Fertility and milk solids are the focus for bull selection for the UCD research farm at Lyons, according to Dr Karina Pierce. The 100-cow herd produces liquid milk and is managed as a split herd, with approximately 40 autumn-calving cows and 60 spring-calving cows.
"It's a Holstein Friesian herd and our focus is on fertility and solids but we have to maintain some focus on yield," explains Dr Pierce.
"We always keep an eye on conformation and traits like teat length. We try to select a team of five or six bulls, with about two genomic bulls in the mix," she says.
"We also have quite a lot of OJI blood in younger stock so we need to select non-OJI bulls as well," she adds.
Bull selection for the coming breeding season has not yet been finalised but it will be along similar lines to the autumn bull selection, she says.
Approximately 30pc of the autumn calving cows were inseminated with the bull GJM from AI company ABS. This genomic bull had an EBI of €245 and was chosen as a sire with a good split between milk sub index and fertility traits.
KXV, the top-ranked bull of autumn 2011, was used on 20pc of the herd. With an EBI of €265, this Dovea bull was chosen for his high fertility traits and used on the highest milk yield cows.
Another 20pc of the herd was inseminated with AYW, a genomically selected bull from Dovea. With an EBI of €239, he was also used on the higher milk yield cows, primarily because of his high fertility sub index.
The internationally daughter-proven ABS bull VGE was used on another 20pc of the herd. With an EBI of €211, the bull was chosen for his balance between milk production and fertility traits.
Finally, the Irish-proven NFT from the National Cattle Breeding Centre was used on OJI daughters and cows with very high milk yields. He had an EBI of €213.