Lecture 4: Calf management
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This document provides guidelines for calf rearing, including colostrum feeding, milk feeding amounts and schedules, housing, and general health management. The key recommendations are to feed colostrum within the first 8 hours, provide 8-10% of birth weight in milk daily for 8 weeks, house calves individually until 1 month old, and clean and disinfect housing and equipment regularly. Basic principles like cleanliness, adequate colostrum and nutrition, and preventing stress are essential to successful calf rearing.
Lecture 4: Calf management
- 1. Dr. Rabie Hassan Fayed Prof. of Animal & Poultry Management Faculty of Veterinary Medicine Cairo University, Egypt
- 2. it is obvious that the first essential of good calf husbandry is to keep the dairy calf alive and fit enough to perform well later on. Many systems have been developed to rear calves. There is no "best way". Many combinations of feeding, housing and management can be successful. For any rearing programme to be successful, certain basic principles, which are outlined in this lecture, must be applied
- 3. Dairy cows should calve in small sheltered paddocks separate from other livestock. Use of these paddocks should be rotated to avoid an excessive bacterial build-up. Alternatively, where there is a disease problem, or when there is adverse weather, dairy cows should calve in maternity boxes (3,6 x 3,6m) which must be disinfected after each calving. Ensure there are no sharp objects, on which the calf or the cow, can injure itself, in the maternity box. Supply fresh bedding, which must be burned after use, for each calving.
- 4. The cow's first act after calving is to lick the calf dry. This not only establishes a bond between mother and her offspring, but also reduces the risk of the calf becoming severely chilled through excessive heat loss from the evaporation of the foetal fluids. The stockman should be prepared to give the calf a good rub down, especially in cold weather, if the cow is unable to lick the calf dry. The stockman should clean the foetal membrane from the calf's nose and mouth, rub the calf dry, And then disinfect the navel with a 20% iodine solution.
- 5. Colostrum intake has been shown to be the single most important factor in calf rearing, because calves that receive inadequate colostrum are liable to excessive disease Its high nutritive value ensures that the calf has the best possible start to life. Colostrum is also the calf's sole source of protection against the bacterial diseases which it is likely to encounter in early life. The rate of absorption of the protein antibodies, is greatest during the first six hours after birth. The calf should suckle its dam for at least the first 24 hours of its life. The suckling of colostrum from, or in the presence of, the dam has been found to be most effective for the absorbtion of antibodies. The stockman should ensure that the calf has a good feed of colostrum within the first eight hours.
- 6. It is rich in energy, having a high oil content, and energy is more important to the calf than is protein at this stage of life. It is rich in vitamins, particularly vitamin A, which is essential for the efficient development of the lymphatic system and epithelium tissue, which are vital for the animal to resist disease. It has a laxative effect, which is essential to clear out the
- 7. Colostrum is not only a source of antibodies, but is also food for the young calf. I f no colostrum is available from the dam or another cow, the following mixture may be substituted: One whipped egg 0,3 litre water 0,6 litre whole milk 0,25 ml castor oil Feed this mixture 3 times daily for the first 4 days of the calf's life, and in addition, administer an injection of vitamin A. In addition, a daily injection of a tetracycline antibiotic has been found to be successful in reducing calf losses when no colostrum is available. Ideally, a quantity of frozen colostrum should be available on the farm. Freeze in plastic packets, each sufficient for a single feed.
- 8. The amount of milk to be fed depends on the size of the calf, and is usually 8 to 10% of its birth mass. Do not overfeed because this may result in digestive upsets and scours. When restricted levels of milk are fed, or "high dry matter" milk replacers are used, the calf will get insufficient liquid in its feed for its daily requirements, and water must be freely available. Remove the concentrates and water for half an hour during and after feeding milk (or milk substitute), otherwise calves may engorge themselves on these, resulting in bloat.
- 9. The number of feeds per day will depend upon the volume fed, the maximum permissible volume per feed being 2 litres for Holstein- Friesland calves and proportionately less for other breeds. The total volume of milk fed per day will depend upon the growth rate desired for the calves. Ideally milk should be fed at body temperature, 37° C, or, if this is not possible, at a consistent temperature, and at the same time every day. teat feeding should be better, but this has not always been shown in practice. Buckets have the advantage of being far easier to clean and to disinfect, reducing the incidence of scours. It must be remembered that calves have to be taught how to drink from buckets. This is done by gently guiding the head of the calf into the milk by allowing it to suck one's fingers, previously dipped into the milk.
- 10. To ensure early weaning it is necessary for the calves to start eating concentrates at an early age. The calf can be encouraged to eat by rubbing a little of the concentrate mixture on to its muzzle, or by putting a small amount into the bucket just before the calf has finished drinking its milk.
