FOCUS ON CALVES Technical advice for rearing healthy calves
e ph by Alic Photogra
Photogra ph by M egan Sm ith
Staggs
Photograph by Carys Dyke
wynnstay.co.uk 1
MEET THE CALF & YOUNGSTOCK TEAM Millie Hendy
Jess Yeomans
Senior Calf & Youngstock Specialist South West and Midlands
Senior and Technical Calf & Youngstock Specialist Shropshire, Cheshire, Herefordshire, Worcestershire and N. Wales
m: 07717 495746 e: millie.hendy@wynnstay.co.uk
m: 07990 584740 e: jess.yeomans@wynnstay.co.uk
@hendycalf1
@charltoncalf1
Hannah Padfield
Calf & Youngstock Specialist South West, Somerset, Dorset, Hampshire and West Sussex
Laura Monk
Calf & Youngstock Specialist Cornwall, Devon, Dorset and Somerset
m: 07968 260110 e: hannah.padfield@wynnstay.co.uk
m: 07767 275662 e: laura.monk@wynnstay.co.uk
@padfieldcalf1
@monkcalf1
Elinor Thomas
Hannah Braithwaite
Calf & Youngstock Specialist Mid & South Wales
Calf & Youngstock Specialist Shropshire, Cheshire, Herefordshire, Worcestershire and N. Wales
m: 07500 979398 e: elinor.thomas@wynnstay.co.uk
m: 07881 093633 e: hannah.braithwaite@wynnstay.co.uk
@thomascalf1
@hannahcalf1
Kim Carnegie
Trainee Calf & Youngstock Specialist Lancashire and Cumbria
m: 07718 773035 e: kim.carnegie@wynnstay.co.uk @KimCarnegie3
Key Elinor Millie Hannah P Hannah B Jess Laura
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INTRODUCTION Welcome to our 9th edition of the Focus on Calves. We would like to congratulate Jess Yeomans who returns to work after the arrival of twin boys and introduce both Hannah Padfield and Kim Carnegie, who join the calf and youngstock team covering the South West and the North of England respectively. We also wish a fond farewell to Eimear Diamond, who has decided to return home to Northern Ireland.
Global milk supply has tightened significantly, with only China and South America increasing their production over the last year or so. Both skim and whey prices remain reasonably stable, however, the outlook is still uncertain with the majority of farmers not pushing for increased yields when the cost of inputs such as; energy, feed, fertiliser and labour are all rising so quickly.
In the wake of the pandemic and the current war in Ukraine, we can only describe our present marketplace as volatile. Combined with a shortage of raw materials, I believe we have seen a shift in customers’ focus on return on investments and streamlining business operations.
In this publication, we take you on a journey through all aspects of calf rearing, a gentle reminder that all stages need to work in harmony to ensure a successful and profitable enterprise. Elinor discusses NRC changes, as these are the first we have seen in 11 years! We also look at disease, with Laura Monk focussing on Clostridial disease, Hannah Batty giving tips on preventing salmonella in calves and Jess Yeomans sharing Housing and Hydration considerations. In May, we ran a competition for our customers to participate in this issue by taking pictures on farm. The winning photos are featured on the cover and within this publication. Thank you to everyone who sent their images in, we loved seeing them and we hope you do too!
Millie Hendy
Senior Calf & Youngstock Specialist South West and Midlands
m: 07717 495746 e: millie.hendy@wynnstay.co.uk
@hendycalf1
Photograph by Tracey Evans
CONTENTS 2:
Calf & Youngstock Team Contacts
16: Cow Nutrition Is Critical To Calving Success
3:
Introduction & Contents
4:
Wynngold & Calf Milks
17: Offset Housing Challenges With Attention To Detail
5:
Start ‘n’ Wean
6:
Calf Housing Considerations
8:
Optimising Calf Milk Replacer
18: Reduce The Incidence And Consequences Of Dehydration In Calves 20: Salmonella - Spot It, Stop It! 21: Route of Transmission of Bovine Terbuculosis
10: Managing Rumen Development on A High Fat Milk Replacer
22: Postbiotics - A Game-Changer In Calf Health 24: Beating Coccidiosis – What’s the Best Way?
11: Understanding The True Cost Of Pasteurisation
25: Clostridial Diseases In Dairy Calves
12: Change Is Coming For Our Calves
26: Lifetime Impact Of Preweaning Nutrient Supply In Dairy Calves
13: Stress Affecting Daily Liveweight Gain 14: Bodyweight And Age Of First Calving… It’s A Balancing Act
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FOCUS ON CALVES 2022
20%
23%
18%
22%
20%
23%
18%
22%
17%
26%
Oil
Protein
Oil
Protein
Oil
Protein
Oil
Protein
Oil
Protein
& CALF MILKS • Made using the highest quality ingredients • A variety of formulations to meet different rearing objectives • Nutritionally balanced to meet the demands in the first few weeks of life • Sustainable and responsibly sourced raw materials • Free from soya • Manufactured in Britain
20%
23%
19%
21%
Oil
Protein
Oil
Protein
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25%
23%
Oil
Protein
27%
23%
Oil
Protein 50% Skim 100% Dairy Protein
20%
27%
19%
20%
Oil
Protein
Oil
Protein
START ‘N’ WEAN Youngstock are the future of your herd, so optimising their growth and development is the key to future profitability. Start ‘n’ Wean is specifically formulated to set up a healthy rumen by three months of age.
A good calf starter ration should have following elements: • • • • • • • •
Attractive smell Palatable Highly digestible Optimum levels of starch Natural sugars High level of undegradable protein Balanced vitamins and minerals Effective health pack
health pack unique to Wynnstay A combination of rumen specific live yeast, very high levels of Mannan Oligosaccharide (MOS) and essential minerals and vitamins • The combination of a probiotic and prebiotic has been chosen to optimise rumen development as well as help protect the lower gut • Significantly increases average daily gain and feed conversion ratio • Improves weaning success by ensuring a smoother, safer transition to solid feed
Hipro Soya - highly digestible protein source, essential for growth
Sugar Beet Pulp, Molasses - natural sugars help growth of a healthy bacteria population to digest concentrate efficiently
Maize, wheat and barley - release starch at variable rates
which is digested to create volatile fatty acids. These organic acids stimulate the growth of rumen papillae which grow longer in this healthy environment
Nutritionally improved straw (NIS) - slows fermentation,
START ‘N’ WEAN
prevents acid peaks and enables the rumen to extract more nutrients. Increased intakes and improved daily liveweight gains
Start ‘n’ Wean is available from your Wynnstay Calf & Youngstock Specialist, Wynnstay Representative or your local depot
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FOCUS ON CALVES 2022
CALF HOUSING CONSIDERATIONS
Problemsincalfbuildingsusuallyareduetoimbalancesinoneormoreofthesefivesepara factors;Moisture,FreshAir,AirSpeed,TemperatureandHygiene. 1. Moisture (Too much)
3. Air speed. Too much and too little
Too much moisture supports microbial activity and promotes bacterial growth in some species. Moisture also absorbs energy which is often a limiting factor to calf health and growth. Lying liquid also acts as a transport medium making it easier to spread disease around a calf unit, as well as potentially increasing stress from causing slippery floors. This will contribute to increased straw usage; with increasing costs, waste should be minimised. When it comes to indicators of too much moisture in calf housing frequently seen would be- standing dirty water, damp floors in areas that could be dry, condensation, staining or mold growth of the underside of the roof and dirty cattle (particularly the knees and back legs).
Too much air speed (draught) is often associated with excessive energy losses. A calves lower critical temperature is 15°C and if this is exasperated with a draught a young calf can become chilled extremely quickly. Calves in a draught will often display a hairy coat, have high intakes but low production outputs (DLWG) and may tend to huddle together to keep warm or avoid certain areas of the shed altogether. Calves in smaller pens may not have the luxury of being able to move away from the draught, therefore every pen must be looked at carefully to ensure no pens are directly in a a draught. Too little airspeed will result in animals avoiding certain areas of the shed, there will be a smell/ammonia build up and animal health could become sub optimum.
Solutions The most important factor to reducing excess moisture is to have proper waste management, which includes a fall on the floor. The fall of the floor should be 1 in 20 below straw. For this reason other forms of flooring aren’t generally recommended due to not being able to thoroughly cleaned. The fall should then lead to drainage within the pen to avoid wet areas outside the pen. Drainage should also be between pens, within the building and outside too. Manure and waste straw management should be done effectively away from the calves as much as possible. Providing good gutters and downpipes around the building to avoid any excess rainwater entering the calf building is also greatly important. Having air inlets and outlets will help to provide a dryer atmosphere.
