10 May 2002

Concern voiced over conception

MILK producers in the UK should be concerned when after two breeding cycles just 52% of maiden heifers, the most fertile animals on the farm, are in calf.

Australian Practice into Profit grazing consultant Tom Phillips explains that heifers do not have the stresses of walking miles to grazings and producing milk, but submission rates are unacceptably low.

"In Australia, 75% of cows and heifers are pregnant at six weeks and UK producers should see this performance as a benchmark," he says.

They needed to seek reasons for poor results. In the case of heifers it could be low bull power. He knew of one farm where one sire was expected to serve 60 heifers, when the correct ratio was one bull to 20 heifers.

To ensure cycling, heifers needed to be fully grown and properly fed. On some farms heat detection was inadequate, on others the AI system could be at fault. Whatever the reasons, herd managers had to look closely at breeding performance and put things right. &#42