficiencies in feed utilization for fat and lean deposition. Breeds also vary in their mature weights. Breeds with low adult weights will mature at a lighter body weight than large breeds. Therefore, light breeds will tend to fatten (finish) at lighter weights.

Table 2: Feeder lambs rations (Please note: the following are examples only – contact your OMAFRA specialist or consult with a nutrition company representative to develop balanced, cost effective rations for you farm) Average Daily Gain Lamb Weight 0.9 lbs gain/day 0.6 lbs gain/day Barley grain (1.6 lb) 66 lbs Barley grain (2.4 lb) Canola meal (0.4 lb) Canola meal (0.2 lb) Grass hay (1.7 lb) Alfalfa hay (1.0 lb) Limestone (0.02) Limestone (0.02 lb) 88 lbs Barely grain (2.8 lb) Barley grain (3.0 lb) 32 % protein supplement (0.4 lb) Alfalfa hay (1.0 lb) Alfalfa hay (0.6 lb) Limestone (0.02)

Growing Replacement Ewe Lambs Once replacement ewes have been selected from the lamb crop, they should be fed a high quality forage-based ration. The end goal is to have them at 75% of the mature body weight, with a body condition score of 3.5 at the time of their first mating. Although the diet must be sufficient to allow for optimal growth, it is not advisable to feed ewe lambs on high-energy rations. Very fast growth may decrease longevity and there are indications that high body fat during development may decrease milking ability later in life.

Nutrient Requirements of Rams Similar to feeding replacement ewes, the breeding target for ram lambs is 75% of mature weight at a condition score of 3.5 to 4. Once rams are allowed to run with the ewes, they spend very little of their time actually eating. This can result in a weight loss of up to 12% of their body weight during a 45 day breeding period. In many cases, forage alone is not adequate nutrition for placing rams in proper body condition for the breeding season. At the very least, rams should be evaluated for body condition six weeks before breeding. Thin rams should receive grain supplementation as a means to increase body weight and condition. Mature rams can be maintained on pasture or wintered on good quality hay. Six Photo By: Marlene Raymond to 8 pounds of mixed grass and clover hay is sufficient to meet the daily energy requirements of a 250-pound ram.

All rams should have fresh, clean water available at all times, as well as salt and minerals.

Nutrition Reprinted in part from ‘Nutrition Guide for BC Sheep Producers’ Written by Dr. Steve Mason and published by the Province of British Columbia.

(Modified by OSMA, 2010)

Introduction Feed costs account for approximately 80% of the expenses for an average Ontario farm.

Therefore, it is imperative that producers evaluate and manage their feed resources to maximize farm profit and flock productivity. To this end, producers should work with extension personnel and nutritionists to build a solid nutritional program that includes feed analysis and ration formulation to meet the needs of the flock.

Feed Analysis It is difficult to assess feed quality without performing a detailed chemical analysis to determine the quantity of nutrients present. A basic feed analysis will provide the producer with information on the dry matter (DM), fibre (neutral detergent fibre and acid detergent fibre), total digestible nutrients (TDN), protein, vitamin and mineral content of the feed. Knowing the level of nutrients that are available in a given feed allows for the formulation of rations that meet the nutritional requirements of animals in a given stage of production.

Water It should be noted, however, that while formulating diets to meet the production needs of the flock is important in order to maximize productivity; all the planning and formulating can go to waste if water is not adequately supplied. It is essential that a fresh source of water be available to the flock at all times.

This is particularly important for lactating ewes that require a large amount of water to produce adequate amounts of milk - and young lambs. It is recommended that one square foot of water surface be provided for every 40 ewes.

Dry Matter (DM) Dry matter analysis actually measures the amount of moisture in the feed and is widely variable depending on the feed source. Hay and grain usually contain roughly 10% moisture, silage can contain anywhere from 50-75% and pasture plants are often 80-85% moisture. DM content is an important measurement, as it affects animal intake. For example, a ewe is that is capable of consuming 2 kg (4.4 lb) of leafy grass hay (10% moisture; 90% DM) can also consume 9 kg (19.8 lb) of leafy grass pasture (80% moisture; 20% DM). In both cases 1.8 kg (4 lb) of DM will be consumed. Therefore, expressing feed analysis, animal intake and nutrient requirement on a DM basis eliminates moisture as a variable in the comparison of different feeds and in the calculation of balanced rations.

Fibre The fibre content of feed is expressed as Neutral Detergent Fibre (NDF) and Acid Detergent Fibre (ADF). NDF is a chemical estimate of the plant cell wall. The plant cell wall is composed largely of difficult to digest cellulose, whereas the inside of the cell contains much more soluble carbohydrates (e.g. starch). Although the animal can make use of both cellulose and soluble carbohydrates, cellulose is a more complex carbohydrate and takes longer to break down. Various types of plants will vary in proportion of cell wall versus cell contents, and generally as a plant matures the percentage of wall content will increase. A high NDF indicates that the feed has a large percentage of cell wall material. As NDF increases the animal’s intake will decrease. This is because the more fibrous the feed, the bulkier it

is and the sooner the rumen will reach capacity. Very fibrous feed will also take longer to break down and be passed from the rumen. Therefore, feed intake will be restricted by the size of the rumen. If only very fibrous feeds (high NDF) are fed, the animal may not be able to eat enough to maintain production.

ADF is a measure of the digestibility of the feed (i.e. how much of the feed can actually be used by the animal). ADF values are used to calculate other measures of energy content such as total digestible nutrients.

Total Digestible Nutrients (TDN) TDN is a measure of the energy content of the feed and is reported as a percentage. How much energy an animal requires in their diet will depend on their age, sex and stage of production. The energy content can also be expressed as digestible energy (DE), which is measured in megacalories per kg (Mcal/kg). Energy is the nutrient that is most often below the level required for production (limiting nutrient) and energy usually accounts for the largest portion of feed costs. Most energy in sheep diets comes from the cellulose and hemicellulose in forage and the starches in grain. Fats and oil are very high in energy, but are not often used in sheep diets.