Solutions Provide good air inlets and outlets. Protection from the wind above animal height should also be provided and consider more use of perforated wall cladding and aim to eliminate draughts at animal height. Air inlets and outlets a simple assessment of the building will help to establish good air inlets and outlets. 1. assess the roof first. no outlets= guaranteed contribution to problems 2. area of opening in roof a. depends if: slope of the roof and energy density within the building (Flat roof=bad:>17 degree slope=good. b. Outlet areas in the ridge: 0.04m2 per calf and 0.1m2 per adult.
CALF HOUSING CONSIDERATIONS
2. Fresh Air (Too Little) Lack of fresh air in calf housing increases survival time of airborne pathogens and increases the concentration of gaseous emissions and reduces oxygen concentrations, which can reduce the effectiveness of the respiratory tract defences. A calf building with not enough fresh air will smell of ammonia and dampness and generally have a warmer air temperature and inevitably dark damp corners. Solution
3.
Area of inlet need to be approximately at least twice (ideally x4) the area of the outlet.
4.
Design of inlet: a. Always looks to eliminate draughts at animal height
Encourage fresh air to enter the shed. 100% fresh air kills airborne bugs 10x quicker than 50% fresh air. To encourage increased fresh air in calf buildings the use of air inlets and outlets should be considered. It is important to note that calf housing will not have any stack effect.
b. Large openings increase air speed, so try to diffuse using space boards, Yorkshire boards or weave mesh type products.
All calf housing (unless Igloos, or HHU) needs a fan and a duct.
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When considering altering, updating or installing new calf housing taking into account these 5 factors that have a huge influence in the successfulness of the calf housing will hopefully enable a better environment for young calves. Photograph by Alice Staggs
4. Temperature
5. Hygiene
The lower critical temperature for calves in the first week of life is 15°C. Therefore for many months of the year new born and young calves are born into an environment where they are cold stressed. This combined with the poor thermal properties of calf housing such as dampness, tin roof, concrete walls and the fact that often there is no energy in a calf shed to drive the stack effect results in calves that are using more energy to keep warm rather than proportioning energy to fighting disease of growth.
Hygiene within the calf shed should be of upmost importance and an inadequate hygiene protocol will mean reoccurrence and spread of potentially deadly pathogens. An unhygienic environment will result in a calf not meeting performance targets and a high disease morbidity rate. Poor hygiene often manifests itself in a high rate of scours, joint illness and respiratory disease.
A rigorous hygiene and disinfection programme can help to minimise disease outbreaks. Making the calf building easy to clean will mean a more successful procedure and it is more likely to get some to an acceptable standard. Removing the biofilm, allowing pens to have the minimum recommended contact time for the disinfectant and through drying time are key elements to the best practice for hygiene. The use of heat, UV and steam are also recommended. but perhaps the simplest of all is time. Give the pens/ equipment time to rest if possible between calves or groups of calves.
Solution In calf housing the use of stock boarding/plastic cladding and sheeted gates should be massively encouraged. Not only is stock board more hygienic and easier to clean when a calf rests against it energy isn’t being leached out into the concrete but maintained within the calf. Ensuring the calf environment is dry and well bedded by regularly checking water troughs and providing adequate drainage will help to minimise cold stress. Using a Wisconsin nest score is a useful tool to help identify if bedding down is completed sufficiently for the time of year.
Jess Yeomans
Senior and Technical Calf & Youngstock Specialist Shropshire, Cheshire, Herefordshire, Worcestershire and N. Wales
m: 07990 584740 e: jess.yeomans@wynnstay.co.uk @charltoncalf1
Photographed by Sarah Griffiths
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FOCUS ON CALVES 2022
CALF HOUSING CONSIDERATIONS
Solution
OPTIMISING CALF MILK REPLACER Introduction Over the past year dairy commodity markets have shown unprecedented volatility, and we have experienced some ingredients, such as skimmed milk powder and sweet whey powder, reaching historically high levels. This coupled with increasing vegetable oil prices mean that the cost of calf milk replacer (CMR) has continued to rise, which inevitably adds cost to calf rearing systems.
Supporting Calf Performance The balance between digestible energy and high-quality protein sources provides the nutrients required for calves to achieve performance targets. When reviewing calf milk replacer specification and feed curves it is important to consider nutrient intake alongside associated costs. For example, moving from a high specification product may reduce cost per litre or cost per calf per day, however the calf feeding period may need to be extended to achieve target weaning weights.
When reviewing feeding strategies to try and optimise performance and/or manage costs, it is important that we consider the short- and longer-term impacts of changes. For example, it is important to consider the cost associated with preweaning nutrition alongside other costs encountered during the calf and heifer rearing period; for example the impact, consequences and associated costs of health incidences such as scour, or the financial implications of missed growth targets for insemination or calving down.
We should not forget that the environmental factors and health pressures, which can vary on each unit, are a crucial consideration. For example, a unit may be achieving low treatment or mortality rates due to the supportive nature of the nutritional strategy, alongside the expert advice from the vet team. If this nutritional strategy is reduced, this can often result in an increase in associated problems arising which in turn can add cost such as veterinary and medicine support, staff labour looking after unwell calves and/or prolonged milk feeding period.
OPTIMISING CALF MILK REPLACER
Ask questions to understand specifications There is significant variation in CMR specifications available in the market, this ensures that there is a product available to match the objectives and required price point of different calf rearing systems. Due to the investment, careful consideration should be taken when deciding on type of CMR and appropriate feeding scheme on farm – working with your nutritionist, calf specialist and vet will ensure all information can be collected and considered in order to support an informed decision.
It is also important to consider the weaning challenge supporting adequate performance at weaning is crucial to support robustness and resilience of calves for upcoming changes that can underpin periods of stress e.g. group changes, housing changes, diet changes. So, in summary, it is important that we consider the cost associated with nutrient intake. We can achieve a reduction in the price of the CMR, however if we are reducing the energy and protein intake to the calf, or the nutrient digestibility, then calf performance (DLWG and/or health) can be affected.
With the increased price of raw materials, it may be suggested that changing CMR product to a cheaper powder may achieve a cost saving per tonne and offer a quick solution to save money. However, it is important to understand how the specifications differ in order to consider the implications that the change may have on practical feeding, calf performance and health as well as long term animal performance. The price of CMR (£/tonne) can be reduced in a number of different ways, including: • •
•
Reducing energy content or digestibility – normally through reducing oil levels, this can lead to an increased lactose level and therefore will affect overall osmolality Reducing protein level or protein digestibility – dairy protein sources are increasing in price so including, or increasing the inclusion, of vegetable sources help to reduce cost. However be mindful of digestibility differences Reduction or replacement of skimmed milk or whey products, with alternative whey derivatives or lower quality milk-based ingredients
Photograph by Sarah Griffiths
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OPTIMISING CALF MILK REPLACER Drainage and ventilation should not be forgotten, all calf units are unique and some therefore experience different pressure points. When reviewing nutritional strategies, the implications on environmental challenges should be remembered. Increasing volume to match nutrient intake, may lead to an increase in shed humidity if drainage is a pinch point.
Implications on practical feeding If we are changing the nutrient makeup of the CMR we are feeding it is important to be mindful of the considerations around practical feeding. Changing specifications or formulations may affect solubility and physicality of the mixed milk. A change in digestibility or osmolality of the overall liquid feed may require the feed curve to be tweaked. For example, concentrations may need to be lowered to control the osmolality of the liquid feed and volumes may need to be reviewed to take into account overall nutrient intake. In some instances, target volumes and speed of volume increase along the feed curve may need to be considered. Recent research has demonstrated that calves regulate their intake of milk replacer based on energy density. It has been shown that calves fed milk replacer where lactose was exchanged for fat exhibited less signs of hunger during weaning which may reduce weaning stress.
On many units it may also be worth reviewing the complete calf rearing strategy. Objectives for rearing replacement heifers and beef calves can be very different therefore considering a change in feeding protocol to different groups can offer a cost saving solution. Measure and monitor key performance indicators Monitoring and managing key performance indicators (KPIs) is essential, if we understand our current performance it allows us to understand the changes that may offer us opportunities to ensure we are being efficient.
