BEEF CATTLE PRODUCTION SERIES - PART 7 by TSCRA - The Cattleman Magazine

BEEF CATTLE PRODUCTION SERIES â&#x20AC;&#x201C; PART 7

Heifer Nutrition, Cow Condition, Nutrition for Second-Trimester Cows

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BEEF CATTLE PRODUCTION SERIES – PART 7

Heifer Nutrition, Cow Condition, Nutrition for Second-Trimester Cows Table of Contents 4 The Nutrition Behind Turning Heifers Into Productive Cows 8 Consider Cow Condition After Weaning and Well Before Calving 11 Make Sure Second-Trimester Cows Get the Right Nutrition

The Cattleman, the monthly journal of Texas and Southwestern Cattle Raisers Association, is pleased to partner with Merck Animal Health on a series of seasonal beef cattle health management manuals. Thanks to the generous support of the Merck Animal Health technical services veterinarians, we are able to provide easy-to-read articles that educate and inform ranchers about various aspects of beef cattle health management. thecattlemanmagazine.com

Merck Animal Health BEEF CATTLE PRODUCTION SERIES – PART 7

The Nutrition Behind Turning Heifers Into Productive Cows By Gary DiGiuseppe

The heifers you are planning to breed in the next season are still growing, and Dr. Marshall Streeter says one of the biggest challenges is getting them to grow at the right rate. Streeter, technical service manager-cattle for Merck Animal Health, says the goal is twofold — the heifer must reach a target weight and body condition score so she will cycle and be ready to breed, and she should not get too fat. The heifer’s feeding situation differs from that of cows or calves, so she needs more management. “If we feed her in a dry lot situation, we can control the rate of gain by supplying appropriate amounts of energy, protein, vitamins and minerals,” Streeter says. “If she is grazing, the nutritional management needed to achieve specific growth rates and body weight may be more challenging.” Lush pastures may allow heifers to become fatter than desired, resulting in calving problems and an increased need for assistance. Drought conditions or mature forage conditions can result in an inadequate plane of nutrition; one that does not allow a heifer to grow fast enough to achieve the minimum body weight necessary to reach puberty prior to the breeding season. Weight and body condition of heifers can vary greatly, depending on forage conditions prior to weaning: droughty, lush or

somewhere in between. Additionally, calf management prior to weaning influences weaning weight and body condition — for example, if they were weaned early in order to improve body condition of the cows or because of drought conditions. Ranchers are typically already set up to manage heifers. They have programs they have used in the past, so decisions such as whether to put heifers out on dormant winter range or feed them in a dry lot after weaning are already made. If placement will be on dormant or winter range, Streeter says the biggest point of management is the protein and energy availability needed for the heifer to grow at the correct rate. Three phases of replacement heifer development Development of replacement heifers can be broken into 3 distinct phases during which the heifer’s nutritional needs and growth rate targets differ. The first phase is pre-breeding, covering the period from weaning to breeding. The second covers the period from breeding to calving, and the third represents the relatively short span between calving and rebreeding. If heifers are grazing, nutrient supplies and nutritional demands for growth, gestation and lactation vary greatly among the 3 phases.

