The importance of standardised testing in accurate livestock genetic evaluations

Freek Botes and Melville Ferreira, senior research technicians, and Dr Ben Greyling, research team manager, all of the Agricultural Research Council's Beef Cattle Improvement Scheme, explain why consistency is crucial when calculating estimated breeding values in livestock production. They also review the importance of standardised performance testing procedures.

- 

Over the past couple of years, the beef breeding industry has seen a proliferation of private performance testing service providers for cattle breeders.

We aim to review the importance of the standardised performance testing procedures all testing centres should adhere to, ensuring that the tests done and the data collected are scientifically reliable and will add value to the selection decisions every cattle breeder will make. And that it will also be to the benefit of the national beef industry as a whole.

STANDARDISED TESTING

The primary goal of all performance testing is to produce estimated breeding values (EBVs). To understand why standardised performance testing procedures matter, it is essential to first revisit the concept of EBVs. An EBV is a prediction of an animal's genetic potential to pass on desirable traits to its offspring. EBVs are calculated using performance records and pedigree data, and more recently also include genomic information.

These values are generated through best linear unbiased prediction (BLUP) models. These models separate genetic influences from environmental factors to provide a more accurate measure of an animal's breeding potential. The higher the accuracy of EBVs, the more reliable they are in predicting an animal's genetic contribution to the next generation. This brings us to an important point: adhering to standardised test procedures when collecting data for EBVs is crucial for ensuring the accuracy, reliability, and comparability of genetic evaluations.

The reason is that standardised test procedures in animal performance recording are aimed at identifying and controlling, as far as possible, environmental (non-genetic) effects that may have influenced the performance of a specific animal. This brings us to the principle and aims of constituting contemporary groups.