Table 1: Overview of calf key performance indicators
Calf Key Performance Indicators Average Daily Liveweight Gain (DLWG)
g/h/d
>800g, maximising early life growth rates has shown multiplebenefits
Weaning weight
Minimumoftriplebirthweight,ifbeingachievedaimfor
4 weeks post weaning weight
>2kg/calf/dayforthreeconsecutivedays
Start feed intakes at weaning
*perhapsrefertomortalityratesandreferencecalfheal planwithvet?
Health incidences/treatment rates
5-60%ofBWforinsemination
Heifer development
85-90%ofBWforfirstcalving
Age at first calving
2-4months
The calf rearing period offers a unique opportunity to capture the potential of enhanced feed conversion efficiency whilst also exploiting the genetic potential of the animal. DLWG will continue to an important metric, however widening the scope with regards to objectives to consider optimal development, resilience to disease and longevity allows us to take calf rearing to the next level.
LifeStart Science research by Trouw Nutrition has shown that elevating the plane of nutrition pre-weaning not only leads to higher calf growth rates and improved heifer performance. In addition, the latest research demonstrates clear long-term benefits on fertility, survivability and lactation performance providing a clear return on investment.
Georgina Thomas
Young Animal Feed Manager GB Regional Manager Milkivit
Trouw Nutrition GB
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FOCUS ON CALVES 2022
OPTIMISING CALF MILK REPLACER
3.25
MANAGING RUMEN DEVELOPMENT ON A HIGH FAT MILK REPLACER
What do we consider to be a high fat milk replacer? Current milk powders in the mark rangefrom17–27%oil,anythingabove20%canbeconsideredanelevatedlevel. The benefits of feeding a high fat milk replacer:
As the calf grows its maintenance energy requirement increases. During the first three weeks of life this requirement must be met by liquid feed because the rumen is not yet capable of fermentation. With the calf’s size restricting its daily intakes the only way to increase both growth and resilience is to increase the amount of energy fed per litre of milk.
1. Additional energy, for every 5% increase in oil the energy density of the powder is increased by 6%. 2. Reduced scours, energy in milk replacer comes from either fat or carbohydrate (oil or lactose), high fat milk replacers have lower lactose, naturally lowering their osmolality and reducing incidence of scour.
After three weeks starter feed comes into play albeit in small amounts, where the calf is meeting its energy requirements with its milk feeds starter feed intake will be reduced. Although as you can see in the table below as the calf’s bodyweight dictates a greater energy requirement and milk feeds are reduced to initiate weaning starter feed consumption comes into line.
MANAGING RUMEN DEVELOPMENT ON A HIGH FAT MILK REPLACER
3. Improved resilience, during periods of stress, disease challenge or low temperatures the calf’s energy requirement increases. Calves have very little body fat stored and rely on a constant supply of energy meaning increased requirements are more easily met with a high fat milk replacer.
Table A, below, compares the starter feed requirements of a calf on a 17% oil powder vs. a calf on a 25% oil powder, both containing 23% protein. The starter feed is a 12.4MJ/ kg DM nut and the following amounts are set to achieve 0.8kg/day growth.
A study conducted in 2021 looked at the behaviour and performance differences seen in calves offered either a high fat milk replacer (23% Protein, 23% Oil) or a high lactose milk replacer (23% Protein, 17% Oil) ad-lib for the first 35 days. During this ad-lib phase the high lactose group consumed more milk than the high fat group but energy intake and performance remained the same. This study shows that a calf will manage their own intakes to meet their energy requirements.
To conclude, providing more energy via milk feeding facilitates growth and resilience in early life where challenges tend to be at their highest. The digestibility of milk replacer also outweighs that of starter feed in the first 4 – 6 weeks. Where milk replacer feeding is elevated above 6L on high energy powders weaning needs to be considered more carefully as starter feed intake will be delayed, but as with all feed plans stepping down the milk and achieving starter intakes of 2kg/day on a 12MJ/kg DM or above starter feed before milk feeding is withdrawn completely will maintain growth rates.
The benefits of using a high energy milk replacer are numerous but does providing extra energy in the liquid feed prevent high intakes of starter feed from driving rumen development?
Grams of starter feed/day
Calf Age
Milk fed/day
Calf Weight
17% Oil Powder
25% Oil Powder
21days
6litres
5kg
250g
125g
28days
6litres
60kg
325g
20g
35days
6litres
6kg
40g
300g
42days
5litres
72kg
700g
60g
47days
4litres
76kg
900g
1,000g
50days
3 litres
79kg
1,20g
1,300g
53days
2litres
82kg
1,50g
1,50g
56days
0 litres
84kg
2,0g
2,0g
Table A
Laura Monk
Calf & Youngstock Specialist Cornwall, Devon, Dorset and Somerset
m: 07767 275662 e: laura.monk@wynnstay.co.uk @monkcalf1
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UNDERSTANDING THE TRUE COST OF PASTEURISATION
Withrisingcostsofproduction,includingenergy,waterandmilkreplacer,farmers temptedtolookforpotentialsavingswhenitcomestofeedingcalves.
What is pasteurisation? Pasteurisation was first developed by Louis Pasteur who proved that microbes responsible for food spoilage could be avoided through elevating temperature to 63°C (145°F) for 30 minutes or 72°C (162°F) for 15 seconds. This heating process improved food safety and lengthened the shelf life of food with no changes in product quality and only minimal changes to vitamin content. Under ideal conditions, pasteurisation reduces the bacteria population by 99.999%. In other words, if one started with 100,000 bacteria, pasteurization would reduce this population to just 1 bacterium. As a result, pasteurisation rapidly became common practice, and even law, in the food systems of many countries. What/When to Pasteurise? Pasteurisation has gained traction in the dairy industry with several pasteurisers on the market to reduce bacteria levels in waste and whole milk fed to calves. Many farms have nonsaleable milk or waste milk in the form of transition milk, mastitis milk, and antibiotic-containing milk. Use of this milk as a source of liquid feed for calves can be a cost-effective way for farms to utilise otherwise unsaleable milk. However, raw waste milk may have very high bacterial populations depending on a number of factors: •
Animal from which the milk was produced
•
Cleanliness of how the milk was harvested
•
Time and conditions under which it was stored
Studies show that raw waste milk fed to calves has highly variable bacteria counts of up to a billion bacterial colonies per mL. High bacterial populations have been linked to diarrhoea and poor weight gains in calves. With proper pasteurisation and handling of liquid feed, calf exposure to high bacterial populations is greatly reduced, resulting in lower rates of illness and death with improved weight gains.
Before placing blame on the pasteuriser for not operating properly, it is important to review the entire processing procedure from collection of raw waste milk to delivery of the pasteurised milk to the calves. Pasteurising a poor product will not make it better and is not a good feed option for calves. Costs to consider Pasteurising whole milk has a range of costs which should be factored in. -Machine As discussed earlier, several machines are available. Which machine to chose will mostly be dependant on how much milk you want to pasteurise at a time. The most popular models are available in 100, 150, 260 & 400L capacity. These will feed 20-80 calves in one batch. A rough guide to purchase costs would be £6,200 £10,500. A few grants are available throughout the year which often have pasteurisers on. -Colostrum Having made the decision to pasteurise, it makes sense that all milk which a calf receives is pasteurised. Colostrum is higher in fat than whole milk, and cannot be batch pasteurised directly against the element as whole milk can. A separate machine may be needed to safely pasteurise colostrum to avoid destroying antibodies. -Time Labour and timings need to be considered. Pasteurisers need to be empty, clean, and disinfected by the end of milking, ready to start pasteurisation cycle. Total cycle time for 100L to get to temperature, pasteurise, and cool to feeding temperature is 2hours 30 minutes. Consider when this milk will be fed. Bacteria will double every 20 minutes at room temperature. -Electricity 100L pasteurised Heating time of the 2 hours 30 min cycle is 75 minutes. Average cost electricity per kWh (April 22) £0.28 28p/60mins= 0.0043p/min x75 mins = 32.5p / kW Assuming 5kW pasteuriser. Cost= 32.5px5
Ultimately, clean, warm, pasteurised whole milk is the gold standard of feeding for calves, however there are several 100% dairy protein milk replacers which will match this level of nutrition for calves. If cost saving is your motivation for feeding whole milk, the price of pasteurisation should be factored in. Saving pennies by feeding whole milk unpasteurised is risky, and costly in the long run.