Protein It is the quantity and not necessarily the quality of protein that is important in sheep rations. Proteins vary in how easily they can be broken down in the rumen, from being completely insoluble to 100% soluble. Most types of proteins fed to sheep are relatively soluble, meaning that the rumen bacteria can digest them. During bacterial digestion the nitrogen in the protein is released and used to maintain growth and reproduction of the microbe population. Microbes are constantly being passed out of the rumen into the abomasum and intestine, where they are broken down by the sheep’s digestive enzymes. Once they are digested they are absorbed and utilized by the animal as a protein source. Therefore, the quality of protein fed to sheep can vary, but the quality of the microbial cell protein is consistent. Hence, relatively low quality (low cost) proteins can at times be used to supplement sheep rations. This includes nonprotein nitrogen (NPN) sources, such as urea, which provide nitrogen to the rumen microbes, without having to be first broken down from a more complex true protein. In order for rumen microbes to utilize NPN, however, sufficient soluble carbohydrates (e.g. starch) must included in the diet. If there isn’t enough energy or if the NPN is fed in excess of the microbes ability to use it, the animal may suffer from toxicity. NPN use as a protein source should be restricted to maintenance diets, as it will generally not meet the protein requirements for late gestation, lactation, or lamb growth.

Protein that is not soluble in the rumen passes intact to the lower digestive tract, where it will be digested and absorbed. This type of protein is called ‘bypass protein’ as it bypasses the rumen bacteria.

Bypass protein is efficiently utilized and is a means of providing protein directly to the animal, rather than indirectly through the microbes. Bypass proteins tend to be higher quality and generally more expensive.

Feeding a very high percentage of bypass protein and little soluble protein, however, is not advisable as it would result in poor microbe performance.

Minerals Calcium (Ca), phosphorus (P), potassium (K), magnesium (Mg), salt (NaCl), cobalt (Co), iodine (I), copper (Cu), and selenium (Se) are the minerals most commonly analysed and are reported as percentages or parts per hundred (Ca, P, K, Mg, NaCl), parts per million (Co) or parts per billion (Se).

Calcium and phosphorous are expressed on feed tags as a ratio (Ca:P). Sheep can handle a Ca:P ratio anywhere from 1:1 to 7:1 as long as the minimum requirements of available calcium and phosphorous are being met. It is important that the Ca level is at least as high as the P in the diet. This is necessary as P interferes with the absorption of Ca, creating a deficiency in the animal even if the actual level in the diet is adequate. This is particularly important in growing animals and lactating ewes. Most grass and legume hays contain an adequate level of Ca while grains tend to have relatively high P levels. Ca and P are required for the maintenance of bone structure and proper muscle and nerve function. Signs of

deficiency include abnormal bone development (rickets), knock knees, slow growth, “runtiness”, listlessness, depraved appetite (chewing on rocks, wood and bone) and “downer ewes”. Ewes in late pregnancy should not be fed very high levels of dietary Ca (e.g. only alfalfa hay), as this may interfere with the release of body reserves of Ca required at the onset of lactation causing hypocalcaemia.

Magnesium is closely associated with the metabolism of Ca and P and is required for proper nervous system function. Normally feeds contain adequate levels of magnesium, however, deficiency can cause grass tetany.

Cobalt is an essential trace mineral that is needed in order for vitamin B2 to be manufactured by the rumen microbes. A deficiency in cobalt may cause sheep to become thin, unthrifty and anaemic. Co is often included in salt (blue salt block) Iodine, another trace mineral, is required by the thyroid gland for regulation of food utilization.

Deficiency in iodine can cause goiter, which is commonly seen in newborn lambs born to iodine deficient ewes. Goiter can be recognized in young lambs by abnormal swelling under the throat due to an enlarged thyroid gland, abnormal wool coat at birth, still births and neonatal mortality (also frequently added to salt blocks).

Copper is widely distributed in natural feedstuffs and deficiency is rare as the recommended daily intake is low (8-15 mg/kg DM). However, copper poisoning and toxicity are common. For this reason it is not advisable to feed mineral supplements for other livestock to sheep, as the tolerance for copper is generally higher in other species. Under normal conditions, the copper supplied in feed is adequate for sheep, however, high levels of molybdenum, iron and zinc can interfere with copper uptake.

Selenium is important because of its role, along with vitamin E, in the prevention of nutritional muscular dystrophy (white muscle disease). The minimum requirement of selenium for sheep is 100 parts per billion, and when fed to ewes at this level it will prevent white muscle disease in young lambs.

Vitamins Vitamins can be broken down into two main groups: fat-soluble and water-soluble. Fat -soluble vitamins include vitamins A, D, E, and K, which can be stored in the liver and body fat during periods of abundant supply and rationed out from these organs when supplies become scant. Water-soluble vitamins, which cannot be stored for future use, include B-complex vitamins and vitamin C. B-complex vitamins are manufactured by rumen bacteria in adequate amounts on a daily basis, provided the animals are supplied with enough energy, protein and minerals to enable the bacteria to do so. Vitamin C is manufactured in the animals’ tissue.

Vitamin A is not synthesized by ruminants and, therefore, needs to be supplemented in the diet. It is essential for sight and the maintenance of tissues (the lining of the digestive tract and the reproductive tract), lungs, eyes and skin. Vitamin A is provided through green forages. However, it is lost as stored hay ages. Therefore, vitamin A supplementation may be needed if you are feeding hay older than ~4-5 months.

Organic Sheep Production – The Facts

By Kate Belbeck, Organic Farm Inspector The term “organic” is becoming more mainstream with respect to food production, but what does organic really mean in sheep production? The answer to that question is ultimately certification. To run a truly organic sheep operation, one needs to be inspected, monitored and certified on an annual basis at minimum by an independent, unbiased certification body. Depending on each producers’ marketing arrangement, there are various Organic Standards to which one can be certified, each with their own set of slightly different rules and regulations depending on the country, and sometimes even the province, in which the organic products are to be sold.

Organic sheep production involves much more than just raising sheep and lambs without antibiotics or hormones. There are specific standards pertaining to all areas of production including the origins of the livestock, feeding, breeding, healthcare, living conditions, pest management and processing.

Flock Origin - The key starting point with organic sheep production is the flock origin.

In particular, one has to take into account the suitability of the particular breed to the environment. However, even more important, is the selection of breeds or lines that show resistance to disease and parasite infestation. Quite often, these breeds are less common and may be harder to obtain.

Preferably, to start in organic sheep production, one should purchase animals from certified organic sources. However, when this is not possible, you can purchase non-bred ewe lambs and rams and transition them into the organic system. The meat from these starting animals cannot be sold as organic, however, once they are raised in the organic system for a period of one year, they may be sold as certified organic breeding stock.

The offspring from these animals can also be sold as organic, both as breeding stock or meat, provided that their dam was raised under the organic standards from the beginning of the last third of the gestation period, or around 95 days of gestation.

Feeding - Organic sheep production requires that all animals be fed a ration suitable to the condition of the animal and the stage of development. This includes the lambs’ need for natural milk, and the sheep’s need for a substantial proportion of roughage in the diet, either by pasture grazing, hay or silage. In the event that silage is fed, hay must also be provided.

