Pin bone-fertility link dismissed

HIGH PIN bones in dairy cows, measured as rump angle, are not linked with poor fertility, concludes research at SAC Edinburgh.

Rump angle is well known for its relationship with calving difficulty, because the calf has to come up into the cervix, researcher Eileen Wall told delegates.

 There is also a relationship between rump angle and culling rate at both extremes of the scale.

“But some breeders and vets also believe animals with high pin bones will have poor fertility, because of the angle.”

 Dr Wall used data from 29,000 Holstein UK classified cows to investigate any possible relationship between rump angle and fertility to see whether it could be used as a fertility indicator.

 She found a small relationship between calving interval and fertility, but there was no relationship with non-return rate or other fertility traits. “So there is no optimum rump angle for fertility,” she concluded.