Using Commercial Data and Genomics to Improve Female Fertility and Calf Survival of Limousin beef cattle in the UK

Improving female fertility (FF) and calf survival (CS) in the beef suckler herd will result in more calves reared, increased beef production and a reduction in greenhouse gas emissions per output. To date there has been little improvement in these traits with the industry focused primarily on terminal traits coupled with inadequate or absent selection tools available for fertility and survival. This has been to due to the low accuracy at the time of bull selection of conventional FF estimated breeding values (EBVs) and that previously there have been no CS selection tools. National UK data was used to produce genomic EBVs (GEBVs) for CS and FF traits" age at first calf, calving interval and lifespan. The data showed that on a national level the largest number of heifers calved as three year olds, average first calving interval was 424 days, only 47% of cows had more than three calves in a lifetime and 5% of calves do not survive past 10 months of age. These findings were common across a number of different UK beef breeds. The traits were found to be lowly heritable with heritabilities ranging from 0.04 for CS to 0.13 for age at first calf. The resulting genetic trends showed that there has been no genetic improvement in these traits across the beef industry. Comparing the fertility and survival trait GEBVs with existing video image analysis (VIA) abattoir carcass trait GEBVs showed small to moderate antagonistic relationships between the carcass and fertility traits.