4 Merck Animal Health BEEF CATTLE PRODUCTION SERIES – PART 7 thecattlemanmagazine.com

Phase 1 During the first phase, the main goal is achieving an adequate plane of nutrition to ensure that heifers reach puberty 30 to 45 days prior to breeding. The growth rate typically needed to accomplish this goal ranges between 1.25 and 1.75 pounds per day. The exact growth rate depends on the heifer’s weaning weight, breed, the time between weaning and breeding, and the expected mature weight once she becomes a cow. Streeter says the goal should be for heifers to come into the pre-breeding season having attained 60 to 65 percent of their mature weight 30 to 45 days prior to the beginning of the breeding season, and having a body condition score of 6 or greater. Reaching puberty is a function of a heifer’s age and body weight. Breeds with a greater mature body size may take additional days to attain 60 percent of their mature weight even though they may also have slightly greater growth rates. To determine the exact growth rate, simply subtract weaning weight from 65 percent of mature weight and divide by the number of days between weaning and pre-breeding (30 to 45 days prior to breeding). This will provide the exact daily gain needed. Mature weight can be estimated from the pay weight of cull cows, with consideration given to their fatness. The reason for the target weight and timing is breeding readiness. The heifer is typically ready to cycle when she reaches 60 to 65 percent of her expected mature weight, provided she is at that body condition score of 6 or better. Therefore, if she attains those targets ahead of the breeding season, she can cycle at least once prior to breeding, while the producer monitors her growth rates to ensure she is meeting the desired targets and will be ready to breed come spring. “One would ideally obtain the weaning weight and an interim body weight between weaning and breeding to provide a direct measure of growth rate, rather than relying on visual observations and estimates of growth,” Streeter says, “but that is not always realistic or representative of what actually happens. Many times a visual appraisal is used to estimate body weight, which is probably more an observation of body condition than of weight. “The assumption is that if a heifer is meeting body condition expectations, then she is probably also able to meet the growth rate needs. If one runs into a situation where expectations are not being met, nutrition resources need to be adjusted to ensure that the heifer can catch up, otherwise, she will get bred late, if at all.” It may be necessary and beneficial to separate heifers into body weight groups if they have a wide range of body weights at weaning or grow apart during the pre-breeding phase. thecattlemanmagazine.com

Phase 2 The second phase consists of breeding until calving. Like a mature cow, the nutritional requirement of heifers varies greatly with the stage of gestation. Unlike a mature cow, heifers have an additional nutritional demand for continued growth. The last trimester of gestation results in the period of greatest nutritional demand. Growth rates needed to meet weight targets are lower during this phase, typically in the range of 0.8 pounds per day. However, because of the length of this period and the various seasons involved, meeting nutritional needs requires planning. At the time of calving, heifers should have reached approximately 80 percent of their mature weight. Phase 3 The third phase covers the period from calving until rebreeding. At this point in the maturation process, heifers should be between 80 and 85 percent of their mature weight. Nutritional demands for growth will have been reduced compared with the 2 previous phases because the heifer is approaching her mature weight. However, nutritional needs to support lactation during the breeding season require that special attention be paid to first-calf heifers. Energy and protein supply In all 3 phases of heifer development, energy and protein supply are the greatest concerns to ensuring adequate growth. Adequate protein would not normally be a concern early in the grazing season, but when grass matures, one may need to consider protein supplementation. Depending on the region of the country, energy may or may not also become a factor later in the growing season. “There is quite a bit of variation in Texas, depending on whether you are in the eastern or the western part of the state,” says Streeter. “If the cattle need a nutritional supplement, it would typically be late in the growing season when the energy and protein content of the forage is decreasing, or when forage is already dormant. In some areas of the country, typically eastern and central, protein supplementation in the face of adequate forage supply can result in improved protein and energy status. However, in western native range conditions, protein supplementation alone has shown mixed results in attaining the proper energy status to maintain growth rates. Additionally, geography often creates more challenges for supplementation in pastures in the western part of the state, where land mass per animal is quite different than in the east.” It is important to start with a clear understanding of what the heifer’s needs might be, and what is inherently available in the forage resource. “People typically think of an animal’s requirement as being a percentage,” Streeter concedes. “If the forage was Merck Animal Health BEEF CATTLE PRODUCTION SERIES – PART 7

12 to 14 percent protein, one might say that is going to meet a heifer’s protein requirement. However, the heifer’s requirement is actually a physical amount of protein per day, so the challenge is not just what the protein content or percentage is in the grass, but also how much one expects her to eat.” Because it is easier to assess the protein percentage via testing than to assess the heifer’s daily forage intake, a more practical solution is to evaluate a heifer’s weight and condition to determine whether she is receiving adequate nutrition. If the animal is not meeting those nutritional requirements, she will not attain the weight or condition needed to reach puberty prior to the breeding season. Growth could be limited by a lack of protein, energy, minerals (phosphorus, copper, zinc), or vitamins (vitamins A, D, E). With forage-based systems where heifers receive a vitamin and mineral supplement, one might expect protein to limit growth rate. If the rancher monitors the protein content of the forage and has an estimate of forage consumption, the rancher can determine whether protein is the factor limiting growth. Are the heifers familiar with the supplemental feed? If improving a heifer’s body condition via supplementation is needed, consider the animal’s familiarity with feed ingredients and the delivery forms of nutrition. Streeter says, “If one is raising their own heifers, I would use a feedstuff and delivery form that heifers were exposed to while on the cow or during the weaning period. If they are familiarized with a supplement prior to weaning, one may benefit from exposing heifers during weaning to a feedstuff and supplement form that will be used in the future. By that, I mean putting them in a smaller paddock early on, where one can aid cattle in finding and consuming the supplement.” He says it is important to train heifers to seek out the supplement source to improve supplement consumption when forage nutrient supplies are dwindling, rather than waiting until forage nutrient resources are already inadequate. Forage resource tends to leach nutrients, not just protein, but mineral and vitamins as well. He explains, “The time you are most likely to need a supplement may be later, after weaning, and yet at that point, it is harder to train cattle to come to a supplement if they have not had prior exposure.” One of the axioms of nutrition is that there can be a first limiting nutrient. Because they are such a significant portion of the ration, protein and energy come to mind first as the limiting nutrients; however, growth can also be limited if daily micronutrient requirements of either the vitamins or minerals are inadequate. From a ruminant perspective, the rumen itself provides the bulk of the animal’s water soluble vitamins (B-complex).

