Colostrum – the key to good calf rearing

Each calf is born without immunity to disease and must instead absorb antibodies from colostrum. Absorption of antibodies is fastest in the first few hours of life, then slows and eventually stops by the time they are 24 hours old. Interestingly, many calves (studies have shown up to 50%) will not get enough colostrum when left to feed just from their dam, and it is not possible to tell from gut fill which calves have had enough colostrum. This is why we recommend collecting calves twice a day and feeding or tubing all calves with colostrum as soon as they have been collected. 

Ideally, a 40kgm calf should receive two feeds of two litres of colostrum within the first 12 hours of life. Calves typically need 10-15% of their bodyweight in colostrum each day for at least the first four days of life and preferably the first three to four weeks. The benefits of feeding it, even after gut closure, are evident as the antibodies have a protective local effect in the gut.

Good quality colostrum has high levels of antibodies and low levels of bacteria, as bacteria interfere with the absorption of antibodies. Milking cows ASAP after calving is important, as the amount of antibodies in the colostrum decreases in the hours following calving. 

You cannot reliably tell the quality of each cow’s colostrum from the outside, so the best way to know if colostrum is good quality is to test each cow before her colostrum is fed to newborns. This can be done instantly on farm using a BRIX refractometer. Colostrum from a mastitis cow or with blood in it should not be fed. Vaccinating cows with products such as Scourguard® 4K or Rotavec Corona® increase antibody levels in colostrum and ensure it contains antibodies to help control infectious scours.

To keep bacterial levels low, it is crucial to think about hygiene at each step of the process; clean udders, clean storage buckets with lids, and clean calf feeders. Also, bacteria levels increase rapidly when colostrum is stored for more than one hour, so any colostrum being stored for feeding should be preserved with potassium sorbate. See more information here…

If you would like further information on this or to discuss your calf rearing and management, don’t hesitate to call your veterinarian.