In addition, sheep rations must not contain medications or veterinary drugs including prophylactic antibiotics (growth promotants), mammalian or avian slaughter by-products, synthetic preservation or colouring agents, or synthetic appetite-enhancers or flavourenhancers.

Above all, all feedstuffs, whether grain or forages, fed to organically raised sheep must be of a certified organic origin. For many producers that grow their own hay or grain, this could mean a 3-year transition period to turn a conventionally grown crop to an organic status. Vacant land that has had any type of chemical treatment such as weed sprays or fertilizers also need to undergo a transitional period.

Breeding - For sheep producers, the breeding standards in organic production are fairly easy to comply with. Organic production favours natural breeding, though artificial insemination is permitted. Embryo transfer is also permitted providing that is does not involve genetic engineering. Conversely, reproductive hormones used to trigger or synchronize estrus are not permitted.

Healthcare - There are many extensive regulations surrounding healthcare in organic livestock production. Essentially, it is the producers’ responsibility to minimize the need for antibiotic or parasite treatments. This includes selecting appropriate breeds or strains of animals, supplying feed rations sufficient to meet the nutritional requirements of the animal, establishment of appropriate housing, pasture conditions, space allowances and sanitation practices, and minimizing stress.

Surgical procedures such as tail docking and castration are permitted if they are necessary to improve the health, welfare or hygiene of the animals providing they are performed at the youngest age possible.

Under the organic standards, it is required that animals showing detectable disease, lesions, lameness or injury receive prompt treatment. Treatment should never be withheld to preserve the animal’s organic status. These animals will then have to be marketed separately, as non-organic.

It is important to note that in particular situations, vaccinations, parasiticides and other treatments are permitted, if approval is granted by the certification body prior to their use.

The approvals are primarily given if these conditions are not manageable without treatment and pose a welfare risk to the livestock.

Living Conditions - The housing provided to sheep raised in an organic system must accommodate health and natural behavior. This includes access to the outdoors, shade, shelter, rotational pasture, fresh air and natural daylight. Sheep housing must also have appropriate resting and bedding areas, including non-slip floors that must not be fully slatted.

The space requirements for organically raised sheep are as follows: • Indoor space – 1.5m2 per head plus 0.35m2 for each additional lamb • Outdoor space – 2.5m2 per head plus 0.5m2 for each additional lamb

Pest Management - External pests, such as flies or rodents, should be managed first by preventative measures, ie. Removing the source of attraction. Secondarily, mechanical,

physical and biological methods can be used. Chemical pest management such as fly sprays or chemical rodent poisons are generally not permitted.

Processing - The steps involved to being a successfully certified sheep operation are extensive and it is extremely unfortunate that one of the most difficult regulations for sheep producers in Ontario to follow is the processing regulation. In order for a producer to sell lamb (meat) as “certified organic”, it must be processed in a certified organic processing facility. At present, there is only one such facility in Ontario, located in Zurich. Until there are more avenues for organic producers in Ontario to have their lamb processed, it can only be marketed as “Certified Organically Grown” as opposed to truly “Certified Organic”. However, despite this current situation, is it not a wasted effort to raise sheep organically.

Overall, there is no simple answer to the question “What is organic?” when it comes to sheep production. There are far too many extensive regulations to cover in such a publication, and these regulations are very much dependent on the situation of each individual producer and their goals for their sheep operation. Products being sold in Ontario, in Quebec or in the United States have different regulations though the same general principles apply. Of the utmost importance though is certification. Certification is the assurance to the industry and the consumer that you are producing what you claim to be, in an appropriate and acceptable manner. Ultimately, if it’s not certified, it’s not organic.

For more information on the certification process and standards in Ontario, contact Pro-Cert Organic Systems Ltd. at 705-374-5602 or go to www.pro-cert.org.

Rotational Grazing What is rotational grazing? As I talk to people across the province about grazing management I have come to realize that rotational grazing means different things to different people. The dictionary definition of rotation is to change or alternate in a particular sequence; regular variation. To a crop producer, rotation means a different crop or sequence of crops in a field over a number of years. When we talk about rotation in relation to grazing, the most important factor is the state of the grass growth, and the rotation refers to the movement of the livestock from one paddock to another during the grazing season. The guiding principals of rotational grazing are to give the grass crop every opportunity to grow and produce forage for the livestock.

Grass growth varies during the season with rapid growth in May and June and then much slower growth during July and August when the temperatures are higher and moisture is less available. The concept behind rotational grazing is to harvest the grass quickly and then give the forage time to recover and re-grow. This is accomplished by giving the livestock enough grass for the prescribed feeding period and then moving them to a new field. From a production standpoint, the more frequent these moves the more productive your pastures will be. The maximum length of time in a paddock should be 5 days.

Why 5 days? Grass starts to re-grow five days after it is harvested. Think of how long a hay field takes to green up after being cut? Usually in 5-6 days there is new growth started, in a pasture field this new growth is candy to the livestock and they quickly regraze it. This re-grazing depletes the root reserves of the plant reducing the plant vigour and reducing subsequent growth.

An effective rotational grazing system will have the livestock moving to fresh grass every 1-3 days. If you extend beyond this time frame there will be reduced performance by both the livestock and the forage. Think of the pasture field as a feed bunk, would you expect livestock to perform well if the feed bunk was only filled every five days? I don’t think so, we know that fresh feed encourages consumption and increased consumption means increased performance.

For each group of livestock that you have on pasture there should be a minimum of 10 paddocks. This is the minimum number to give the grass an opportunity to recover from the grazing. 20 paddocks will go along way to encouraging increased animal intake and 30 paddocks will allow you to realize the full potential of both the pasture and the livestock that are grazing on that pasture. This may seem like a lot of paddocks but with the use of electric fence and some temporary/portable fence it does not need to be an insurmountable task. Livestock trained to electric fence and accustomed to moving every 1-2 days to fresh grass will meet you at the gate for their next move. Pasture managers who use an effective rotational system find that they have increased carrying capacity, grass growth throughout the grazing season and dramatically reduced need for feeding hay.

Rotational grazing means fresh grass every 1-3 days and a sufficient rest period for the grass to grow to the optimum grazing height (20-40 cm). Rotational grazing at this level

will provide the most high quality forage at the least cost. For more information on rotational grazing, see the websites listed below: www.omafra.gov.on.ca/english/crops/field/forages.html www.ontarioforagecouncil.com www.foragebeef.ca Jack Kyle OMAFRA Grazier Specialist jack.kyle@ontario.ca 705-324-5855

Profile on Organic Farming: Chris Boettcher of Brussels

By Courtney Denard

T

o some, the concept of organic sheep might be an oxymoron. With all of the issues surrounding parasites, they say it’s just too hard to do. Chris Boettcher of Brussels, located in District 3 does not agree. He’s been successfully raising certified organic sheep since 1996, meeting the demand of an increasing market.

