Colostrum – get the best from that liquid gold
It’s coming to that time again – soon the cows will be calving and the calf sheds will be full of happy, healthy, bright eyed calves. They will have all had a good drink of high quality colostrum soon after birth, and will be well set up to become a great dairy cow. The amount of quality colostrum a calf receives in her first 12 hours of life can affect not only her health to weaning, but growth rates after weaning, and even milk production in first lactation.
The difference between poor and good quality colostrum is hard to spot with the naked eye, but some good guidelines can be followed. Only the very first milking is considered to be true colostrum (the gold stuff), after that it really is transition milk. Colostrum takes 5-6 weeks to produce in the udder pre-calving, and contains high levels of antibodies required by the calf. The best and most practical way to improve colostrum quality is to milk freshly calved cows as soon as possible, as quality declines every hour that the cow is not milked after calving. Generally it is thought that mature cows produce better quality than heifers but this has been disputed! It is possible to measure the quality of colostrum with a simple, cow-side test using a refractometer. This is the only way of really knowing how good it is, and it does make a difference! For an average sized calf to get enough antibodies they need 4 litres of good quality colostrum in the first 12 hours of life, but if it is poor quality they may need up to 6 litres in this time.
Levels of specific antibodies such as those against rotavirus, can be improved by vaccinating cows pre-calving. To get protection from these, and other antibodies (and therefore be able to fight infection), the calf must have a really good drink within 12 hours after birth, preferably within 6 hours. After this time the calf has very limited ability to absorb beneficial antibodies due to “gut closure”. The consequences of poor antibody transfer (failure of passive transfer, FPT) are wide and varied. Most of you will be aware that calves that haven’t had enough colostrum are more prone to diarrhoea/scours, but the effects don’t stop there. Heifer calves with high levels of colostrum intake (4 litres of good quality, in the first 24 hours) are less likely to die before weaning, have a higher average daily weight gain, more milk in their first two lactations, and possibly the best news for farmers is the reduction in vet costs.
Calf management to weaning is such a crucial part of growing a quality cow, and there are many pieces in the puzzle. We can provide on-farm staff training to smooth out the calf rearing season, and also look at ways to improve the systems in place on your farm. If you are using pre-calving vaccines it is important to manage colostrum in a way that maximises the benefit of the vaccine, and we can also provide advice on this.