22 September 1995

Acritical time for the calver

THE two weeks either side of calving are the most critical in the dairy cows year.

Cheshire-based dairy vet Neil Howie told visitors to the European Dairy Events Feeding Forum this week that management during this period would determine performance and fertility in the next lactation.

"An easy calving and a good start to lactation are essential for dairying profits," he said.

Cows at condition score 3.0 or greater at calving had more reproductive difficulties, milk fever and mastitis than those calving at 2.5 or lower. But at condition scores below 1.5 fertility was reduced.

Mr Howie said condition score should be maintained at about 2.5 in the dry period. "Dry cows need adequate intakes of quality protein, fibre as belly fill, minerals, vitamins and a positive energy balance," he said.

It was also important to introduce the milking ration 10-14 days pre-calving.

"Cows which undergo the transition from dry to milking without difficulties are more likely to return to pregnancy on time at less cost than those which cause problems at or around calving," he said.

Cows overfat at calving were prone to fatty liver syndrome. Fat mobilisation released ketones which caused ketosis and reduced fertility.

Mr Howie cited Swedish research to show that cows with ketosis one month after calving were twice as likely to have cystic ovaries and their incidence increases four-fold for cows with ketosis two months after calving.

lDairy Event report next week.