Growing up on a conventional cash crop farm, Chris didn’t start off raising sheep. In his last year of high school, however, he decided to mix things up and purchased 30 animals to form a small flock. Over the next few years, the sheep side of the farm continued to expand and eventually Chris, who ran the farm with his father at the time, was working with a flock of about 200. Today, the Boettcher Family Farm runs 360 Canadian Arcott ewes and about 650 lambs, as well as 400 acres of land.

It wasn’t until the birth of his first son Erik in 1989 that Chris began seriously questioning his conventional methods.

“Erik suffered from severe allergies, and in the hopes of helping our son, my wife Gabriele and I started only serving organic food grown on the farm,” he says. According to Chris, the Division of Gamble & Rogers Ltd. change was almost instant.

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This got Chris thinking.

He figured if he could do something to help his own child stay healthy, why not do that for the rest of the population?

“I came more and more to the realization that there was no need to use toxic substances to produce food. I

always thought there must be a way to do it without drugs and herbicides, I just had to find out how,” says Chris.

Lambs: fall oat grazing in October 2007

To do that, Chris (with portable solar powered fence system) took the first step by doing as much research as possible. He read up on organic farming in as many books as he could find. He also turned to organizations like the Ecological Farmers’ Association of Ontario and the Guelph Organic Conference for more advice.

From the Organic Soil Association in the UK, Chris received some information on sheep management and raising cleanmeaning free from pesticides, food pathogens and other contaminants. Finally, in 1996 after many years of hard work, the farm was officially certified as an organic cash crop and sheep farm.

Becoming certified was quite an accomplishment; one that Chris says was very rewarding but also challenging at times. “It’s not like everything was hunky dory the minute we decided to go organic. It definitely was a learning curve to get through, a lot of trial and error,” he says.

One of the ways Chris overcame some of his challenges was by keeping a journal of everything he did on the farm. While at the time journal keeping wasn’t regulation on organic farms (like it is today), Chris saw value in the activity. “My journal was a great resource. I would go back to the book and look at how I handled certain things and I would see what worked and what didn’t,” he says.

To handle one of his other major challenges, parasites, Chris relied on high levels of nutrition and frequent movement of the sheep- something he continues today. At first, Chris tried using herbal dewormers but now he seldom needs any treatment. In fact, with his current production system he has had only one occurrence of parasitic disease, which turned out to be coccidiosis, not nematodes, when he left the flock on the same pasture for too long after heavy rain.

Going organic also provided the farm with opportunity.

“It gave us a whole new market to work with. We used to be locked into wheat, corn and beans but now we can get into oat flakes, rye and spelt,” Chris says. The same goes for the sheep. Chris has three or four consistent buyers who take his product and distribute it mainly to restaurants. He does

Weaning lambs on pasture with portable handling system

Young lamb in May pasture 2009

not do direct marketing but he does sell lamb to health food stores and the stockyards- two other markets he has found lucrative.

love the taste and butchers who cut it have told me the dress is a lot better because they don’t have the thick layer of fat you can get with grain fed,” Chris says.

The sheep on the Boettcher farm are all pasture fed, which benefits in two ways: it facilitates organic weed management on the farm and it’s extremely cost-effective. Plus, grass-fed also means slow-fed. “Sure it may take double the time to fatten the lambs, but it’s worth it. People who order my lamb

In the end, going organic was the right decision for the Boettcher family and is something Chris couldn’t be more proud of. “Our farm is a real family affair with everyone involved and it makes me very pleased to know that together we’re producing a quality healthy product,” says Chris. OSN

Organic Sheep Production – The Facts

by Kate Belbeck, Organic Farm Inspector

T

he term “organic” is becoming more mainstream with respect to food production, but what does organic really mean in sheep production? The answer to that question is ultimately certification. To run a truly organic sheep operation, one needs to be inspected, monitored and certified on an annual basis at minimum by an independent, unbiased certification body. Depending on each producers’ marketing arrangement, there are various Organic Standards to which one can be certified, each with their own set of slightly different rules and regulations depending on the country, and sometimes even the province, in which the organic products are to be sold.

Organic sheep production involves much more than just raising sheep and lambs without antibiotics or hormones.

There are specific standards pertaining to all areas of production including the origins of the livestock, feeding, breeding, healthcare, living conditions, pest management and processing.

Flock Origin - The key starting point with organic sheep production is the flock origin. In particular, one has to take into account the suitability of the particular breed to the environment. However, even more important, is the selection of breeds or lines that show resistance to disease and parasite infestation. Quite often, these breeds are less common and may be harder to obtain.

Preferably, to start in organic sheep production, one should purchase animals from certified organic sources. However, when this is not possible, you can purchase non-bred ewe lambs and rams and transition them into the organic system.

The meat from these starting animals cannot be sold as organic, however, once they are raised in the organic system for a period of one year, they may be sold as certified organic breeding stock. The offspring from these animals can also be sold as organic, both as breeding stock or meat, provided that their dam was raised under the organic standards from the beginning of the last third of the gestation period, or around 95 days of gestation.

Feeding - Organic sheep production requires that all animals be fed a ration suitable to the condition of the animal and the stage of development. This includes the lambs’ need for natural milk, and the sheep’s need for a substantial proportion of roughage in the diet, either by pasture grazing, hay or silage. In the event that silage is fed, hay must also be provided.

In addition, sheep rations must not contain medications or veterinary drugs including prophylactic antibiotics (growth promotants), mammalian or avian slaughter by-products, synthetic preservation or colouring agents, or synthetic appetite-enhancers or flavour-enhancers.

Above all, all feedstuffs, whether grain or forages, fed to organically raised sheep must be of a certified organic origin.

For many producers that grow their own hay or grain, this could mean a 3-year transition period to turn a conventionally grown crop to an organic status. Vacant land that has had any type of chemical treatment such as weed sprays or fertilizers also need to undergo a transitional period.

Continued on page 30.

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Continued from page 29 ~ Organic Sheep Production – The Facts

Breeding - For sheep producers, the breeding standards in organic production are fairly easy to comply with. Organic production favours natural breeding, though artificial insemination is permitted. Embryo transfer is also permitted providing that is does not involve genetic engineering.

Conversely, reproductive hormones used to trigger or synchronize estrus are not permitted.

Healthcare - There are many extensive regulations surrounding healthcare in organic livestock production.