- 11. Feed the calf whole milk at 8 to 10% of its birth mass per day for 8 weeks. The quantity of milk fed can be reduced gradually from the fourth week of age, depending upon the desired growth rate. Calf starter meal (19% CP; 12,6 MJ/kg DM), good quality hay and water must be available after the first week.
- 12. Breed Quantity (L/day) Holstein-Friesland Ayrshire or Guernsey Jersey 4,0 to 4,5 3,0 to 3,5 2,0 to 2,5
- 13. Milk feeding is restricted to 6 to 7% of birth mass or to that amount required for maintenance . The lower milk intakes encourage the consumption of dry feed. Calf starter meal (highly palatable), fed fresh daily to ensure a good consumption, hay and water must be on offer by the time the calf is one week of age. Owing to the low volumes of milk fed, a once a day feeding system can be adopted. In cold weather the chill should be taken off the water, otherwise the consumption of concentrates will be reduced, owing to poor water intake. The milk should be completely replaced by concentrates between the third and fifth week, but only after the calf is consuming 0,5 kg calf starter meal per day. The majority of calves can be weaned at 5 weeks of age, the main exceptions being those which have suffered a severe setback from diarrhoea. This system is not recommended for calves of the smaller breeds, e.g. Jerseys.
- 14. When feeding milk-replacers, follow the manufacturers' directions. Replacers low in fiber are preferable because these contain the least amount of vegetable protein. The most suitable milk replacers consist almost entirely of milk by- products. In colder areas, or during winter, use a milk substitute with a high fat content (15 to 18%), otherwise all of the energy available to the calf will be used by the calf to keep warm by shivering, rather than for growth. Some milk replacers have a high DM content, necessitating that a supply of clean water always be available to calves on these feeds.
- 15. This is an excellent feed for calves. It can be substituted for whole milk when calves are two weeks old. T he change can be made abruptly, or gradually over 3 days. When calves are about 4 weeks old, gradually increase the quantities to double those for whole milk . Continue to feed skim milk until the calves are 4 to 5 months old. Make the transition to dry feeding gradually, regardless of age. Skim milk is low in vitamins A & D, so supplements must be given (7000 i.u. vitamin A and 1750 i.u. vitamin D), either in the calf starter, or by injection. Supplementary calf starter (12% CP; 12,6 MJ/kg DM), hay and water must be available to the calf from 4 weeks of age.
- 16. Sufficient surplus colostrum is produced in most dairy herds to feed all heifer calves from birth to weaning at 5 weeks of age. Diluted or fermented colostrum should not be fed to calves less than 3 days of age because it lacks viable antibodies. Surplus colostrum can be preserved by freezing, fermentation or by chemical means. Freezing is the best method of preservation, resulting in negligible nutrient losses, and in retained palatability. Colostrum can be preserved, by freezing, in the amounts required for use. Bloody colostrum freezes well, but cannot be fermented. Colostrum can be preserved by natural fermentation at ambient temperatures below 25° C. At temperatures above 25° C putrefactive fermentation occurs, necessitating the addition of a chemical preservative.
- 17. Mastitic milk, and milk from antibiotic-treated cows, can be successfully fed to calves, replacing whole milk or extending surplus colostrum supplies. Heifers fed mastitic milk must be fed and housed individually in pens, to prevent contact between these calves. Bacteria can survive in the mouth for more than 24 hours. If calves fed this milk suckle each other, it can cause infection of mammary tissue, causing heifers to calve down with mastitis. Mastitic milk should not be fed to calves younger than 4 days of age. The milk from antibiotic-treated cows should not be incorporated with the colostrum for fermentation because the antibiotic residues will inhibit the fermentation process.
- 18. Scours can be the symptom of a disease, or the result of poor nutrition. Nutritional scours usually results from an excessive level of carbohydrate in the diet, or from overfeeding. Scours can be prevented in the following ways: Calves must get adequate amounts of colostrum as soon as possible Do not overfeed calves. Use good quality milk replacers. Feed milk at body (37° C) temperature if possible, otherwise feed at a constant temperature. Feeding should be done at regular times. The utensils should be scrubbed and sterilized after each feed.
- 19. Should scours occur, it should be treated as follows: ◦ Do not feed for 24 hours, but allow free access to water. ◦ Re-introduce the milk ration at maintenance level (Table 2) after 24 hours, and, as soon as the dung is normal, feed as usual. ◦ Scours caused by disease organisms will require a prescribed antibiotic treatment. ◦ An electrolyte solution should be administered to combat dehydration. If a commercial product is not available, the following solution, fed three times daily, can be used: 1 teaspoon salt 1 teaspoon bicarbonate of soda 1 teaspoon potassium chloride 2 tablespoons glucose 1 litre water. Isolate sick calves.