Kim Carnegie
Trainee Calf & Youngstock Specialist Lancashire and Cumbria
m: 07718 773035 e: kim.carnegie@wynnstay.co.uk @KimCarnegie3
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FOCUS ON CALVES 2022
UNDERSTANDING THE TRUE COST OF PASTEURISATION
Whether finding yourself in the position considering moving from milk replacer to whole milk, or rethinking how you feed whole milk, pasteurisation must be explored.
CHANGE IS COMING FOR OUR CALVES “Ifyoualwaysdowhatyou’vealwaysdone,you’llalwaysgetwhatyou’vealwaysgot.” –HenryFord We have long waited for the eighth edition of the calf feeding recommendation and low and behold we have it. For the past 20 years we’ve been guided by the same nutritional recommendations for raising calves. Finally, we now have new guidelines to better steer our calf nutrition decisions. The last edition of the publication has served the dairy industry well, but there were inaccuracies in the prediction of calf growth. In the previous edition predicted calf gains were greater than observed in carefully controlled research studies. For the newest edition, they have completely new prediction equations based on recently conducted experiments with Holstein and Jersey calves. Those studies measured the actual body chemical composition of calves so that we could predict the energy, protein, and fat contents of body weight gain from dietary energy and protein The changes Energy needs
CHANGE IS COMING FOR OUR CALVES
A change for this edition is that maintenance requirements were raised for calves during both cold stress and heat stress. Requirements were set the same for Holsteins and Jerseys when corrected for bodyweight, because there was not enough research data to develop different equations based on breed. The table below gives us an idea of what the predicted average daily gain (ADG) was in the current and the previous edition. The new NRC edition predicts about 100 grams less body weight gain than the previous model and is closer to actual bodyweight gains. (Drackley, 2022)
This data is designed for pre and post weaned calves up to 18% of their mature body weight. the model for growing heifers should be used. Holsteins = 125kg (MBW = 698kg) Jerseys = 95kg (MBW = 528KG) Starter intake The new edition equations for starter intake consider the calf’s bodyweight, the amount of ME supplied by milk or milk replacer, and the age of the calf relative to when it was first offered starter. Farmers can estimate starter intake if they do not know the intake of their calves. Minerals Minerals matter, and this is one of the biggest changes in the newest edition. Calculating the mineral requirements has resulted in the below. • Calcium is lower for milk replacer but similar for starter and grower compared with the previous edition. • Phosphorus is about 15% lower for all feeds. • Potassium concentration is about 70% greater for milk replacer but similar for starter and grower. • Copper is about half of the previous values. • Iron is about 15% lower for milk replacer but similar for starter and grower. • Manganese is higher for milk replacer but similar for starter and grower. • Finally, zinc is about 40% greater than the previous edition.
Protein Protein requirements were changed to be presented as metabolizable energy (ME) instead of digestible protein in the previous edition. The protein requirement stays similar to the previous edition this model says that for every calf gaining 0.9kg DLWG the milk replacer should contain 25% crude protein, this would be comparable to the protein in cow’s milk on a dry matter basis.
Conclusion Since the previous calf feeding recommendation edition and based on the recent and extensive amount of research on growth and behaviour of young calves fed larger quantities of milk it is now recommended by the NRC that the minimum amount of milk or milk replacer solids that should be fed is 1.5% of birth body weight under thermoneutral conditions. The NRC also show the benefits of feeding more milk than that and encourages calf rearers to consider doing so.
Comparison of actual mean average daily grain (ADG) 1.200 1.000 0.800
Observed
Current
NRC, 2001
0.600 0.400 0.200 0.000
Elinor Thomas Milk only
Milk plus starter Diet Type
Calf & Youngstock Specialist Mid & South Wales
m: 07500 979398 e: elinor.thomas@wynnstay.co.uk
Weaned
@thomascalf1
There were 111 treatment meansfrom the literature with values predicted by the current model or the previous model (NRC 2001).
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STRESS AFFECTING DAILY LIVEWEIGHT GAIN
Howoftendowecloselymonitorcalfbehaviour?Isthistellingussomething?Canwelook closertoimprovecalfgrowthandreducemortalityandmorbidityfromastresspointofvi
Stress should be kept to a minimum, especially in the first 90 days of life, this can dictate future performance and profitability. Too much stress will translate negatively so a calm, comfortable, consistent environment is key. Studies show that animals that are generally calmer or less reactive have improved growth rates, milk production or meat quality, improved immune function and decreased physiological responses to stressful events compared to excitable or more reactive animals. During the first weeks of a calf’s life, they must learn where, how and what to eat, these skills can have a profound effect on growth rates. Low vitality at birth, drinking ability and an exploratory active personality are also associated with feed intake, behaviour, and performance. When is Stress in Young Calves? Stress is an environment or situation that is not normal for an animal. Think of a normal daily routine, anything outside of this would influence stress to the calf. Stress can affect the calf physically or psychologically. Some of the physical changes that can occur because of stress are the release of cortisol, adrenaline and other hormones. A psychological indication of stress is a fear of specific objects, environments, or situations. Calves don’t tolerate to change well.
What are the Signs of Stress? • • • • • • • • •
Disease Restlessness Frequent urination Rapid heart rate Trembling Open mouth breathing Sloberring Lack of coordination Huddling
What are the Effects of Stress in Calves? • • • • • • • • •
Reduction in feed intake Lower energy levels Weight loss Reduced fertility Reduction of milk produced Small or premature calves Weakened immune status Disease Reduction of vaccination effectiveness
Every change for a calf is stressful, so limiting these is very important; think of young children learning a new routine and getting used to it, it takes a while and can be chaos. When around calves keep calm and quiet, if you are loud and rough the calves will associate you to this, so when they see you will be fearful. Build a good relationship with them, calves are social animals, get to know them. A small behavioural change in the calf can be a sign of stress or illness, spot it early. When calves suffer stress they may experience a loss of appetite, this will result in lower energy, a lower DLWG and a weakened immune system. When vaccinating stressed calves it will have a less effective response. Calves can face severe consequences when suffering from stress becoming less productive, sick and even die. So, minimise any changes, if any changes need to be done do them very gradually. Stay consistent- calves like routine, get to know the calves and keep them in a comfortable environment, healthy and good nutrition and this will help to improve growth rates, calf health and reduce morbidity and mortality.
Hannah Braithwaite
Calf & Youngstock Specialist Shropshire, Cheshire and N. Wales
m: 07881 093633 e: hannah.braithwaite@wynnstay.co.uk @hannahcalf1
Photograph by Rosie Bennetts
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FOCUS ON CALVES 2022
STRESS AFFECTING DAILY LIVEWEIGHT GAIN
Farmers are looking to produce strong, healthy, profitable animals, we know most of the development happens in the pre weaning stage, this is an important stage that will set them up for the future. Building strong immunity, maintaining good growth rates, high health and decreasing disease exposure are all the factors that go towards improving calf survival and rearing a calf that will be more productive in the herd. Calves thrive on routine! If there are too many changes and not enough consistency are your calves trying to tell you something?
BODYWEIGHT AND AGE OF FIRST CALVING… IT’S A BALANCING ACT Inrecentyearstherehasbeenasignificantpushtocalveheifersyoungertobecomemore ebcient. The benefits of this have been well documented including significantly reducing rearingcosts,whichaccountasoneofthelargestcostsonfarm. With ever increasing costs of rearing, it can be tempting to push heifers to calve down younger than ever. However, to maximise the return on these heifers, it is important to improve the longevity of these animals. Improve herd longevity will reduce the need for as many replacement heifers, allowing for more selective herd breeding, herd growth and increased calf sales, both beef and or heifer sales.
Bodyweight Targets: Younger calving heifers are likely to see lower yields in comparison to heifers calving <24 months. The decreased milk yield is likely to be due to the energy demand for growth over milk yield production. It is important to remember that heifers do not reach their mature bodyweight until around second calving.
To achieve this, it is important to ensure we know how heifers are performing throughout the rearing period. It is far too common to be serving heifers ‘when they look about right’, but maybe we should be looking for a more precise approach. The implications of calving heifers too young or too light can have substantial implications upon heifer performance and longevity, with the risk of:
• Fertility It is important to remember that heifers are still growing. Heifers that are younger and lighter will prioritise energy for growth over fertility. This often leads to heifers requiring more services to conception. To optimise performance and efficiency, cows should calve down every 365 days. Therefore, making sure that animals are getting back in calf as soon as possible will help optimise.
