What is genomics?

Genomics is breeding using DNA (Genotype) to help better predict how well an animal will perform in the future. DNA is passed from parents to offspring and is therefore central to breeding. The DNA profile of an animal is analysed (eartag tissue sample) and is compared to the DNA profiles of older proven animals also known as the reference population and looks for similarities. Performance data, Ancestry data and Genomic data are combined on the animal itself generating a more accurate prediction of the animal’s genetic make-up.

The Science of Genomics

The DNA is the building block of life and therefore it is DNA in combination with management (e.g., feeding) that determines the performance of the animal such as how much milk it will yield, its susceptibility to health and its fertility performance. The DNA of an individual remains the same throughout life. Therefore, by taking an eartag tissue sample from a newborn calf, its DNA profile can be determined and this can be used to predict the subsequent performance of the individual. Because DNA is transmitted from one generation to the next, the DNA of a calf (e.g. Potential bull) can also be used to predict the expected performance of its progeny.

How is the DNA analysed?

Genotypes are made up of Single Nucleotide Polymorphisms (SNPs). These are a DNA sequence variation occurring commonly within a population and each SNP represents a difference in a single DNA building block, called a nucleotide. Different variants are present and have different associations with performance.

The DNA is extracted from the eartag tissue sample and analysed on a SNP Chip. DNA is transmitted in chunks and genomic testing then identifies which DNA chunks have been passed from the parents to its offspring. The genotype is studied to check parentage to confirm that the dam and sire recorded are correct. The genotype is then analysed on animal’s traits such as; milk production, carcass weight etc.

Benefits of Genomics

• Parent verification: A genotyped animal can have its Sire and Dam confirmed
• Higher reliability of genetic indexes: Genotyping increases reliability% figures even before the animal has produced any offspring
• Traceability: Genotyping ensures that from birth there is full traceability of every meat sample

Soon, genomics will allow farmers to avoid inbreeding using genomic mating’s, where relationships between animals are quantified at the genomic level. It will also be used to avoid genetic defects that could arise from mating cows to bulls that are known carriers of genetic defects.