Breeding indexes of dairy cattle that are based on parent averages can change considerably after genomic testing is carried out, Richard Miller from National Milk Records (NMR), told farmers at an event in Drumahoe last week.

Speaking at the NMR open day on the farm of Stephen and Mark Montgomery, Miller said that the traditional method of calculating £PLI breeding indexes based on parent averages was not an accurate way of identifying the best breeding animals in a herd.