BODYWEIGHT AND AGE OF FIRST CALVING…
• Dystocia Dystocia can have a significant impact upon the health and productivity of heifers. Younger calving heifers are at high risk of dystocia due to being smaller and less developed e.g smaller pelvic area and birth canal. This can lead to caesareans and increased vet and med costs, increasing overall costs and even heifer death. Studies have found cases of dystocia can reduce conception to first service by up to 12%, impacting reproductive performance and efficiencies. Additionally, dystocia leads to higher calf mortality and morbidity. • Milk yield Studies have found a significant correlation between bodyweight and first lactation yield. Heifers which have a higher bodyweight at calving are likely to produce more milk in the first lactation. However, there is a fine line between optimum and excess. Heifers in excess bodyweight are likely to see impacted yields.
Calculate your herd mature weight by weighing a selection of 3rd lactation cows, 100-120 days in milk. This can help you plan and set herd targets for your own farm.
Remember: Heifers that calve down at 22-25 months old take until they are into their second lactation before they begin to payback. How to achieve: Growth Rates To calve down between the optimum 23-25 months old, heifers should grow at an overall average rate of 0.7- 0.8kg/ day throughout the entire growing period. Heifers that achieve growth rates above this or below this are likely have implications. Heifers growing more than this are at increased risk of laying down too much fat, leading to increased body condition scores at calving, which in turn can lead to increased risk of dystocia, metabolic diseases and reduce fertility. Additionally, these heifers can often see lower milk yields. Heifers growing less than this can also face implications such as fertility, lameness and performance reduced. Tip: Achieving higher growth rates (0.8-1kg/day) during the milk feeding stage will allow for maximising growth whilst feed efficiency is highest. Making it the cheapest time to grow calves.
wynnstay.co.uk
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BODYWEIGHT AND AGE OF FIRST CALVING… IT’S A BALANCING ACT
Larger Weight (Based on a Holstein Freisian)
Target Mature Body weight %
Birth
41kg
6%
Post weaning (3 months)
16kg
17%
63%
6Months
185kg
27%
74%
Puberty(9months)
274kg
40%
78%
12months
34kg
50%
82%
Breeding(14months)
37kg
5%
87%
1stcalving(24months)
582
85%
96%
Monitor BCS Ensure that heifers are in a good body condition at calving. Ensure heifers calve down around 3 – 3.25.
Target Mature Height %
Take home message: • Balancing weight, age and size will produce more productive heifers, which will last longer in the herd. • Calculate your herd mature bodyweight to set herd targets accordingly • Monitor heifer growth rates • Consider heifer BCS
Hannah Padfield
Calf & Youngstock Specialist South West, Somerset, Dorset, Hampshire and West Sussex
m: 07968 260110 e: hannah.padfield@wynnstay.co.uk
@padfieldcalf1
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FOCUS ON CALVES 2022
BODYWEIGHT AND AGE OF FIRST CALVING…
Age
COW NUTRITION IS CRITICAL TO CALVING SUCCESS
Whetheradairyorbeefherd,theultimategoalofrearingistogetcalvesoatothebes possiblestarttoensuretheyreachtheirmaximumproductionpotential. Exposure to challenges, for example scours or respiratory disease, can eat into farm profits by negatively impacting calves’ health status and physical performance. Rearers are encouraged to uphold good management practices in order to effectively avoid diseases occurring in the first place.
into the blood. However after approximately 18 hours post birth, the gut starts to close up and absorption of these large proteins and antibodies becomes minimal.
Good calf feeding practice begins with ensuring sufficient cow nutrition in late gestation. Providing cows with sufficient minerals, vitamins and trace elements is key for development of the unborn calf. Of particular importance is selenium, known to support calf vigour at calving and help maintain cow health throughout the transition period. These nutrients are able to pass directly through the placenta from the cow to the calf to enhance health and immune status at birth.
Providing good levels of dietary energy and adequate minerals post-calving is equally important for calving success, specifically to support the cow’s recovery and optimise her fertility as she prepares for the next pregnancy.
COW NUTRITION IS CRITICAL TO CALVING SUCCESS
Conversely, passive protection from disease and environmental pathogens in the form of antibodies are not able to reach the calf via the placenta. Immediately after birth, calves are therefore reliant on the consumption of vital colostrum as their sole source of nutrients of essential antibodies. It is paramount that all calves receive at least 10% of bodyweight of colostrum within the first two hours of life. The timing of this is critical because a new born calf’s digestive tract is designed to allow immunoglobulins from colostrum to pass directly through the gut epithelium and
A cow’s colostrum quality and quantity can vary according to numerous factors, including not only her age, number of lactations and health status, but importantly her diet.
Although in some circumstances additional colostrum or milk supplementation is necessary, allowing calves to suckle as much as possible directly from their dam is the most efficient method of colostrum feeding. With colostrum production beginning approximately 6 weeks pre-calving and reaching a peak in the critical last two weeks of gestation, ensuring correct cow nutrition at this time is key in helping calves get off to a good start. Successful rationing involves achieving the best possible balance of appropriate nutrients, including not only the aforementioned minerals, vitamins and trace elements, but also adequate protein and energy. These nutrients are required to meet the cow’s own body maintenance requirements whilst providing sufficient resources to initiate effective colostrum production. Other nutritional supplements may also be incorporated into the dry cow’s diet to help optimise colostrum production. These include additives such as mannan-oligosaccharides or yeast beta glucans which are documented to support the cow’s immune function, allowing her to maximise nutrient partitioning into colostrum production. Ensuring cow dietary requirements are met both pre and post calving each season is therefore fundamental for producers to optimise calf output and profitability on farm.
Georgina Phillips Technical Adviser Rumenco Ltd wynnstay.co.uk
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OFFSET HOUSING CHALLENGES WITH ATTENTION TO DETAIL
Housingchallengesoftencompromisecalfrearingperformance,butattentiontod inareassuchasnutritionandhygienecanhelpoasettheseweaknesses. Recently, a project team based at AFBI Hillsborough recorded a variety of different housing systems on commercial farms in Northern Ireland. The study was representative of practices on UK dairy units as a whole and certainly highlighted both strengths and weaknesses in terms of replacement heifer calf management practices.
Despite a variety of housing challenges, it was reassuring that the researchers noted that a majority of farms (77.2%) were feeding three litres or more of colostrum to their newborn calves as a first feed. With only 3% of the farms left the calves to suckle the dam after birth, it shows progressive colostrum management from farmers to give calves the best start. Regular measurement of the quality of the colostrum was only carried out by a small number of units (13.65%). This is important to ensure the calf is receiving enough immunoglobulins, as well as giving you an insight into general colostrum quality from your herd. This can be easily done by investing in a simple refractometer. More than 80% of units in the study were feeding calf milk replacer, primarily through teat feeders. Automatic milk feeders were being used on just over 20% of farms; whilst most farms were mixing their milk powder within 90%110% of the targeted concentration (average of 152g per litre), peak volume feeding rates varied significantly. Consequently, it always pays to buy a calf milk replacer from a trusted supplier; a variety of milk replacer products (n =25) were being used on the farms studied, with protein levels varying from 20% to 26% and fat level from 16% to 20%.
Fundamentally though, provided your colostrum management and feeding protocol is sound – and your calves have access to fresh water, roughage, and a palatable starter concentrate – we know that feeding a good heifer calf a minimum of 900g of calf milk replacer daily will allow you to meet optimum rearing targets. Peak milk volume fed ranged from four litres to eight litres per day (median allowance: six litres per day) across the 66 farms and the difference in energy intake may have significantly impacted on the performance of the calves on some of the units. The AFBI project, which I advised on, also highlighted that relatively simple and inexpensive improvements in hygiene could be delivered on many farms. One aspect that was noted was that a large proportion of units did not use or measure disinfectant when cleaning calf pens. Whilst many dairy farms across the UK are hamstrung by antiquated or inadequately designed buildings – where the calf rearing environment is perhaps less than ideal – improving attention to detail in some of these nutrition and hygiene areas will help offset some of these disadvantages. There is a lot you can do to improve the situation and certainly, increased monitoring of calf growth performance and ill health will help identify patterns of issues and pinpoint weaknesses in your system.
Dr Jessica Cooke Research & Development Manager Volac International Ltd
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FOCUS ON CALVES 2022
OFFSET HOUSING CHALLENGES WITH ATTENTION TO DETAIL
The ability of a floor under calves to sufficiently drain urine, spilled milk and water is determined by the slope – from the measurements taken, the slope ranged from 0° to 5.2° across farms. The majority of calf houses (92.4%) were classed as naturally ventilated as they did not have mechanical ventilation present; however, a large proportion had inadequate inlet and outlet areas (53%) to achieve natural ventilation. Additionally, 53% of the main calf houses were adjoined to other livestock buildings meaning that natural ventilation would be further compromised. Space allowance in group pens averaged an ample 3.4m2/calf, but on a small number of farms increasing space allowance would benefit the calves.
