29 November 1996

House those dry cows ASAP

DAIRY producers running dry cows outside in late pregnancy could be compromising future fertility and milk performance.

The warning, from the Dalgety Herd Health and Productivity Service, is in response to blood test results highlighting energy deficits in cows close to calving.

"Blood tests are showing energy deficits on virtually every farm where these animals are still outside," says DHHPS vet David Whitaker. The service has also recorded energy deficits when silage and concentrates are being offered in the field.

The condition is caused by the drop in appetite in the last weeks before calving, coinciding with the poor weather, which has increased energy requirements, explains Dr Whitaker.

"Fat mobilised as an energy source has to pass through the liver to be converted to glucose. When mobilisation is excessive, it can damage the liver. Liver function can be affected and as a result milk and protein production fall."

Dr Whitaker advises these dry cows are housed as soon as possible and suggests that condition scoring alone might not provide enough detail on potential harmful metabolic changes inside the cow. &#42