Essentially, it is the producers’ responsibility to minimize the need for antibiotic or parasite treatments. This includes selecting appropriate breeds or strains of animals, supplying feed rations sufficient to meet the nutritional requirements of the animal, establishment of appropriate housing, pasture conditions, space allowances and sanitation practices, and minimizing stress.

Surgical procedures such as tail docking and castration are permitted if they are necessary to improve the health, welfare or hygiene of the animals providing they are performed at the youngest age possible.

Under the organic standards, it is required that animals showing detectable disease, lesions, lameness or injury receive prompt treatment. Treatment should never be withheld to preserve the animal’s organic status.

These animals will then have to be marketed separately, as nonorganic.

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It is important to note that in particular situations, vaccinations, parasiticides and other treatments are permitted, if approval is granted by the certification body prior to their use. The approvals are primarily given if these conditions are not manageable without treatment and pose a welfare risk to the livestock.

Living Conditions - The housing provided to sheep raised in an organic system must accommodate health and natural behavior. This includes access to the outdoors, shade, shelter, rotational pasture, fresh air and natural daylight. Sheep housing must also have appropriate resting and bedding areas, including non-slip floors that must not be fully slatted.

The space requirements for organically raised sheep are as follows: • Indoor space – 1.5m2 per head plus 0.35m2 for each additional lamb • Outdoor space – 2.5m2 per head plus 0.5m2 for each additional lamb Pest Management - External pests, such as flies or rodents, should be managed first by preventative measures, ie.

Removing the source of attraction. Secondarily, mechanical, physical and biological methods can be used. Chemical pest management such as fly sprays or chemical rodent poisons are generally not permitted.

Processing - The steps involved to being a successfully certified sheep operation are extensive and it is extremely unfortunate that one of the most difficult regulations for sheep producers in Ontario to follow is the processing regulation. In order for a producer to sell lamb (meat) as “certified organic”, it must be processed in a certified organic processing facility. At present, there is only one such facility in Ontario, located in Zurich. Until there are more avenues for organic producers in Ontario to have their lamb processed, it can only be marketed as “Certified Organically Grown” as opposed to truly “Certified Organic”. However, despite this current situation, is it not a wasted effort to raise sheep organically.

Overall, there is no simple answer to the question “What is organic?” when it comes to sheep production. There are far too many extensive regulations to cover in such a publication, and these regulations are very much dependent on the situation of each individual producer and their goals for their sheep operation. Products being sold in Ontario, in Quebec or in the United States have different regulations though the same general principles apply. Of the utmost importance though is certification. Certification is the assurance to the industry and the consumer that you are producing what you claim to be, in an appropriate and acceptable manner.

Ultimately, if it’s not certified, it’s not organic.

For more information on the certification process and standards in Ontario, contact Pro-Cert Organic Systems Ltd. at 705-374-5602 or go to www.pro-cert.org. OSN

Teaching Organic Sheep and Goat Management and a Lesson in Parasite Management

By Colin Lundy

I

n 2008 Canadian Organic Growers (COG) published the first of its Practical Skills Handbooks titled “Living With Worms in Organic Sheep Production”, written in part by Peter Stockdale, an organic sheep farmer in the Okanagan region and a retired veterinary parasitologist. Coincidentally, the same year brought some of the wettest weather on record in Ontario and Quebec. Where I live in Eastern Ontario there were only seven days in June without precipitation giving an accumulation of 107 mL (about 40% above normal amounts).

Wet weather made living with worms a difficult challenge for sheep and goat raisers in the region. Increasing incidents of parasitic resistance to anthelmintic dewormers adds a whole other dimension to the struggle.

Recognizing that parasite pressure is often the last (and arguably the largest) obstacle preventing sheep and goat raisers from being organic, and the confluence of the publication of “Living With Worms” with a pasture season bearing a heavy parasite load, COG-Ottawa Chapter organized a workshop day on organic sheep and goat raising with a focus on managing parasites. To the knowledge of COG-Ottawa, such a course has never before been offered in Eastern Ontario, and perhaps in Canada. Therefore, we had to find local organic sheep and goat farmers who were not only raising flocks without using anthelmintics, but also willing to develop a curriculum and deliver a course to other interested farmers.

In the end we were lucky to find two farmers interested in facilitating the course. Achim Mohssen-Beyk owns Reachview Farm, a 250 certified organic farm near Picton, Ontario.

He raises certified organic Katahdin and Tunis sheep and Nubian and Saanen goats, as well as other livestock, some fruits and vegetables and field crops, hay and pasture. At their height, Achim’s flocks were about 150 ewes and 20 does, but have recently been cut back to 60 ewes and 8 does. Achim participated in the Sheep Parasite Research Program of the University of Guelph and the Organic Agriculture Centre for Canada, and was told that his farm had amongst the lowest intestinal parasite counts of all participating farms. Achim is also a past board member of COG and the Ecological Farmers Association of Ontario (EFAO), and is currently a trained facilitator for EFAO and acting Vice President for Organic Conferences of Canada.

Peter Smith owns Fair Weather Farm, a certified organic sheep and vegetable farm near Osgoode, Ontario. He currently manages a flock of 25 Katahdin ewes, with plans to increase to 50 ewes. Peter’s sheep do not get any grain, but only good quality pasture, hay and the occasional vegetable culls.

Peter is also an organic certification inspector for one of the prominent certifying bodies operating in Canada.

Neither of the course facilitators is a “born” farmer.

Therefore, acquiring knowledge is the key to their success.

Twenty-three participants attended the course in Ottawa in February of this year. Most were conventional farmers feeding grass and grain. A few were non-certified organic farmers and one was certified organic. Many raised both sheep and goats, with some raising only sheep and a couple raising only goats.

Sheep flocks were generally much larger than goat flocks although there was a lot of variety. Sheep flocks ranged from two ewes to 650 ewes. Goat flocks ranged from one doe to 112. There was one participant with no sheep or goats but was building knowledge for when he does acquire a flock.

The remainder of this article will briefly describe some of the main points and learning highlights of the day, but is by no means exhaustive.

The challenge of parasite management affects both organic and conventional sheep and goat raisers. However, according to Achim and Peter, organic soil, pasture and feeding management strategies offer many advantages over the conventional strategy of routine deworming of entire flocks using anthelmintics. In other words, the approach of organic sheep and goat management is to create an environment where parasites are unable to overwhelm a flock’s health, rather than continually using drugs to treat symptoms rooted in poor flock management.

Flocks should be pastured in paddocks and moved to other paddocks frequently, especially in wet weather. Parasites lay eggs in the animals’ intestines, which are excreted onto pasture.