Feeding the right amount of a well-mixed, proven calf milk formula is crucial if you are to make the most of a calf’s early life feed conversion efficiency.
A PROACTIVE APPROACH IS KEY TO REDUCE THE INCIDENCE AND CONSEQUENCES OF DEHYDRATION IN CALVES
REDUCE THE INCIDENCE AND CONSEQUENCES OF DEHYDRATION
Diarrhoeaintheyoungcalfisacommonlyoccurringchallengeonmanyfarms.Recent researchbyMSDAnimalHealth,completedaspartoftheirYoungstockSurvey,indicated that90%ofdairyfarmshadexperiencedscourincalvesintheprevious12months,and thatover65%hadexperiencedmortalityduetoscour.Diarrhoeaisreportedasamajor causeofmorbidityandmortalityinearlylife,whichcanresultininsignificanteconom lossesandpotentialwelfarechallenges. A team approach involving calf rearers, vets and nutritionists is central to the successful management of scours. Sharing ideas in order to develop a common approach, with clear protocols, can really support consistent management on farm.
Extreme caution should be taken around home mix electrolytes. The aim is to provide a calf with the optimum and delicate balance of minerals and sugars to support effective rehydration. Get it wrong and you are at risk of making things worse.
Some key focus areas include:
You can’t have enough clean water – make sure all calves have access to good quality, clean water. Regularly test borehole water and ensure head tanks are free from contamination. Clear troughs of bowls out regularly.
Colostrum – successful passive transfer of colostrum is the foundation of a successful calf rearing system. Adequate colostrum intake is crucial for protecting against early life health conditions as well as supporting optimal growth rates and performance. Having a consistent colostrum protocol in place is essential and working alongside your vet to monitor its success is crucial Cleanliness – a well-defined hygiene policy will ensure consistency between everyone involved. Calf units cannot be too clean! Cleanliness starts in the calving pen so stocking rates and clean out protocols should be regularly assessed, calf pens should be cleaned and disinfected after every occupancy. Make sure a disinfectant active against the common scour bugs is used and applied at the correct concentration for the correct amount of time. Focus on keeping all feeding equipment clean, ensure teats are regularly changed. Rehydrate for recovery – proactively offer OsmoFit as soon as calves fail to drink their milk allocation – one of the first sign that something is not right. Never mix OsmoFit in milk replacer or milk, but feed separately between milk feeds.
Energy is key for supporting calves to recover during an outbreak - milk feeding should always be fed as close to appetite as possible; LifeStart Science highlights the benefits of a minimum of eight litres per day. During a scour outbreak consider reducing meal size and increasing meal frequency if required to support intakes. It is essential to continue to feed a high quality, highly digestible milk replacer with a high energy density and low osmolality – adequate nutrition in early life can provide great support during a disease outbreak. What is causing the problem? Quick pen side scour diagnostic kits can be useful but the results need careful interpretation that can be supported by your vet. Additional testing can help highlight root causes, allowing a tailored treatment plan to be developed. Are you set up to prevent calf scours eroding your profitability and affecting the genetic potential of the next generation of high-quality cows?
Jess Yeomans
Senior and Technical Calf & Youngstock Specialist Shropshire, Cheshire, Herefordshire, Worcestershire and N. Wales
m: 07990 584740 e: jess.yeomans@wynnstay.co.uk
@charltoncalf1
Photograph by Sarah Griffiths wynnstay.co.uk
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OsmoFit The next generation oral rehydration solution for calves. Based on a patent pending formula which provides precisely balanced nutrient supply.
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FOCUS ON CALVES 2022
SALMONELLA - SPOT IT, STOP IT!
Salmonellainfectioncanhaveseriouseconomicconsequencesonfarm,presentingit amultitudeofdiaerentwaysandalsoposingazoonoticrisktohumans. There are several different groups of Salmonella, only two of which we can vaccinate for (S.Dublin and S.Typhimurium). We often see issues with Salmonella infections in youngstock and taking the time to assess the risks on your own farm can help identify if improvements can be made to reduce the spread of disease. So how might it present in youngstock? Salmonella bacteria infects calves via the faecal oral (muck to mouth) route. Once ingested the bacteria invades the lining of the gut and the enterotoxin causes extreme damage reducing absorption capacity. This can result in scours, septicaemia, dehydration and potentially death. Other, more unusual, signs can include damage to the tips of the ears, when septicaemia causes blood flow to the extremities to be reduced. Any calf suffering from stress or poor immunity is going to be more susceptible to infection.
2. Optimise immunity: • Ensure all calves receive a volume equalling 10% of bodyweight of good quality colostrum as soon as possible after birth. Ideally this should be in the first couple of hours, as the gut’s capacity for absorbing antibodies reduces quickly after birth. • If S.Dublin or S.Typhimurium is identified on farm vaccination can provide whole herd immunity. Timing of this may depend on the outbreak and clinical signs seen so is best decided upon with your vet. Ensuring revaccination 3-4 weeks prior to calving will ensure colostrum contains antibodies for Salmonella, which will help improve calf immunity and health.
Any calf suffering from stress or poor immunity is going to be more susceptible to infection
So how do I know if Salmonella is on my farm? There are a number of different samples that can be taken to work out if Salmonella is a potential risk on your farm. Firstly, any scouring calves should be sampled and faecal culture can reveal if Salmonella is the causative agent.
SALMONELLA - SPOT IT, STOP IT!
Blood sampling a group of youngstock approximately 3- 6 months of age and testing for antibody can show if they have been exposed to Salmonella. Finally, bulk milk antibody is a really useful tool to show if Salmonella is being shed by adults on the farm. Salmonella can be shed in the faeces of asymptomatic cows and so does pose a real risk to calves when these animals pass through the calving yard. So how can you control the risk on your own farm if Salmonella is present? 1. Calving yard management: • Ensuring that the calving yard is cleaned out regularly (at least every three weeks and more frequently if stocked high or a large number of calvings) will reduce the infection pressure. • Don’t allow sick cows in the calving pen. These cows are potentially at risk of spreading large numbers of bacteria if they are infected. • Separate calves and dams as quickly as possible, to reduce the chance of suckling and ingestion of infected faeces.
3. Cleanliness is key - the solution to pollution is dilution: • Ensure all calf feeding equipment is cleaned thoroughly. You can measure how effective your cleaning protocol is using a luminometer. This machine measures bacterial ATB (bacterial energy), which gives a direct indicator as to how much bacteria is on the equipment and how effective your cleaning protocol is. It can be a good starting point to see if any modifications to the cleaning protocol are required. • Ensure water, feed and any equipment used in the calf housing is kept clean and free from faecal contamination. • Ensure plenty of fresh clean straw is regularly applied and calf housing is cleaned out with an appropriate disinfectant. If you are having any challenges with youngstock disease, it is always worth discussing with your vet any diagnostics and potential action you can take. Salmonella can present in many different ways and so knowing what samples to take and how best to manage the risks on your own farm should reduce the impact of the disease.
Hannah Batty
Veterinary Surgeon & Director LLM Farm Vets
wynnstay.co.uk
20
ROUTE OF TRANSMISSION OF BOVINE TUBERCULOSIS
‘Bovine Tuberculosis (TB) is an infectious disease of cattle. It is caused by the bacterium Mycobacterium bovis (M. bovis) which can also infect and cause disease in many other mammals including humans, deer, goats, pigs, cats, dogs and badgers.’ In England overall, the herd incidence rate for the 12 months to end December 2021 was 8.8, a decrease of 0.6 from the previous 12 months. Scotland, which has had officially TB-free (OTF) status since 2009, herd incidence and herd prevalence remain very low and stable. In Wales herd incidence increased by 0.5 compared to the previous 12 months, and herd prevalence increased slightly between December 2020 and December 2021. A 2018 paper from a Michigan dairy herd investigated the route of infection and how it correlates with anatomic distribution of lesions in cattle and cats. All adult cattle and calves down to 1 day of age were tested using the caudal fold test, 451 in total. There were 80 suspects, (18% reactor prevalence); 56 adult cattle and 24 suspect calves.
