In order to make selection decisions the livestock breeder needs to be able to accurately assess the genetic merit or ‘breeding value’ of their stock. The visual assessment of an animal, often combined with some information about its performance and/or the performance of its close relatives, can be a useful guide.

However, because the performance of all animals is influenced by both genetic and non-genetic factors such as feeding, disease, climate and management, selection ‘by eye’ can be misleading. Consequently, until fairly recently, the genetic potential of animals could only be objectively compared if they were living in the same environment and being managed in the same way. 

The development of powerful computers and sophisticated software in the form of BLUP (Best Linear Unbiased Predictor) has made it possible to disentangle the genetic from the environmental effects on the performance of pure-bred animals allowing animals in different herds to be directly compared. Purebred beef animals constitute only a small proportion of the beef cattle population of Britain but they have an essential role to play in the production of high genetic merit breeding bulls. These bulls are then used widely in commercial herds, thus disseminating genetic improvement throughout the national herd.

Signet’s Beefbreeder service for pedigree breeders collects data on individual animals within a herd, which is then analysed using Best Linear Unbiased Predictor (BLUP). The BLUP procedure produces Estimated Breeding Values (EBVs) for each animal for each recorded trait. They are estimates of the genetic worth of the animal. They have the same unit as the recorded traits and are expressed relative to a common baseline for all animals in all contemporary groups. For all breeds in the UK the baseline is set so that the average of the breeding values for animals born in 1980 is zero. 

The EBVs calculated to date are:-  
  • Gestation Length
  • Calving Ease
  • Birth Weight
  • 200 Day Milk
  • 200 Day Growth
  • 400 Day Growth
  • Muscling Score
  • Muscle Depth
  • Fat Depth

Two economically weighted indexes Beef Value and Calving Value are calculated from these EBVs. These two indexes allow trade-offs to be made between the amount of selection placed on calving traits and those placed on growth and carcase traits.Beefbreeder EBVs and Values, as well as your own stock judgement and sound management policies, should ensure progressive genetic improvement.