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11 May 2022

Genomic testing is much more than just breeding values

Today, more and more farmers are interested in testing their heifers genomically. Genomic breeding values have higher reliability compared to parent average breeding values, which is useful in mating programs to do better matches of females and bulls.

However, there are more benefits of genomic testing that can be used in mating programs.

The interest in genomic testing is growing among dairy farmers worldwide. Besides more accurate breeding values, farmers who genomically test their females get information about which animals are carriers of genetic defects.

That information can be used in mating programs to avoid the matings where both a female and bull who are carriers of the same genetic defect.

Most of the genetic defects we know today are recessive, which means that if two carriers of the same genetic defect are mated, one-fourth of the pregnancies will be affected, leading most commonly to an abortion of the pregnancy.

That is why it is of economic importance for the farmers to avoid matings where both individuals are carriers of the same genetic defect.

Genomic testing also offers the possibility to calculate genomic relationships between mating candidates. Genomic estimates of relationships are more accurate than pedigree information because they do not rely on pedigree completeness or correctness.

Besides that, genomic estimates of relationships can differentiate between animals with the same pedigree relationship, for example, full siblings, who inherited partly different genetic variants from their parents.


Study: Mating allocations in Nordic Red Dairy Cattle using genomic information

In a collaboration between the Swedish University of Agricultural Sciences and VikingGenetics, scientists investigated how to combine all new information best when making mating plans.

They created different economic scores within each herd, considering:

  • genetic level
  • semen cost
  • the economic impact of recessive genetic defects
  • genetic relationships

In the study published in the Journal of Dairy Science, Feb. 2022 researchers compared traditional mating plans without genomic information with mating plans where the new genomic information was included. All economic scores were optimized at herd level.

In total, mating plans were made for almost 10,000 VikingRed females, and 50 VikingRed bulls were available for inseminations.

In total, six genetic recessive genetic defects were considered. Every bull could to a maximum be mated to five percent of the females in a single herd.


The mating results showed that it was possible to reduce the different genetic relationships between parents with minimal effect on the genetic level.

Including the cost of known recessive genetic defects eliminated expression of genetic defects. Hence, it was never economically beneficial to mate two individuals carrying the same genetic defect.



Optimized on:

Genetic level

Genetic level +  Pedigree relationship

Genetic level +  Pedigree relationship + Costs of genetic defects

Genetic level +  Genomic relationship + Costs of genetic defects

Genetic level (NTM)





Pedigree relationship





Genomic relationship





Expression of genetic defects







The study showed that it was possible to reduce genomic relationships between parents with pedigree measures, but it was best done with genomic measures.

The results illustrate the many benefits of genomic testing, especially for the individual farmer at the herd level.

All results can be found at:


Text by: Christian Bengtsson, PhD student at the Swedish University of Agriculture (SLU)

Read more about VikingRed here Red Dairy Cattle