Breeding dairy cows using genomics for an improved dairy herd
With the introduction of cattle genotyping in 2008, breeding animals for both dairy and beef may seem to have become rather more complicated for farmers. Not only is there an implication that they must understand the science of genetics but they are also required to understand and process genetic data in order to make informed choices on improving the genetic merit of a dairy or beef herd. The National Bovine Data Centre (NBDC) acts as a knowledge resource to assist breeders and farmers with the science of genomics for both breeding and management. The data produced can be divided into two categories, phenotype and genotype and we look at these here.
Phenotypes for improved management decisions
Phenotypes inform the farmer as to a cow’s actual performance. For example, if a dairy cow produces a lot of milk and is trouble free and healthy, then it should be kept in the herd regardless as to its actual genetic merit. Phenotyping assists the farmer to make herd management decisions which may include specific feeding regimes, a farm’s culling policy and all round animal husbandry and necessary welfare issues. Without this data, it is down to each individual farmer to make decisions based upon knowledge and experience rather than underpinned by hard facts.
Genetics for breeding dairy cows
Genotyping, or using genetic data to inform breeding choices, is concerned with the genetic merit of an animal and should be used to assist in the selection of a breeding bull as well as the dam. In order to be profitable, farmers need to breed new stock that will perform well in an average dairy herd and selecting breeding dairy stock that fit performance standards can thus be enhanced with the use of genotyping.
Performance in dairy cows can be altered by the way in which they are managed but the use of phenotype and genotype data removes these effects from the equation helping to give a far clearer picture as to how a cow will perform and making breeding dairy cows simpler.
Accessing the Breeding Toolbox
The National Bovine Data Centre publishes genetic evaluation data regularly, and for 2017 the publication dates are Tuesday, August 8 and Tuesday, December 5. The centre has also developed a suite of software which can assist with breeding dairy stock to ensure that future generations of dairy cattle have increased genetic merit, which in turn leads to improved profitability. This information is accessed via the NBDC’s Breeding Toolbox.