Autumn-calving
As autumn-calving herds build towards the start of the calving season, it is important to remember the role that colostrum plays in disease control within young calves. As the immune system of the calf is not fully developed until three weeks-of-age, passive immunity is required in the form of quality colostrum from the cow.Because of this, colostrum management is the single most important factor in determining calf survival and subsequent health.
Calves should be given clean, high quality colostrum by a stomach tube or a bottle. A calf requires about 10% of their birth weight in colostrum, which is usually between 3L and 5L. Calves should receive this colostrum within the first two hours of life for optimum absorption of antibodies. Over the first six hours of their life, the calf’s ability to absorb antibodies from the gut is very high. However, as time passes this declines; to 50% within 12 hours of birth, 25% within 18 hours and only 10% within 24 hours.Colostrum management
The treatment of sick calves is time consuming and can be expensive. It can also be annoying when calves do get sick after you have done everything right. The issue may not be the amount of colostrum being provided, rather the quality of the colostrum.Colostrum quality can be tested using a Brix refractometer. High-quality colostrum which has a reading of 22% or above on the refractometer can be used or stored.
The colostrum quality in a first calved heifer may not be as good as a second or third-calver. A cow's colostrum quality generally peaks around their third or fourth lactation, with the quality decreasing after this. This is why the testing of colostrum is important, to ensure that calves are receiving a high-quality first feed.Disease control
Having a hygiene plan in place is critical for the prevention of disease and infection management in calves. You should make sure calf pens and milk feeding equipment is thoroughly cleaned and disinfected between feeds.Entry to the calf shed should be controlled, there should be a disinfection point at the entrance to the shed and farmers should avoid wearing dirty clothes into the shed.
In herds where Johne's disease is, or may be an issue, the pooling of colostrum should be avoided - this is to help to control the spread of Johne's within the herd. The use of vaccinations are an effective way to boost a calf's ability to combat disease and will become increasingly more important after January 2022. In conjunction with your vet, a vaccination programme for your herd should be developed to suit your herd's needs.