However, vitamin A inadequacies have been associated with decreased conception rates and increased age at puberty. Vitamins E and D are also vital to the heifers’ growth and development. Consequently, vitamins A, D, and E must be supplemented so that heifers consume their daily requirements. Minerals, though, are completely different. They are solely provided by an exogenous source, be that forage or a supplement. Therefore, if forages are deficient in minerals, they must be supplemented to allow heifers to reach growth rate targets. The minerals that receive the most attention relative to reproductive efficiency are phosphorus, copper and zinc. Copper can be particularly problematic in areas with high-iron soil. This soil results in increased iron accumulation in forages, and iron interferes with the absorption of copper. Unthriftiness One of the warning signs that a heifer will not be ready for the breeding season is unthriftiness — the failure to grow or put on weight as well as expected in the presence of adequate quantity and quality of feed. Streeter says that one must separate disease and parasite concerns from the nutritional supply as a reason for reduced growth. Parasites, sub-clinical bovine respiratory disease, or prior clinical bovine respiratory disease, in particular, can create an unthrifty condition and result in reduced growth rates. He says, “It is just one more management consideration to have in understanding why cattle may have reduced growth and a rougher hair coat than expected. He recommends involving a local veterinarian to address disease concerns and consulting with a nutritionist or a feed manufacturer representative to discuss what the limiting nutrients are in the producer’s area. Most ranchers do not have trouble preparing a heifer to become a cow. Streeter says most operations already have programs in place; health programs developed with local veterinarians and supplement programs developed with a nutritionist or local feed representative. These resources can also assist in adjusting the health and nutritional programs to ensure that nutritional needs are met and the growth rate goals are accomplished. These are rare times, however, with signs of cow herd rebuilding and grass growth in areas that have survived several years of debilitating drought. Consequently, there are producers holding back more heifers than in the past several years, or developing replacement heifers for the first time in a while. Streeter says, “It is a good idea to review body weight goals and health protocols to ensure that heifer replacements become productive cows.” ❚

6 Merck Animal Health BEEF CATTLE PRODUCTION SERIES – PART 7 thecattlemanmagazine.com

IS YOUR DEWORMER PASSING THE TEST? AVERAGE PERCENT EFFICACY2 90% Required to Pass 4

P 99.6%

PASS FAIL

F 83.5%

80%

F 70%

Consult your local veterinarian for assistance in the diagnosis, treatment and control of parasitism. IMPORTANT SAFETY INFORMATION Safe-Guard EN-PRO-AL Molasses Block RESIDUE WARNING: Cattle must not be slaughtered within 11 days following last treatment. A withdrawal period has not been established for this product in preruminating calves. Do not use in calves to be processed for veal. Safe-Guard Protein Block RESIDUE WARNING: Cattle must not be slaughtered within 16 days following last treatment. A withdrawal period has not been established for this product in preruminating calves. Do not use in calves to be processed for veal. Safe-Guard Mineral, feed through products and liquid feed RESIDUE WARNING: Cattle must not be slaughtered within 13 days following last treatment. For dairy cattle, the milk discard time is zero hours. A withdrawal period has not been established for this product in preruminating calves. Do not use in calves to be processed for veal.