Eggs then hatch and climb to the tops of blades of grass to be readily consumed again by the animals. By this process, the animals are continually increasing the parasitic load in their intestines, until they are overwhelmed, leading to disease and death.

Therefore, the flock should be moved to a new paddock to prevent the eating of more generations of parasites. The flock should not be returned to the same paddock for several weeks, or even months, depending on soil, climate and weather Browsing through the “Living With conditions. Waiting longer Continued on page 32.

Worms” handbook and other resources on organic agriculture.

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Continued from page 31 ~ Teaching Organic Sheep and Goat Management and a Lesson in Parasite Management

to return a flock to a pasture not only allows manure to compost and pasture to regenerate, but also allows wind and sun to dry out and kill parasites in that pasture. This disrupts the breeding cycle of parasites and reduces the overall parasite load in any given animal’s intestine.

Healthy (living) soil is also critical to pasture health and thus to livestock health. Therefore nutrients should be returned to the soil as much as possible by pasturing, spreading manure and compost. Soil tests should be conducted to determine if other organic amendments also need to be added to the soil for proper nutrient balance. Pasture and hayfields should be diverse, including grasses and clovers, both for the benefit of the livestock and for soil. Some weeds such as chicory and wormwood, not only draw up micronutrients from the subsoil, but also may have anti-parasitic Achim Mohssen-Beyk describing the management of his sheep and goat flocks. affects when consumed by sheep and goats. Achim particularly stresses that hay should be cut as little as possible.

Cutting hay is removing nutrients without returning them, unless compost and manure can be spread. Furthermore, he estimates that topsoil loss due to haying is approximately equivalent in weight to the amount of hay taken off!

Achim gives small amounts of grain only at the onset of lactation and Peter gives no grain at all. While diplomatic about this sensitive issue, the two facilitators felt that grain is difficult for sheep and goats to digest and disrupts the pH of the digestive system. Ultimately, grain feeding compromises the health of sheep and goats, making them vulnerable to further health problems. Weaning of lambs and kids is done late or whenever the lambs and kids wean themselves. This encourages robust and healthy lambs and kids, and reduces the time spent eating hay and/or pasture hosting parasites.

Breeding is another factor that impacts the effect of parasites on a flock. Both Peter and Achim manage their flocks, but in different ways. Peter selectively breeds to encourage strong, healthy and robust lambs. Achim tends to not interfere with the natural breeding of his flock, but instead aggressively culls his flock. Young males are marketed first, and then second choice females. He also culls all sheep and goats exhibiting chronic health problems and undesirable traits. In both cases, the criteria for selection likely intuitively promote either resilience or resistance to worm pressure.

There was a little discussion about housing for goats and sheep. Housing requirements, and general protection from sun, wind and cold, are minimal. Extended periods in the barn only increase the potential for increased consumption of parasites, respiratory problems and other health issues. When animals are kept in the barn, sanitation, thick clean bedding and good airflow are critical.

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The bottom line is that soil capable of growing good quality pasture coupled with rigorous flock management results in a strong healthy flock. Even though parasites are present, the animals are neither vulnerable to, nor do they succumb to, parasitic disease. There are several natural dewormers permitted in organic production such as a garlic tonic, Hoegger’s herbal wormer, Diatomaceous Earth, and some homeopathic remedies. Some people swear by them. Peter has tried some of these alternative dewormers with inconclusive results. He stresses good management, as described above, to be the best strategy.

Apart from the discussion about raising sheep and goats organically, part of the day was spent talking about what organic certification means and how it works. While most of the course participants were conventional, several were there to learn more about organic production, so there was some interest about the organic certification process. There was also interest in discussions surrounding marketing certified organic meat, including the challenges due to the fact that there are no abattoirs in the region with organic certification (The Organic Standards and Regulations acknowledge and account for this gap, but it would be better if there were abattoirs with organic certification).

Overall, the day was deemed a success. Feedback was quite positive and new knowledge was learned. Participants valued learning in detail how two certified organic farmers are managing their sheep and goat flocks without using anthelmintic drugs. Nonetheless, as a first time event, there is room for improvement. Most of the participants were veteran sheep and goat farmers. While participants learned from this course, many felt it needed to go beyond general discussions about pasture, flock and parasite management. Participants desired more detailed, specific and technical knowledge about the components of soil health, parasite biology, and organic treatments for parasites.

Luckily, COG’s handbook “Living With Worms in Organic Sheep Production” offers some of that technical knowledge as well as resources for further research. The book is not thick, but its subject matter is focused and to the point. Worms will always be present in sheep and goat intestines. The handbook advises how to manage livestock and parasites so that parasites are unable to overwhelm the health of the animals.

“Living With Worms”, other organic farming books published by COG and other resources about organic production and organic certification can be obtained from COG’s website: www.cog.ca. In addition, one outcome of this course is that COG may begin hosting an online forum facilitating the exchange of knowledge between farmers about organic sheep and goat production. This is still a conceptual idea, but eventually such a forum will be accessible from the COG website. OSN Colin Lundy is Farmer Outreach and Training Coordinator for COG-Ottawa. He organizes training and other networking activities for the benefit of organic farmers and conventional farmers interested in learning more about organic production.

Colin and his wife, Eylie, raise organic fruits and vegetables near North Gower, Ontario. Just recently, Colin learned a lot about raising goats and sheep! He can be reached by emailing colin@cog.ca or phoning 613-489-2948.

The Digestive System In order to make use of the nutrients stored in feedstuffs, all animals must first break down (digest) feed into a form that can be absorbed by the body. The focus of this chapter is to provide a basic overview of the structures, abilities, and limitations of the sheep’s digestive system. Sheep belong to a group of herbivores called ruminants. Ruminants are able to digest a large portion of the nutrients contained in fibrous plant material due to their unique digestive system, which integrates a large microbial population with the animal’s own system. Although this system is remarkably efficient, proper feeding management is needed to maintain healthy and productive animals. Mismanagement of a ruminant’s diet can be disastrous.

Structures of the Digestive System: The digestive tract is composed of the mouth, esophagus, stomach, small and large intestines, and anus.

Various other structures and organs, such as the salivary glands and liver, also aid in digestion. A few of the key structures are described below: Salivary glands: There are three sets of glands that drain saliva into the mouth. The saliva mixes with the feed that is being chewed and is swallowed with the feed. Saliva, which has a high pH, is very important in maintaining the correct pH balance in the rumen and is a key component of rumen fluid. Therefore, the salivary glands in ruminants are extremely productive. An adult sheep, for example, may secrete over 25 litres of saliva per day.

