12 January 1996

Dairy ketosis leaps up from 2% to 5%

UP TO 5% of dairy cows are suffering ketosis, compared with a normal level of 2%, according to the latest UK Vet disease profile (see p38).

The metabolic disorder, which hits cows during the first month post-calving, coincides with a marked rise in milk yields.

Cow energy intake fails to meet milk production demands and blood glucose falls due to lack of energy in the diet. The cow has to rely on her body reserves instead. The breakdown of fat that results produces ketones in the blood.

According to Dr Tony Andrews of the Royal Vet College, the first sign of the disease is that the cow becomes sluggish and goes off her food; concentrates first, then hay and silage.

Treatment is via a highly palatable diet, corticosteroids and in some cases glucose.

"To reduce the risk of ketosis," says Dr Andrews, "ensure the cow has capacity to digest high energy diets post-calving by careful management in the dry period."

He advises that cow condition scores should be about 2.5 to 3 during the dry period, as fatter cows are more prone to ketosis. Dry cow feeding regimes should be designed to accustom the cow to the post-calving diet and to ensure the gut has sufficient capacity to accommodate intake levels required.

"Post-calving, energy feeds such as flaked maize can be provided once or twice a day at 1kg a head a day. Exercise will also help," he says.

Keenans Donald Brown believes any producers kept their cows out at grass for too long this autumn. "We advised offering extra straw in the dry period to ensure rumen capacity was sufficient capacity to intake enough energy after calving."