Nutrition and Feed Management: Unweaned Calves

Source: National Farm Animal Care Council Code of Practice for the care and handling of farm animals – Dairy Cattle, Section 2.2.1

The early nutritional status of calves has a marked influence on their later productivity. Colostrum feeding management has an important influence on the health and welfare of calves. The timing of first colostrum is particularly important since calves’ ability to absorb colostrum is substantially reduced six to eight hours after birth. The ability of the calf to defend itself against infectious diseases is directly related to the amount (liters), quality (immunoglobulin level and hygiene), and timing of colostrum intake. The result of inadequate colostrum intake is a low concentration of circulating immunoglobulin (Ig) in the blood of the calf, a condition known as ‘failure of passive transfer’ (FPT) (23).

Calves are motivated to consume large volumes of milk (in excess of eight liters per day for Holsteins). Calves especially benefit from higher milk intakes during the first four weeks of life when their ability to digest solid feed is limited. The optimal amount of milk will vary with a number of factors. For example, under cold conditions, energy requirements increase, as the calves need this energy to generate body heat. Whole milk has a higher protein, fat, and digestible energy content, as well as a better balance of nutrients than some commercial milk replacers. Abrupt changes in diet, use of poor quality milk or milk replacer, and force-feeding of milk are all associated with health risks for the calf, including diarrhea (24).

Environment also has a substantial effect on calf growth. Calves will become cold-stressed at approximately <10°C, requiring additional energy for maintenance and growth (34). Ad libitum nipple feeding of milk to dairy calves can allow for increased milk intake and weight gain with no detrimental effects on intake of solid food after weaning.

RECOMMENDED BEST PRACTICES

1. provide supplemental colostrum feeding even when calves are allowed to suckle from the cow (23)
2. check the quality of colostrum with a colostrometer (23)
3. measure immunoglobulin status in calves and feed colostrum to achieve a blood serum immunoglobulin concentration of 10mg/ml (23)
4. use good hygiene practices when collecting, storing, and feeding colostrum (23)
5. provide whole milk, equivalent milk replacer, or pasteurized waste / discarded milk to calves ad libitum (24)
6. offer milk that is between 15-40°C
7. offer calves a minimum total daily intake of 20% of body weight in whole milk (or equivalent nutrient delivery via milk replacer) until 28 days of age (e.g., approximately eight liters per day for Holstein calves)
8. provide milk via a teat or provide a dry teat after milk feeding to satisfy the calf’s motivation to suck (24)
9. increase milk intake when the environmental temperature drops below 10°C (increase all fluid diets by 25% in winter months)
10. wean calves by gradually reducing their milk over 5-14 days
11. manage group feeding systems to reduce competition between calves (24).