The differences in anatomic distribution between the adult cattle versus the calves and cats from this facility were striking. In the adult cattle, gross anatomic, histologic, and culture-positive results were predominantly within their thoracic lymph nodes, whereas both calves and cats had statistically significant higher prevalence of culture positives in their abdominal lymph nodes. This difference in anatomic distribution appears to correlate well with the likely routes of transmission of TB in this case. It would be suggested the adult cows would have contracted the disease through airborne transmission, as they would have been housed in the same shed, whereas the calves and cats that were fed waste milk (colostrum and antibiotic – contaminated milk) most likely caught the disease by oral ingestion. In addition, the 46% prevalence of thoracic culture positives in calves is most likely related to the lateral transmission of the tuberculosis by aerosol route. These calves started out in individual hutches, but after 3-6 weeks are raised in group pens. The aerosol route of infection is believed to be responsible for 80–90% of all tuberculosis infections in cattle.
Confirmatory gamma interferon testing was performed on all 80 suspect cattle. An initial submission of nine adult cattle that were strong caudal fold test reactors (caudal fold swellings of several cm in diameter) was made to the Diagnostic Centre for Population and Animal Health (DCPAH; Lansing, Michigan), where they were euthanized and subjected to full autopsies.
It is important to note that when considering oral transmission of tuberculosis, it requires 16–18 million times the infective dose compared to respiratory inoculation, so would be more of a risk if the milk is fed for a prolonged length of time. In this herd, at least two adult milking cows were shedding M. bovis into their milk, and because only 19 of >300 adult milking cattle had their milk tested, there were likely additional cows shedding M. bovis. In this research waste milk was routinely fed to calves for up to six months and to cats continuously, this provided ample opportunity to expose these animals by ingestion.
The remaining 47 adult cattle that were classified as reactors were shipped directly to slaughter facilities, where they were examined by U.S. Department of Agriculture veterinarians similar to the autopsy protocol performed on the initial nine cattle.
I fear TB is often a taboo topic and something I appreciate we are all trying to eradicate, let’s not forget the routes of transmission and ensure we are minimising risk where possible:
24 strong caudal fold test reactor calves were subsequently submitted to and autopsied at DCPAH following protocols identical to those described for the adult cattle.
• • • •
21 domestic cats were collected on the farm, euthanized, and submitted to DCPAH for autopsy. In a similar fashion to the cattle, head, thoracic, and abdominal lymph nodes were collected from the cats and submitted for histologic examination, mycobacterial culture, and PCR testing at DCPAH.
Via respiratory route Via infected milk Before birth through placenta Indirectly through environmental contamination.
Millie Hendy
Senior Calf & Youngstock Specialist South West and Midlands
m: 07717 495746 e: millie.hendy@wynnstay.co.uk @hendycalf1
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FOCUS ON CALVES 2022
ROUTE OF TRANSMISSION OF TUBERCULOSIS
Life without TB no doubt would make farming a happier, more profitable experience for many of us. Saying this some have adapted within their areas and founded their businesses due to the disease, but we still need to aim to reduce the total number herds under restriction.
POSTBIOTICS - A GAME-CHANGER IN CALF HEALTH Two thousand years ago Hippocrates stated that “All disease begins in the gut”. Science researchhasnowrecognizedthatguthealthisparamounttocalfhealth. Calf diarrhea is still a big challenge on so many UK dairy farms; unfortunately, it is often also a gateway disease to other issues, increasing the risk of pneumonia by eight times. Precision Microbes believes “all health begins in the gut” so, we are revolutionizing the gut health market with a unique probiotic and postbiotic liquid.
What Have We Done Differently? We have a liquid containing good bacteria/probiotics and all their metabolites postbiotics in the one liquid; live bacteria is present in a dormant state, with all their metabolites (postbiotics). The metabolites being produced in the liquid means speed of action, and this is something we know from trials conducted that farmers can see in their calves themselves.
POSTBIOTICS - A GAME-CHANGER IN CALF HEALTH
The Gut Microbiome The importance of gut health and the role of these beneficial microbes (good bacteria) in digestive health, immunity, and protecting young calves against pathogens is widely accepted. A healthy calf is the lifeblood of future farm performance. Likewise, a healthy digestive system becomes the foundation of future farm performance from beginning to early life. Understanding this, Precision Microbes has developed game-changing science around the supplementation and support of better gut health.
Unique culturing techniques are also used; having acidadapted bacteria also means the microbes and their metabolites get to where they need to be. During the trials carried out, we consistently saw better digestive health and improved FCE where our products are used from birth to weaning. With seventy percent of a calf’s immune system in its digestive tract, we are also notably supporting better immune health in young calves. Our unique liquid combination of probiotic and postbiotic can be given orally or fed in milk daily.
Gut Health To improve gut health, we need to look at getting the right microbes in the correct numbers to where they need to be. We must understand that these beneficial bacteria (probiotics) are like factories and it is the metabolites they produce that are important. These metabolites are postbiotics, ‘where the rubber meets the road’ in good gut health. Postbiotics are the key metabolites that regulate digestion, immunity, and protect against pathogens.
Rapid Stabilization A bottle on every farm. Most farmers’ experience with Precision Microbes starts with our 1L bottle when given early to a calf recovering from diarrhea or not performing. They see improved appetite, the speed of action, gut health recovery, and improved calf health. So they quickly move to the 10L product and start giving it from birth to all calves. We have been told by many farmers that they wonder how they ever reared calves without Precision Microbes.
Photograph by Jo Smith wynnstay.co.uk
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POSTBIOTICS - A GAME-CHANGER IN CALF HEALTH
Good bacteria are like factories in the digestive tract producing metabolites (postbiotics) that act to improve digestion, support immunity and protect against harmful pathogens in young calves. Photograph by Alice Staggs
In the most recent trials, the focus has been on how we can improve calf performance. The dairy to beef calves trial were given 30ml daily in milk, from arrival to weaning.
“Over a twenty-year veterinary career working and traveling across global agriculture. I haven’t seen anything like the Precision Microbes’ range to be indeed game-changing in their application on the farm. With a fast-acting recovery from diarrhea and where they are used long-term, seeing the difference in calf health has been extraordinary. These are the most exciting gut health products on the market. My experience with Precision Microbes products is to say with confidence all health does begin in the gut.”
We have seen an ADG difference of 115g/day in the precision treated calves versus the control group.
For more information and testimonials on results from onfarm success, visit www.precisionmicrobes.com We look forward to working with farms and their calves to transform gut health with our cutting-edge science.
Tommy Heffernan Veterinary Consultant
Contact your local Wynnstay Youngstock specialist about using Precision Microbes on your farm. 23
FOCUS ON CALVES 2022
POSTBIOTICS - A GAME-CHANGER IN CALF HEALTH
The Science of Probiotics and Postbiotics It is well established that probiotics have a role in improving gut health. How we use them is so important. Precision Microbes are a game-changer in calf health because the liquid contains beneficial bacteria in a live but dormant phase with their postbiotics.
BEATING COCCIDIOSIS – WHAT’S THE BEST WAY?
Askafarmerwhatcoccidiosisis,andheorshewillinherentlymention‘bloodscour’ Aretheyright? Yes and no.
In some cases, the stressor is obvious. In cases where the environmental burden of coccidia is extremely high, stressors are less obvious, and this 4% figure can climb higher. This 4% figure will also climb after extremes in weather or handling events such as a long period of transport.
Coccidia are species-specific, single-celled organisms of the protozoan family. An infected host (e.g. lamb/calf) will shed billions of coccida oocysts in their environment. These oocysts are extremely resilient and can persist across seasons. As a result, it is almost inevitable that commercially farmed animals will be exposed to coccidia.
Generally, after a period of consistent exposure, an animal will be fully immune to both sub-clinical and clinical coccidiosis. This is what we aim for as farmers – natural immunity against the parasite, because it is inevitable that they will continue to be exposed to burdens throughout their lives. In fact, older immune animals often carry the parasite in their intestines and act as a source of pathogenic coccidia oocysts for young animals. These older animals will be perfectly healthy, as their immune system is supressing the parasite, but still shedding small amounts of coccidia oocysts into the environment that can affect our young animals. This is why eradication of the parasite from a farm is unrealistic.
As farmers, we want our animals to be exposed to coccidia. Coccidia and coccidiosis are not the same thing. Coccidiosis is what occurs when immuno-naive animals (young or stressed) are exposed to a significant burden of pathogenic coccidia. The term ‘pathogenic’ is important here; in calves and lambs, there are two dangerous species of the parasite and 8-10 other harmless species. A basic faecal sample will not differentiate and so shouldn’t be the sole determinant of a coccidiosis diagnosis.