60%

Safe-Guard®/Panacur®

LongRange® Injectable

Dectomax® Injectable

Cydectin® Injectable

Ivomec® Injectable

Safe-Guard®/Panacur® Plus an Avermectin

72.3%

The FDA has identified growing levels of internal parasites resistant to the Macrocyclic lactones (Avermectin) class of dewormers.1

98.7% 90%

78.4%

49%

100%

50%

40%

Results from the Merck Animal Health Fecal Egg Count Reduction Test National database2 shows several cases of internal parasite resistance and supports concurrent treatment protocol to manage resistant parasites. The majority opinion among parasitologists attending the FDA public forum on managing resistant parasites was that concurrent treatment of two different classes of anthelmintics is the best way to manage these resistant parasites. Merck’s database supports 2008 USDA National Animal Health Monitoring Study (NAHMS) showing confirmed or suspected resistance in several U.S. states to Macrocyclic lactone (Avermectin) class of dewormers.3

ADD SAFE-GUARD ADD POUNDS

Safe-Guard Drench and Paste RESIDUE WARNING: Cattle must not be slaughtered within 8 days following last treatment. For dairy cattle, the milk discard time is zero hours. A withdrawal period has not been established for this product in preruminating calves. Do not use in calves to be processed for veal. Safe-Guard is a registered trademark of Merck Animal Health. Panacur is a registered trademark of Merck Animal Health. Ivomec is a registered trademark of Merial, Ltd. Cydectin is a registered trademark of Boehringer Ingelheim Vetmedica. Dectomax is a registered trademark of Zoetis. LongRange is a registered trademark of Merial, Ltd. 1 FDA Public Resistance Forum-March 2012 2 Tests from 1/1/2008 - 4/12/2016 3 NAHMS 2008 4 Dobson R., Jackson F., Levecke B., Besier B., et al. Guidelines for fecal egg count reduction tests (FECRT). World Association for the Advancement of Veterinary Parasitology (WAAVP) (2011) Proceedings: 23rd International Conference of the World Association for the Advancement of Veterinary Parasitology 2 Giralda Farms – Madison, NJ 07940 – merck-animal-health-usa.com – 800.521.5767 Copyright © 2016 Intervet, Inc. d/b/a Merck Animal Health, a subsidiary of Merck & Co., Inc. All rights reserved. 5/16 BV-SG-55108

Consider Cow Condition After Weaning and Well Before Calving Minimal demands from a calf or fetus make mid-gestation a good time to adjust the condition of your cows. By Gary DiGiuseppe

Immediately after weaning, the beef cow is at the time of year when she has the lowest energy requirements. Her last calf is weaned and she is not lactating. Her next calf is still a fetus and making minimal nutritional demands on her. So, getting her the proper nutrition at this time is based on this factor: Is she in good enough shape to carry her calf to term and then rebreed on time, or does she need to build up her energy stores? Dr. Brandon Nuttelman, beef cattle technical services for Merck Animal Health, says if cows are in adequate body condition, they do not need to be fed a high energy diet. “However, if cows are in poor body condition and need to gain weight to obtain an optimal body condition score prior to calving, this is the time when the majority of the energy consumed by the cow will go toward body weight gain,” he says. Body condition score (BCS) is the best indicator of a cow’s energy status. There are multiple scales from different universities and researchers, but one of the most common scales goes

from 1 to 9, with 1 being extremely thin and 9 being extremely fat. “The target BCS for mature cows is a 5,” Nuttelman says. According to Texas A&M AgriLife Extension, you will not see the spine of a cow with a BCS of 5, but you may see 1 or 2 ribs. The cow’s hooks and pins are visible, her tailhead and brisket carry no fat and her muscling is full. “If you score the condition of your cows at weaning, this can serve as a guide to helping determine the cow’s nutritional needs for the next couple of months so she is prepared for calving. Once you determine the nutritional needs and a diet for the coming months, you can evaluate your plan by monitoring the change over time in the cow’s BCS,” Nuttelman says. To monitor gradual changes in the cow’s body condition, he says, observe the backbone and the hips of the cow. There are a number of technical bulletins on how to score the body condition of beef cattle. A change up or down 1 level in BCS is about 75 pounds, which can be tough to detect if you see your cattle every day.

