27 July 2001

High yields mean reduced fertility

HIGH yields can only be achieved at the expense of a reduction in herd fertility, according to recent research at the Royal Vet College.

Cows producing peak yields of greater than 42kg/day took four weeks longer to conceive than those producing under 42kg/day, Claire Wathes, a researcher at the college, told the British Cattle Vet Association meeting.

Mean calving to conception interval for cows peaking at more than 42kg a day was 114 days compared with 82 days for those peaking at less than this amount.

"In cows on current UK diets, high peak yields can only be achieved at the expense of a reduction in herd fertility," said Prof Wathes.

&#8226 For a full report on the meeting, turn to page 42. &#42