BEATING COCCIDIOSIS – WHAT’S THE BEST WAY?
Coccidiosis can be either clinical (usually 4% prevalence in an infected group), where the animal exhibits scouring, straining and in cases death, or subclinical. The subclinical form of coccidiosis, on average, causes a reduction in thrive of ~19% across full groups of infected animals.
The problem is that the best way to achieve immunity is via a sustained exposure to small burdens of the parasite, but on a commercial farm a naïve animal can very quickly be exposed to huge burdens which overwhelm their immune systems. Add in the typical stressor events found on a UK farm in the springtime (weighing, vaccinating, transport, tagging, weaning, turnout etc.) it’s easy to see why coccidiosis is becoming more and more common.
The number one weapon a farmer has against coccidiosis is not a drench, a medicated bucket or a medicated ration. It is in fact the animal’s own immunity. When an animal is challenged with pathogenic coccidia, their immune system springs into action. A naïve animal‘s (one that hasn’t had previous exposure) immune response to the parasite will require the diversion of significant ingested energy to ‘fuel’ the immune system, reducing available energy for growth. This leads to the group-wide 19% reduction in thrive. The 4% of animals who display clinical symptoms are generally the ‘most stressed’ in a group – stressors for example being a lack of colostrum at birth, a dam with poor milk ability, them being twin, being over-handled etc.
To help the animals’ immune system we first optimise the environment. Keeping it a clean as possible, this means using lots of clean dry bedding, using the approved disinfectants, keeping feed and water troughs clean and keeping yourself clean (boots dipped etc.) In general, the above steps will act to postpone coccidiosis outbreaks on a farm. When it then occurs, we have a number 3 licenced medications we can use as a helping hand to the animals’ immune system. A combination approach of enhancing the animal’s immunity, gold standard hygiene and an optimally-timed diclazuril drench represent a best practice strategy.
Millie Hendy
Senior Calf & Youngstock Specialist South West and Midlands
m: 07717 495746 e: millie.hendy@wynnstay.co.uk wynnstay.co.uk
@hendycalf1
Photograph by Alice Staggs
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CLOSTRIDIAL DISEASES IN DAIRY CALVES
Clostridialdiseasemanagementisacommontopicinsheepfarmingwithmostofthe flockvaccinatedbeforelambingforpreventionthroughpassivetransfer,butitisnot muchthoughtbycalfrearers. There are multiple clostridial diseases that can affect cattle, however the most common type of toxic intestine infections in young calves are caused by Clostridium perfringens. These differ from other scour causing pathogens (E. coli, crypto, cocci) in that calves rarely show any signs of ill thrift and may not even scour before the toxins enter the blood steam followed by inflammation, shock and cardiac arrest. What are C. perfringens? They are gram-positive anaerobic bacteria commonly found in soil and water but they can also occur in improperly thawed colostrum, calf housing and they naturally occur in the intestinal tract of adult cows where they can be passed out in the faeces. There are five different subtypes of C. perfringens that we should be aware of. Why do they affect calves and not adult cattle? C. perfringens live and multiply off sugars and starches in the small intestine. These sugars and starches are digested in the rumen in older animals whereas milk feeds in calves by-pass the rumen, entering the abomasum then the small intestine.
What causes an outbreak? C. perfringens are naturally occurring in the calf’s gut but harmful rapid multiplication can be prompted by abrupt dietary changes, inconsistent feeding or any stressful events that disrupt feed intake. Diagnosing C. perfringen outbreaks: diagnosis by postmortem is difficult as the clostridial organisms that normally live in the gut multiply rapidly after death. Infections also display the same signs as salmonella, cocci and E. coli, therefore, post-mortem for diagnosis must occur quickly after death. Therefore post mortem for diagnosis must occur quickly after death. Preventing C. perfringen outbreaks: there are two prevention methods we can combine to minimalize the risk of an outbreak: 1. Reducing exposure: Despite the fact clostridial organisms occur naturally in the calves gut and environment the fewer organisms they are exposed to the smaller the risk of infection therefore sanitation of the calving area can reduce exposure. 2. Enhancing immunity: Vaccination of cows before calving can offer the calf passive immunity via their colostrum giving them at least 12 weeks protection against types A, B, C and D. Covexin 10 covers these four strains as well as six other clostridial pathogens.
The 5 subtypes: Major Toxin
Symptoms
A
AlphaToxin
Abomasalbloatandinflammationwithorwithoutulcers,necrosis (tissue death) of the abomasum and small intestine surfaces may also bepresent.
B
BetaToxin,AlphaToxin, EpsilonExotoxin
Causeshemorrhagicenteritis(bloodyscour).Betatoxinsaredestroyed bytheenzymeTrypsin.Trypsininhibitorsarepresentathighlevelsin colostrumandtransitionmilksooccursinearlylife.
C
BetaToxin,AlphaToxin
Asabove.
D
EpsilonExotoxin,Alpha Toxin
Causesseveredamagetothegutliningallowingtoxintoenterthe bloodstreamandaaectorganssuchastheheart,lungsandbrain. OppositetoBeta,Epsilonrequiresenzymestobecomeactiveso occursinslightlyoldercalves.
E
IotaToxin,AlphaToxin
IotatoxinactsinthesamewayasEpsilonsosymptomsareasabove.
Laura Monk
Calf & Youngstock Specialist Cornwall, Devon, Somerset, Dorset, Hampshire and West Sussex
m: 07767 275662 e: laura.monk@wynnstay.co.uk @monkcalf1
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FOCUS ON CALVES 2022
CLOSTRIDIAL DISEASES IN DAIRY CALVES
Type
LIFETIME IMPACT OF PREWEANING NUTRIENT SUPPLY IN DAIRY CALVES
The survival of replacement calves and heifers, the subsequent survival of lactating d cows in each lactation and the ebcient conversion of feed into milk, all contribute to th environmentalimpactofdairyproduction. In recent years, early life nutrition of the calf has been recognized as having long lasting effects on health and productivity throughout the lifetime of the animal.
Elevating the level of nutrition supplied to young calves, by increasing nutrient supply via the milk feed, is associated with beneficial effects on growth and future lactation performance.
LifeStart by Trouw Nutrition was introduced in 2014. The science-based programme has focused on the critical first months of a dairy calf’s life. The programme has aimed to increase, improve and communicate knowledge on all areas of early life nutrition including milk quantity, milk quality as well as practical feeding considerations. Over the last few years the LifeStart research group, alongside collaborators including Cornell University, has investigated growth, metabolism and lactation performance of calves fed two different levels of milk preweaning – elevated and restricted levels. After weaning all animals were reared together and later entered the dairy herd. As anticipated calves fed an elevated level of milk replacer preweaning had a higher average daily gain, resulting in a weight difference at weaning. This body weight advantage remained until insemination, resulting in lower age at first service and a higher conception rate. The number of services required was also reduced. This trend continued into the first and second lactation, where improvements in first service conception rate were found.
During the first and second lactation, cows that were fed the elevated level of nutrition preweaning, yielded more fat and protein corrected milk, consumed more forage and maintained a lower body condition score. In addition to this the survival rate until fourth calving was significantly improved. At specific time points throughout the trial blood samples were analysed in order to investigate any potential differences in metabolism between the two groups. Samples were taken at day 2, 49, 330 days of age and at 60 days in milk during the first lactation, blood samples were taken and analysed for over 900 blood metabolites. Analysis shows that multiple pathways which were affected by elevating preweaning nutrition, and that these differences were still expressed differently in the first lactation. These differences in long lasting metabolic configuration, can potentially explain the differences observed in performance and survival which were described in the study. LifeStart Science by Trouw Nutrition continues to push the boundaries of calf nutrition research in order to support farmers with products and practical solutions to optimise calf and heifer performance. On farm examples demonstrate clear long-term benefits on fertility, survivability and lactation performance providing a clear return on investment. Investing in calf nutrition is an investment for the future herd.
Dr Leonel Leal
Team Lead - Calf and Heifer Research Trouw Nutrition Research & Development
Unlock the full potential of your calves Achieve higher performance through a unique focus on early life nutrition. ruminants.lifestartscience.com
wynnstay.co.uk
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The original Energized Calf Milk just got even better… Elixir+ They’re queueing up for
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FOCUS ON CALVES 2022
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