8 Merck Animal Health BEEF CATTLE PRODUCTION SERIES – PART 7 thecattlemanmagazine.com

The biggest indicator of the cow’s energy status is her body condition score. “It is good to revisit a tech bulletin to make sure those cows are in the BCS you think they are, or have an Extension agent or a neighbor come out — somebody else with a ‘foreign eye’ — to look at your cows and give their opinion on the condition of your cows. This will help ensure that your cows are not losing too much condition before you realize it and it is too late.” The resources a rancher has play a large role in his or her ability to control the cow’s energy status. “When the calf is weaned off the cow, the energy requirements of that cow drop significantly,” Nuttelman says. “The dry cow will need 70 to 75 percent of the energy of a lactating cow. Therefore, she can maintain herself on a diet relatively low in energy for 2 to 3 months before the next calf is born. “If cows are being fed a partial or a complete diet on a daily basis, and they are in good body condition when their calves are weaned, you can decrease the amount of energy that they are fed by 25 percent. If cows are in a grazing situation, the quality of the forage at that time will determine whether the cow will change her BCS. Any excess energy beyond maintenance at this time will be stored as fat.” Nuttelman says that in some cases, adding weight to the cows is a good thing. “If the cow is in heavier condition going into calving, she has reserves and you can get by with a little

less energy in the diet before the cow loses too much body condition.” However, remember that having extremely fat cows at calving can lead to dystocia. It is important for producers to limit the amount of condition the cow loses postpartum. Nuttelman says it is very well documented that cows on an increasing plane of nutrition prior to breeding are more likely to get bred early in the breeding season than are cows on a decreasing plane of nutrition. Even if the BCS is sound at and after calving, the energy requirements cannot be ignored. The cow still needs to be maintaining or on an increasing plane of nutrition. If the cows have a low BCS, the easiest time to rebuild their energy stores is right after weaning, when their requirements are at their lowest. Whether you work with an Extension agent, nutritionist or use a computer yourself, Nuttelman says that some kind of feeding program can help you formulate a well-balanced diet to make sure that the required energy is available for the desired weight gain. “It doesn’t have to be an expensive diet. The cheaper the diet can be formulated, the better off the rancher is, as long as the cow’s nutrient requirements are met. The amount of energy required in the diet depends on how quickly you want to get those cows in better condition, and what your available resources are to accomplish this.” ➤

Table 1. Nutrient requirements of beef cows Net Energy Required Mcal/day Month since calving

Maintenance

Growth

Lactation

Pregnancy

Total

10.3

4.8

0.00

10.3

5.7

0.00

16.0

10.3

5.2

0.01

15.5

10.3

4.1

0.30

14.4

10.3

3.1

0.70

13.5

10.3

2.2

0.16

12.7

8.5

0.32

8.8

8.5

0.64

9.1

8.5

1.18

9.7

8.5

2.08

10.6

8.5

3.44

11.9

8.5

5.37

13.9

*Assumes an 1170 pound, two-year-old cow, calving March 1 with average milk production. Nutrient Requirements of Beef Cattle, 7th Revised Edition, 1996, National Academy Press, Washington, DC thecattlemanmagazine.com

Merck Animal Health BEEF CATTLE PRODUCTION SERIES – PART 7

If cows are in poor condition at weaning, the sooner they can start putting on body weight, the better. Although the changes in energy demand from day-to-day are minimal, each day the cow gets closer to calving, the greater are her requirements. It would be beneficial to evaluate your cows as close to weaning as possible, but still early enough to allow you time to have a plan in place to help her gain body condition as quickly as possible. Remember that 1 BCS is equal to 75 pounds of body weight. If you want your cattle to gain 1 BCS in 30 days, you will have to feed them to gain 2.5 pounds per day. Sorting strategy A potential management strategy would be to sort your cows into 2 groups after weaning so they can be managed according to their BCS. Sort the cows in poorer condition (i.e. BCS 4 or less) into a group to be fed a higher energy diet. The cows that are in proper BCS (i.e. 5 or greater) could be fed a lower energy diet, which is commonly a less expensive diet. This management practice depends on your ability to feed different diets efficiently to separate groups of cows. If a larger number of your mature cows need additional assistance following weaning to ensure they rebreed in the next breeding season, Nuttelman recommends evaluating your breeding management program. You can potentially manipulate this problem by adjusting your calving period to match your available resources more closely, or you may determine that your herd simply does not fit the current environment. The cow’s greatest energy requirement occurs during peak lactation, which is 60 days postpartum. She will also be trying to get rebred in order to calve within a 365-day window. Nuttelman says the cow’s energy requirements start to decrease after peak lactation as she starts producing less milk, and her calf starts to demand less milk as it begins to consume additional feed.

