19 December 1997

MLC newcalving ease index concerns

UK BEEF producers are concerned that the MLCs new evaluation for calving ease is failing to reflect performance on farm.

Yorks beef producer Richard Fuller of the JSRcalving group, says the new calving value index – which combines birthweight with calving ease and gestation length traits – does not reflect on-farm calving experience with calving difficulties.

"Bulls which we know are easy calving are coming out with negative values – one of our own Charolais bulls which is very easy calving scores -10 for calving ease."

Aberdeenshire Limousin breeder Mike Massie has been shocked by the new calving ease values, after discovering that one of his animals had a value of -16. "We havent had any problems with calving. As the Limousin is known to be easy calving, I cant understand why the values are so low."

Chief executive of the Charolais Society, David Benson, is sure the concept of having calving ease figures is right, but presentation wrong.

"The figures are making bulls out to have serious calving problems when they do not. We have easy calving bulls with values of -10 and -12, and I cannot see how the average can be -2."

Concern over the negative figures means the Charolais Society plans to give only birthweight and production values at early spring sales. "We will look at presentation of the others – gestation length, calving ease and calving value – later in the spring."

Mr Benson would also like to see the figures presented as percentages. "This would be more user friendly, and bulls would still remain ranked correctly within the breed."

One industry source suggested that Signet had set the base too low, hence the prevalence of negative values.

Mr Fuller, a member of the beef breeding forum, formerly the BLUP advisory group, says the calculation for the calving ease trait was weighted too heavily against difficult calving. "That was our decision – but we didnt appreciate the effect it would have. Calving ease figures should have been compared with performance on farm before they were released."

Responding to breeders and societies concerns, Signet general manager John Southgate explains that the reaction to the new calving values was discussed at a meeting of the beef breeding forum.

"No one doubts the accuracy of the data, but concern was expressed about the wide range of calving ease figures."

According to Mr Southgate, Signet and breed societies are currently reviewing calving ease, with a view to reducing the range of values used. Mr Southgate stresses that this would not re-rank bulls. If values are recalculated, they are likely to be re-issued in the next evaluation.

CALVINGEASETRAIT

&#8226 Doesnt reflect performance on farm

&#8226 Range of values too wide

&#8226 Figure to be revised