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 (hair 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 (Economic Breeding Index).
The Science of Genomics
The DNA is the building block of life and therefore 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 a hair 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 hair follicles 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& Dam confirmed
- Higher reliability figures: Genotyping increases reliability% figures even before the animal has produced any offspring
- Genetic defects: An animal’s carrier status for a number of diseases and major genes (e.g. Myostatin) is also possible
- Gene Identification: Polled gene and whether an animal is homozygous or heterozygous
- Breed verification: Genotyping will be able to identify an animal’s breed makeup.
- 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.
With traditional breeding - for an animal's figures to become more accurate, you must wait until it expresses its genes through its progeny. With Genomics, an animal's genes are analysed and more accurate figures can be calculated at birth.
Roundhill Polled Limousins
The entire herd at Roundhill is genotyped. Each calf is genotyped at birth to ensure accuracy of its ancestry.
This ensures that:
- Each animal has its pedigree verified at birth.
- Purchasers can subsequently validate all the progeny from their purchased animal.
- Purchasers have the confidence of increased reliability of the indexes.
- The polled gene can be identified and whether it is a homozygous or a heterozygous carrier.
- Other major genes can be identified e.g. mh+ ge