Esophagus: The esophagus is a long muscular tube that runs to the stomach. When feed is swallowed, muscles in the esophagus move the food to the rest of the system Stomach The stomach of ruminants greatly differs in structure and function compared to monogastrics (dogs, pigs, horses, humans etc.). Monogastrics have a relatively simple, single-chambered stomach. Sheep, like other ruminants, have three additional chambers (reticulum, rumen, and omasum) that feed passes through before reaching the ‘true’ stomach (abomasum).

Reticulum: The reticulum is a blind pouch of the rumen that acts as a holding area for feed after it passes down the esophagus. The reticulum receives material coming into the digestive system and will trap large inedible objects. As there is no distinct division between the rumen and the reticulum, they are often referred to together (reticulo-rumen).

Rumen: The rumen is a very large muscular pouch, which extends within the left side of the body cavity from the diaphragm to the pelvis. The rumen is a critical site for feed digestion in ruminants. The rumen has a complex environment composed of microbes, feed at various stages of digestion, gases, and rumen fluid. The microbes (bacteria, protozoa and fungi) number in the billions and are the basis of the fermentation (digestion) process. The rumen contents separate into three zones based on their density and particle size: gas (fermentation by-product) rises to the top; small, dense particles sink to the bottom (grain, well digested forage), and lighter, longer particles form a middle layer on top of the rumen fluid (recently eaten forage). Feed remains in the rumen until the particles are small enough to pass into the omasum.

Approximately 70% of the energy requirements of the animal are supplied through microbial activity in the rumen. As proteins vary in how easily they can be dissolved within the rumen fluid, the amount supplied through the rumen depends on the type of protein being provided in the diet. Some types of proteins will be completely dissolved and utilized by the microbes, while other types pass from the rumen intact (by-pass proteins).

Omasum: The omasum is much smaller than the rumen. It grinds feed particles (digesta) coming from the rumen/reticulum to reduce the particle size and to absorb excess moisture. As fermentation requires large amounts of fluid, it is important to recapture water to avoid dehydration. From the omasum, digesta proceeds into the abomasum.

Abomasum: The abomasum is called the ‘true’ stomach. It functions in a similar manner as the stomach of a monogastric, including the production of acids to aid in digestion of certain feed components. Protein that is insoluble in the rumen fluid, a small percentage of starch, and any fats in the diet are passed from the rumen into the abomasum relatively intact. As large numbers of microbes are also flushed from the rumen, the abomasum is specialized to break down the microbes. These microbes are an important source of nutrients for the ruminant.

Small intestine The small intestine is the main site of absorption of nutrients that have by-passed the rumen. The small intestine is approximately 85 feet long in adult sheep. Bile and pancreatic juice drain into the small intestine to aid in digestion of certain feed components, such as dietary fat.

Liver The liver is a large organ, about 1.5% of an animal’s live weight. It is located towards the front of the animal’s body cavity, just behind the diaphragm. Newly digested and absorbed nutrients are transported from the absorption sites to the liver for storage and/or further processing. The liver also produces bile that drains into the intestine to aid in the digestion of fats.

Large intestine The mammalian large intestine consists of the caecum and the colon. The caecum is a blind pouch that opens into the digestive tract. In ruminants, approximately 10-15% of the animal’s energy requirement is supplied through microbes in the caecum.

The Digestive System in Lambs When lambs drink milk, the rumen and reticulum are generally by-passed. Suckling causes a reflex action bringing the walls of the reticulum together to form an esophageal groove leading directly to the omasum. This reflex is very important in newborn lambs, to ensure that antibodies in the colostrum are transported intact to the abomasum. The esophageal groove generally does not form when lambs are fed milk by a stomach tube. Without the reflex, the milk will end up in the reticulum and may cause bloating, as the milk will be poorly digested.

During the first few weeks of a lamb’s life, the rumen is very small and has no microbes. The rumen will become functional as the lamb begins to consume more plant material and the rumen is ‘seeded’ with microbes.

Rumen Function: Rumen microbes Everything that the sheep eats is subjected to microbial digestion. The feed you see your sheep consume is actually, for the most part, being used to feed and maintain the rumen microbes. The microbes in turn provide nutrients to the sheep. Like any other organism, the microbes need to be fed. If an animal is held off feed for a few days, the microbial population will die. If this occurs the ruminant will be unable to utilize feed until microbes are reintroduced to the rumen.

Microbes secrete enzymes directly onto the feed particles and into the rumen fluid. Therefore, feed is broken down directly by the microbes and also by the surrounding fluid. Unlike many mammalian groups that rely on both carbohydrates and fats, the vast majority of energy in ruminant diets is supplied through plant carbohydrates. Plant carbohydrates are classified as either insoluble or soluble, based on how easily they can be digested. The rigid, fibrous plant cell wall is largely comprised of insoluble carbohydrates (mainly cellulose), while the inside of the cell contains more soluble forms (starch, hemicellulose etc.). The cell walls of different types of plant material and plants at different stages of development will vary in thickness and therefore contain different proportions of soluble and insoluble carbohydrates. Much of the nutritive value of plants with thick cell walls (forages) is unavailable to mammals without microbes to break down the cellulose. Feeds high in starch (e.g. grains) provide more readily available energy than feeds high in cellulose (e.g. forages).

As microbes are breaking down and utilizing carbohydrates in the rumen, they produce energy rich by-products called volatile fatty acids (VFA's). It is the VFA’s rather than the original plant material that provide energy to the ruminant. The VFA’s are absorbed by the animal through the rumen wall, after which they are carried through the blood system to the liver for further processing and storage. There are many types of microbes in the rumen. Although their functions vary and even overlap in some cases, they can be classified into two general groups based on the type of carbohydrate that they digest. One group is adapted to breaking down the fibrous cell wall (cellulose), while the other group digests soluble particles (starch). Therefore, the composition of the microbe population (cellulose digesters vs starch digesters) will vary depending on the type of feed provided to the sheep.

Rumen pH The normal environment of the rumen is neutral (pH of 6 to 7) and most rumen microbes can only thrive in this type of environment. Therefore, the acidic by-products of fermentation must be removed from the rumen continuously by absorption through the rumen wall and saliva (high pH) must be added to the rumen fluid frequently to maintain the proper pH. Many of the digestive problems in ruminants occur when the mechanisms regulating the pH balance are disrupted and the rumen becomes too acidic (acidosis). As discussed below, the diet and the microbe population have a direct influence on the rumen pH. Increased fermentation rates can lead to a rapid decline in rumen pH. The speed of digestion is dependent on the type of feed and the particle size.

