Genetic testing to improve the cattle and dairy herd

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Genetic testing to improve the cattle and dairy herd

August 03, 2022

Thermo Fisher Scientific explains the value of genetic testing for livestock using genetic selection, phenotype selection, and paternity testing

Genetic testing technology is advancing rapidly. Tools such as AgriSeq targeted solutions from the Thermo Fisher Scientific agrigenomics portfolio accelerate genetic breeding decisions by providing accurate, high-throughput data on an individual animal’s value. Breeders and producers can take advantage of these developments by focusing on the herd’s specific needs to select economically relevant traits (ERTs) to improve animal value and profitability.

Genetic breeding programs use a variety of methods to determine an animal’s value. They all depend on the identification of molecular markers that predict or correlate with a particular trait or phenotype. Tests that use single nucleotide polymorphism (SNP) detection, which identifies genetic variations associated with conditions such as coat color, double muscle or disease, are increasingly popular because of their speed. It is possible to process 100s of samples for 1000s of SNPs in a single sequence, and get the results within a few days.

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There are three main areas in which genetic testing is valuable in livestock:

  • Genetic selection for high-value production traits
  • Choice of phenotype, for consumer preference or to avoid disease
  • Paternity test for animal identification and herd management

genetic selection

Genetic selection relies on identifying traits associated with ERTs as well as expected offspring differences (EPDs) that improve animal value, for both breeding and production potential. Sons’ selection for a dairy herd may focus, for example, on traits of a daughter’s value such as milk production. Molecular markers of greater scrotal circumference in newborns predict early puberty in girls. In beef production, traits like mature weight, higher and more efficient feed conversion rates are more desirable.

Wisely using genetic selection tools can increase the profitability of the herd. Being able to identify animals that have better milk production, weaning weight and muscle characteristics for example will produce a better end product for the market.

However, in order to drive the herd forward, producers must take care to select traits that improve profitability rather than increase costs. Choosing for example fast growth or higher milk yield will not improve production where nutrient or feed quality is a limiting factor. Taking into account herd goals within environmental and breeding constraints will maximize benefits and avoid obstacles to achieving full performance potential.

Trait testing for phenotype selection

Molecular markers that correlate with specific phenotypes can be useful for predicting origins of production (intramuscular fat marbling), cosmetic factors (red or black coat of consumer preference) and disease susceptibility (enzyme defects such as mannosidase deficiency in Angus animals).

Since some cases are inherited in a recessive manner, it is important for breeders to identify heterozygous individuals as carriers within the herd or breeding environment. These can include cosmetic traits such as coat color, and more harmful mutations that cause disease or disfigurement.

Cosmetic phenotypes can have an effect under certain breeding systems. For example, cattle with albinism have an increased sensitivity to light, and white-faced animals also experience an increased risk of skin diseases including cancer around the eyes. Hereford and similar breeders may select animals that have “goggles” – dark hair color and pigment around the eyes – although the genes for this phenotype have not been fully identified.

Some signs of a visible phenotype are also good indicators of cryptic malformation. An example of this is White Cow Disease where the white coat color of the Belgian Blue and Shorthorn animals is associated with the failure of the female reproductive system to develop fully. Infected animals are usually sterile. Since this is not externally obvious or easy to detect under some herd management systems, it may be a cause of overall poor flock fertility.

paternity test

Pedigree testing is based on genetic assessment using polymorphisms or other molecular markers to exclude individuals based on simple heredity.

Under some management situations, paternity may not be immediately apparent. Genetic evaluation of offspring against all potential parents can determine whether a calf is the result of artificial intelligence or natural service under certain herd management systems. This is also a useful tool where the producer does not notice the service, in situations where many bulls are running with the herd.

Genetic testing is also valuable in determining the lineage of valuable animals before and after sale, to confirm identity. It can also be used by producers to confirm transmission of offspring.

Find out more about genetic breeding software solutions from Thermo Fisher Scientific Agrigenomics

If you would like to see how these tools can help your breeding program, sign up for a free consultation with one of our experts.

For research use only. Not for use in diagnostic procedures.