Third trimester needs higher energy and protein As the cow enters the start of her third trimester, energy and protein requirements begin increasing at a greater rate. Protein is commonly the first limiting nutrient once the cow enters her third trimester. However, this is entirely dependent on the diet the cow is consuming. As the fetus continues to grow and the cow prepares for lactation, energy requirements increase. These nutritional demands will continue to increase until the cow reaches peak lactation once again. At this point, the cycle begins again. “As far as the cow’s demands are concerned, mid-gestation is the best opportunity to manipulate her BCS, because this is typically when the cow is not lactating,” he says. Additionally, Nuttelman reminds producers that a cow should be on a balanced mineral program year-round, one that matches the time of the season for a specific region. The most expensive mineral is not necessarily the best or even necessary for an individual producer. Having a basic understanding of the cow’s mineral requirements for the specific area where she is living can help producers avoid spending money unnecessarily. Mineral supplementation is also a good method for incorporating an ionophore into the cow’s daily diet, which will help improve forage digestibility. It is important to remember that a cow needs to be in optimal body condition at the time of calving for her to wean a healthy calf and for her to be successful in the subsequent breeding season. If a cow is in poor condition and needs to gain additional weight, the easiest point in the energy cycle to accomplish this is when the calf is weaned and she becomes dry, which typically coincides with mid-gestation. Each operation has different resources available and, therefore, producers need to match the cow’s nutrient requirements with their resources. ❚

10 Merck Animal Health BEEF CATTLE PRODUCTION SERIES – PART 7 thecattlemanmagazine.com

Make Sure Second-Trimester Cows Get the Right Nutrition By Gary DiGiuseppe

The emerging science of fetal programming hopes to show how changes in the nutrition of a pregnant cow will affect the future performance of her soon-to-be-born calf, from quality of beef to reproductive capacity of females. A number of important discoveries have been made in a relatively short time. “It seems as though we should be able to do some things in the future in terms of muscle cell development and improved health,” says Dr. Wade Nichols, senior technical services manager at Merck Animal Health. “What is interesting is that we used to think that we could save a lot on our feed bill by cutting the cows back on their groceries in the second trimester. Their maintenance requirements are so much lower due to less milk production, and the fetus is not growing to any great degree during this time. They are really just maintaining. “We still can do that to some degree, but now when we talk about fetal programming, we find that during the second trimester we might want to feed those cows a bit better than what we did in the past.” Nichols continues, “If we provide a more adequate nutrition program to the cow, we affect how the genes of the fetus perform, so later in life, the calf that received optimum nutrition through its gestation period is able to develop more muscle thecattlemanmagazine.com

cells and more fat cells in terms of marbling or intramuscular fat. In addition, it has a health advantage over that of an animal without adequate nutrition. Recent research has indicated the genes are the same, but adequate nutrition during different stages of the gestation period can affect how those genes express themselves.” Research finds that an increase in vascular development of the maternal attachment to the placenta begins at day 90, with a marked increase in blood flow and vascular density by day 120. That is the start of the second trimester, and any detrimental effects of maternal nutrition during that time would impact the ability of the fetus to acquire proper amounts of nutrients and oxygen. This, in turn, can contribute to liver enlargement, reduced muscle growth, thickening of heart walls, hypertension, and insulin resistance in calves as young as 8 months of age. When the fetus has insufficient nutrients, it will direct nutrients to essential organs, like the heart and brain, and away from muscle and fat. Animals are born with a set number of muscle cells (hyperplasia), and can only increase their muscle mass after birth by increasing the size of each individual muscle cell (hypertrophy). Fat cells are also primarily laid down during gestation, and only increase in size after birth. Calves that do not receive Merck Animal Health BEEF CATTLE PRODUCTION SERIES – PART 7