- 20. Bloat occurs as a result of excessive gas production in the reticulo-rumen of calves. Excessive consumption of highly-fermentable feeds is likely to cause bloat. The consumption of large volumes of fluid also can cause bloat. Therefore it is recommended that water and calf starters be removed prior to feeding milk and only returned half an hour after feeding milk. The inclusion of 10% hay in the diet is very effective in reducing the incidence of bloat.
- 21. Milk feeding can be stopped abruptly, or gradually by decreasing the milk supply daily over a week. Weaning should not occur before the calf has consumed 0,5 kg calf starter meal per day for three consecutive days. Abrupt weaning is not advocated for calves receiving large volumes of milk daily. Do not place undue stress on the calves at weaning, for example by moving pens, castrating and dehorning. Move calves to new pens 7 to 10 days after weaning. Dehorning and the removal of extra teats should have been done by one month of age.
- 22. The ability to identify animals is essential for good record keeping and for efficient management. At birth, some form of permanent identification such as ear notches or tattoos, is essential. Later, for convenience and to facilitate identification, ear tags (which however, may fall out) are useful. For dairy cows, freeze brands on the rump are useful for identification in the parlour. Freeze branding can be done successfully when heifers are first mated, or after they have been confirmed as being pregnant
- 23. When calves are artificially reared from soon after birth, some form of housing is required. Research data indicate that it is best to keep calves individually penned until they are at least one month old or, if maximum weight gains are required, until three months of age. The main advantage of individual housing is that the incidence of cross-infection is reduced.
- 24. An important factor to consider when rearing calves on an early weaning system, where milk feeding is restricted, is that the young calf cannot adequately control its body temperature. It must therefore resort either to eating more to increase heat production gained through the digestive process, or to shivering in order to gain heat from muscular activity. Either of these will lead to a decreased food conversion efficiency. Calves on restricted milk diets (maintenance levels) will require more milk to maintain body heat production in cold weather than in hot weather
- 25. Ventilation in calf houses is important, but at the same time, draughts must be avoided. Without good ventilation, the air becomes warmer and more humid, causing an increased concentration of ammonia, other gases and harmful bacteria, resulting in respiratory problems in the calves. The calf house, in addition to being well-ventilated, should allow plenty of sunlight to enter.
- 26. Specialized isolation pens, with infra-red lamps to provide localized heat in cold weather, are desirable for sick calves, or for weak calves that were removed from their dams at birth. These pens should be easy to disinfect. Calves should be housed in well-ventilated but draught- free housing. Individual housing in crates Group housing of approximately 5 calves of the same age and size is another possibility. Allocate 1,4 to 1,8 m2 per calf, with 350 mm trough space per calf younger than 3 months. To avoid calves suckling each other, tie them up for 20 to 30 minutes after feeding milk. For detailed plans on calf housing see KwaZulu-Natal Dairy Leaflet 7.1.
- 27. Milk-feeding utensils should be cleaned thoroughly after use by rinsing in cold, or luke warm water and then by washing them in warm water containing both a detergent and a disinfectant. After washing, they should be rinsed in cold water and set out to dry (do not use a drying cloth which may be "dirty", rather drain and allow to air dry). Cleanliness is essential in calf houses. Calf pens must be cleaned and then disinfected between the removal of older calves and the entry of younger calves. The process consists of two distinct operations: the removal of all dirt such as dust, dung, cobwebs (cleansing). the application of a disinfectant to the cleaned surface to kill micro-organisms. Cleaning should be done on a daily basis. Beware of leaving the calf house damp and humid. This may result in respiratory disease in the calves. Cleaning can be done using power hoses (not when calves are present) or scrubbing brushes. A washing soda solution (4%) can be used. When disinfecting while calves are in the house, care must be taken with the kind of disinfectant used. The spreading of lime (to change the pH) or chlorinated lime (bleaching powder) on the floor will be beneficial
- 28. Commercial disinfectants containing sodium hypochlorite or iodophors can be used for disinfecting. Care must be taken to ensure that the surface to be disinfected is thoroughly cleaned because these substances do not work well when organic material is present. Alternatively, a solution of 4 to 5% formalin can be used as a disinfectant. Formalin is efficient in killing bacterial spores and viruses even in the presence of organic matter. It should be noted that disinfectants do not act instantaneously. In general they require at least half an hour to act effectively, then they should be rinsed off after use, especially on metal surfaces.
- 29. FURTHER READING WEBSTER, J., 1984. Calf husbandry, health and welfare. London: Granada. WILSON, P.N. & BRIGSTOCKE, T.D.A., 1981. Improved feeding of cattle and sheep. London: Granada. ROY, J.H.B., 1980. The calf. 4th ed. London: Butterworth.