11 September 1998

Fertility data should be noted

FERTILITY is of economic importance to dairy producers, but few UK breeding indices include it. Researcher John Woolliams of the Edinburgh-based Roslin Institute, suggests that better recording on-farm could change that.

He told delegates that the UK lags behind other countries in recording fertility performance. In the US, bulls are listed according to AI conception data.

PIN and ITEM indices for bulls means producers are not told about sire fertility by breeding companies, while increasing Holstein influence means conception rates are slipping to 50%.

"This data is hard to collate in a reliable format, as it usually hides environmental influences, such as culling policies, and is normally collated from visual observation," said Mr Woolliams.

To benefit, producers should start to record reproductive data, including days to first service, conception rates and calving intervals, as well as details which influence culling policy, fertility treatment and inseminations, he said.

Kevin OFarrell, researcher at Teasgascs Moorepark dairying centre, Ireland, added that breeding companies should provide fertility indices to make sire evaluation more thorough. "Heritability of this trait is less than 10%, but any improvement would be both beneficial and cumulative."

To do this, Mr Woolliams suggested increasing numbers of test daughters from each bull would provide more data and overcome lack of heritability data.