adequate nutrition in utero will have less muscle and less marbling than will calves whose dams received adequate nutrition, according to Dr. Steve Paisley at the University of Wyoming. The third and final trimester is still when the cow needs the greatest boost to her nutrition. The fetus is growing to its greatest extent, achieving 90 percent of its birth size. The cow also needs nutrition stores to commence full lactation when the calf is on the ground and then to be ready to rebreed a very short time later. This means the cow has to have achieved a good body condition score (BCS) at the point of calving. Nichols says, “Coming into the third trimester, before the cow calves, we want to have a BCS between 5 and 6. We want heifers to be between 5.5 and 6.5, so they carry enough condition coming into the breeding season to rebreed.” The heifer, of course, is still below her mature weight. Nichols says that during her third trimester she needs to be gaining at a rate of 2 to 2.5 pounds a day. “The heifer is going to calve at 70 to 80 percent of her mature weight,” he notes. “She is still a baby and has to keep growing while she grows that fetus, then calves and breeds back. Her nutrition requirement is much, much higher than that of a cow.” Balanced, optimum nutrition during third trimester This means that the producer has to improve the cow’s nutrition from the second to the third trimester with balanced and optimum nutrition programs. A 1,200-pound cow is going to need about 2 pounds of protein in her third trimester because the protein will be required by the fetus and the placenta. She is going to consume about 25 pounds of dry matter, which should be in the range of 55 percent total digestible nutrients (TDN). The best way to raise the cow’s nutritional plane is to evaluate her feed. Nichols says a ruminant can get by on a moderately good forage base, but it has to have at least 8 to 9 percent protein in it to keep the rumen microbial population viable and digesting the forage. Nichols encourages ranchers to test their forage. “If it is low in protein and the cows are out of condition, you can add a protein supplement or a grain supplement. It all depends on the BCS.” This issue is one of nutritional quality because while the second-trimester cow will eat just as much as the third-trimester cow, she does not need as much in terms of nutrition, due to different maintenance requirements. Therefore, optimum nutrition programs need to be developed to meet the cow’s nutritional requirements at each stage of gestation. Nichols says, “As we have iterated, the second trimester is still important and we want to meet the requirements in terms of nutrient density and dry matter intake. In the third trimester, the cow increases her requirements and we need to provide a

BODY CONDITION SCORECARD 1. EMACIATED: Starving and weak. No palpable fat detectable over back, hipbones or ribs. Tail-head and ribs project quite prominently. 2. POOR: Poor milk production and reproduction. Chances of rebreeding slim. Cow still emaciated but tail-head and ribs are less prominent. Backbone is still rather sharp to the touch but some tissue exists along the backbone. 3. THIN: Poor milk production and reproduction. Ribs are still individually identifiable but not quite as sharp to the touch. There is obvious palpable fat along the spine and over the tail-head, with some tissue over the top portion of the ribs. 4. BORDERLINE: Reproduction bordering on inadequate. Individual ribs are no longer visually obvious. Individual spines can be identified on palpation, but feel rounded rather than sharp. There is some fat cover over ribs and hipbones. 5. MODERATE: Minimum necessary for efficient rebreeding and good milk production. The cow has a generally good overall appearance. Upon palpation, the fat cover over the ribs feels spongy, and the area on either side of tail-head now has a palpable fat cover. 6. OPTIMUM: Milk production and rebreeding are very acceptable. Firm pressure now has to be applied to feel spinous processes. A high degree of fat is palpable over ribs and around tail-head. 7. GOOD: Maximum condition needed for efficient reproduction. The cow appears fleshy and carries obvious, considerable fat, with a very spongy fat cover over the ribs and around the tail-head. There is some fat around the vulva and crotch. 8. FAT: Very fleshy, no advantage in having cow this condition. The backbone is almost impossible to palpate. The cow has larger fat deposits over her ribs, around the tail-head and below the vulva. 9. EXTREMELY FAT: The fat may cause calving problems. The cow is extremely wasty and patchy. The tail-head and hips are buried in fatty tissue. The bone structure is no longer visible and barely palpable. The animal’s mobility maybe impaired by fat deposits.

12 Merck Animal Health BEEF CATTLE PRODUCTION SERIES – PART 7 thecattlemanmagazine.com

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THE SATISFACTION OF A JOB WELL DONE IS ITS OWN REWARD.