Type of feed and changes in diet Ruminants can adapt to diets with different levels of forages and grains. However, sudden changes from forage to easily digestible feed can cause a major disruption in the microbe population of the rumen. For instance, the rumen microbe population of an animal fed only grass hay will be largely comprised of cellulose-digesting microbes. If the diet is suddenly switched to a high grain, low forage ration, it will take time for the population of MOST starch-digesting microbes to increase. This creates a favourable environment for a population explosion of o ne particular type of starch-digesting microbe. This microbe produces large levels of lactic acid.

Although a small amount of lactic acid is a normal by-product of fermentation, very large levels will cause the rumen pH to drop below 5. This will kill the cellulose-digesting microbes, and prevent the growth of other types of starch-digesting microbes. As the lactic acid microbes are able to survive in a low pH environment, their population will continue to increase, further adding to the drop in pH. This is a very serious situation for a ruminant. At the very least, rumen function and feed utilization will be slowed, and the rumen will need to be re-populated with essential microbes. In severe cases, the animal could die, due to bloat or lactic acidosis. It is very important, therefore, to make changes to high-energy diets slowly. If grain is increased incrementally over a few weeks the transition in the microbe population will occur gradually, preventing an overpopulation of the lactic acid producing microbes. Even with animals adapted to high-energy diets, precautions should be taken to prevent disruptions in microbe populations

(i.e. maintain a regular feeding schedule and prevent animals from ingesting very large amounts of easily digestible feeds at one time) Particle size: Very small feed particles can be quickly surrounded and digested by microbes, increasing the fermentation rate. One way to moderate the digestion of small particles, such as grain, is to provide the animal with sufficient fibre. As mentioned earlier, the long fibres of recently consumed forages settle in the middle region of the rumen, where they form a structure known as a rumen mat. When a mat is present, it will entangle small particles (e.g. grain, alfalfa leaves), which helps limit their exposure to microbes and slows their digestion. It is important to note that in the case of very fibrous feeds (straw), particle size may need to be decreased. This type of feed may be chopped to reduce the particle size to help increase intake and digestion.

Rumen Gases: Large quantities of gas are produced within the rumen as a by-product of fermentation. (~5 litres per hour in a sheep). Ruminants need to frequently rid themselves of these gases, mainly through eructation (belching). Bloating occurs if the animal is unable to release gas or if gas is produced faster than it can be released. If bloating is severe, the rumen enlarges to the point that it pushes against the lungs, potentially suffocating the animal. The rate of gas production is dependent on the speed of fermentation, which (as noted above) varies with the type of feed and the particle size. Rumen pH is also a factor for gas release as it affects rumen motility (see below). There are two types of bloat: • Frothy bloat occurs when the gas becomes trapped within the rumen fluid creating a frothy layer. As the gas is not in a ‘free’ form, it cannot escape the rumen. This type of bloat most frequently occurs when animals are fed high protein forages (legumes) that have a small particle size (e.g. alfalfa with a high percentage of leaves or finely chopped forage). Precautions should be taken when switching sheep to legume hay, and particularly, when first turning sheep into pastures with a high legume content.

• With free gas bloat, the gas forms a distinct layer, but the animal is unable to release it because of decreased rumen motility (see below).

Rumen Motility Approximately every half-minute, the rumen and reticulum are subjected to strong muscular contractions which cause churning and mixing of the rumen contents. The highest frequency of contractions occurs during feeding. The rumen environment significantly affects motility, and motility will slow down or cease (rumen stasis) if rumen contents become overly acidic. Consequently, the type of diet will influence rumen motility, with high-fibre diets increasing motility relative to low fibre diets.

Rumen motility aids rumen function by: a. Increasing efficiency of digestion: Churning of the rumen contents helps increase the exposure of feed particles to microbes.

b. Release of gas: As mentioned earlier, the gas produced during fermentation remains in the top portion of the rumen. As the rumen contents are moved by muscles contractions, the gas bubble is shifted to the esophageal opening, allowing for eructation. If the contractions are decreased by a low pH, gas release will be decreased and the animal may bloat (free-gas bloat).

c. Ruminating or ‘chewing cud’: Rumen churning also stimulates cud chewing. The passage to the omasum is narrow which limits the size of the particles that can be passed into the rest of the digestive system. While feeding, ruminants take fairly large bites and swallow the material with little chewing. Therefore, sheep must continue to physically break down the feed after it has been swallowed the first time. At regular intervals boluses of feed (cud) being held in the reticulum are brought back up to the sheep’s mouth to be further chewed and then swallowed again. This process (rumination) reduces the size of the forage particles and greatly increases the surface area available for microbial digestion. Rumination also increases rumen pH by stimulating the release of saliva. d. Digesta movement to the omasum: Rumen contractions help move digested rumen contents into the omasum. Impaction of the rumen may result if motility is suppressed for a significant length of time.

Summary: Feeding for a Healthy Rumen •

Feed sufficient fibre: Ruminants are designed to consume and digest forage, and producers will generally have few problems if a high percentage of the diet consists of grass forages (~1.5% body weight). Although high grain rations can be successfully fed, animals receiving this type of diet must be managed carefully to avoid digestive disturbances. Providing forages together with grains helps to ensure that the high-energy feeds are not digested too quickly, by producing a rumen mat.

A diet high in forages also aids in maintaining the rumen pH by increasing rumen motility and encouraging rumination.

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Feed at regular intervals: This will help maintain continuous fermentation and prevent acidosis by maintaining a consistent population of bacteria (i.e. no sudden die-offs or explosions in microbe numbers).

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Make ration changes gradually: Ration changes should be made over a two-week period to allow the rumen microbes time to adjust. This is particularly important when switching from a low energy diet to high energy feed (i.e. going from a grass forage diet to either a high grain or high alfalfa diet). Making ration changes too quickly can lead to digestive disorders such acidosis and bloat.

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Take precautions with high-energy diets or feeds with fine particle size: Even if an animal is adapted to a high-energy diet, a sudden intake of grain may cause digestive disturbance through a rapid decrease the rumen pH (acidosis), causing rumen stasis.

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Feed forage before grain or provide free choice forage: This helps ensure the formation of a rumen mat to slow the fermentation rate of grain and maintain rumen pH.

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Do not severely limit energy: Although most of the recommendations above deal with providing too much energy, only feeding very low energy, fibrous feeds (e.g. straw alone) may also cause problems. As the opening from the rumen/reticulum to the rest of the digestive system is small, feed particles must be small to pass through, and make space in the rumen for new feed. With very fibrous feeds, the rate of passage is too slow to meet the energy requirements of the animal.

Although there may be lots of feed available, the animal will be limited by the capacity of the rumen. Very fibrous feed may also lead to rumen impaction, if the feed is unable to pass to the omasum.