Better performance and higher value for every calf is even more satisfying. From birth to sale day, a PrimeVAC™ preconditioning program can turn healthier calves and higher weaning weights into real value for you and your customers.

To find the PrimeVAC preconditioning program that’s right for your operation, talk to your veterinarian and visit cattleprimevac.com. Always consult your veterinarian concerning: best health management decisions specific to your operation, selection of qualified USDA/FDA approved products, optimum use of combination products, and the efficacy of vaccination in the face of maternal antibodies. Always read, understand, and follow product label and use as directed. Data on file. merck-animal-health-usa.com • 800-521-5767 Copyright © 2016 Intervet Inc., doing business as Merck Animal Health, a subsidiary of Merck & Co., Inc. All rights reserved. 54670 1/16 BV-PV-51322

higher quality diet that meets the dry matter intake of the cow. The third-stage nutrition program might utilize supplements and more densely packed nutrient feedstuffs to meet those requirements.”

a malnourished cow, while it will not slough the fetus, does have the potential to raise a calf with what is known as “weak calf syndrome.” That calf will have the propensity for more problems with its health and will not grow as well as its cohorts.

Clues to gauging body condition score According to a Texas A&M AgriLife fact sheet, generally only the 12th and the 13th ribs are distinguishable on a cow with a BCS score of 5. The muscle tissue is close to maximum and the fat deposit behind the shoulder is noticeable. For a score of 6, the ribs are covered completely and fat is beginning to cover the rump; the ribcage is barely visible and muscle tissue is at its greatest. For a score of 7, the ribs are not visible, skeletal structures are becoming difficult to identify and there are fat deposits under the udder and behind the shoulders. With lower, thinner grades, bony structures like the spine, ribs, and the hooks and pins are fully visible. For those animals, Nichols says, “If I want to tailor my nutrition program for the cows that are in BCS 1 to 4 and I have a facility, I will put them in a place where I can feed them and give them the energy and protein that they need to gain weight.” The cows that are in BCS grades 5 to 7 will just be maintained, and those above 7 will be isolated and fed a diet that might help them return to a body condition score of 5 to 6. He says, “We can cheapen the diet for these cows and save a little money. You do not want to starve them; you just want them to lose a little weight.” Even a gaunt cow, he notes, will continue to support the calf growing inside her. She would have to be far down the road of malnutrition for her nutritional state to threaten the fetus. However,

Provide the right nutrition early Do not wait until the cow approaches calving to adjust her nutrition program. Nichols says that you are much too late if you wait until that time to get her to the correct nutritional plane for lactation and rebreeding. To achieve the desired goal of bringing all the cows to the BCS appropriate for the tasks ahead — programming the fetus, adequate resources that support lactation and rebreeding — the nutrition plan needs to start 60 to 90 days beforehand. He says, “Once they are lactating, they are going to start ‘moving a lot of fat off the back,’ mobilizing a lot of fat to maintain some of that lactation. So you need to have them in good condition before they calve.” You can put cows together for calving purposes unless there are some so far out of condition that they have to remain on a more intensive feeding program. The gestation period of cows is about 281 days, so the producer has about 60 to 80 days after calving to get them rebred. If the cow is drawing most of the energy required for lactation off her own fat reserves, it will affect her likelihood of returning to a reproductive state where she rebreeds on time.

Get ready for calving Nichols says that as the date approaches, “Make sure everything is ready for calving. You want your heifers to calve away from your cows if possible (heifers will generally be bred to start calving about 30 to 45 days before the herd, as this gives them more time to rebreed with calving dates close to the rest of the herd). Get ready for that, so you can move cows off the calving ground onto another pasture. This helps reduce disease transmission and spread. “Have all your calving tools ready. Make sure your vaccination program is up-to-date. For enteric diseases like scours, we want to start the vaccines 2 to 5 weeks prior to calving so the antibodies to help prevent disease will be passed to the calf through the colostrum. “I hope your cows will be on a vaccination program, pre-breeding and through the Fetal Development Timeline breeding season, and then prior to calving,” Adapted from Washington State University: EM060E: Feeding Beef Cattle II: Fetal Nichols says. ❚ Programming & Rethinking Cow/Calf Feeding Programs

14 Merck Animal Health BEEF CATTLE PRODUCTION SERIES – PART 7 thecattlemanmagazine.com

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