Application of Genomics on Dairy Farms

Genomics has contributed significantly to the increased rate of genetic gain within the Irish dairy cow population and has transformed how the Dairy Gene Ireland breeding programme operates. Genomic selection (GS) is a tool to help more accurately identify genetic elite animals. This technology combines the DNA profile of an animal with their ancestry and own performance information to increase the EBI accuracy of an animal at a younger age. Many Farmers now see the use of genomically selected bulls and genotyping females as an essential part of running their dairy farm.

Usage of Genomic selected bulls 2021

Over 73% of the dairy inseminations during the first 6 months of the year have been to young genomically selected (GS) bulls. This can be seen in Table 1. The results are based on analysis of insemination data collected from AI technicians linked to the ICBF database, through their AI handheld system. A total of 662,622, inseminations were included in the analysis. Table 1 contains the details of the number of inseminations from GS bulls compared to daughter proven (DP) bulls. The large uptake of GS bulls can be attributed to the difference genetic merit between these bulls and the daughter proven bulls. The average EBI of the GS bulls is €64 and €69 more than the Irish Daughter proven bulls (DP-IRL) and the International Daughter proven bulls (DP-INT) respectively.

The analysis clearly highlights that, farmers continue to have increased confidence in the young GS bulls to deliver more profitability on their farms in the future.

Table 1. Count & Percent of inseminations, average EBI and reliability for daughter proven and genomically selected bulls.

Benefits of Genotyping Females

Genotyping has many benefits at both farm and industry level. At Farm level, this technology will help to decide which heifers to keep or sell. Animals can increase or decrease in EBI so within a group there can be a wide variation of results. Most animals move between -/+ €40 from the parent average. At extremes, this can be in the order of -/+ €100. Having genomic EBI’s for heifers will also help to secure higher sale prices for surplus heifers. The increase in reliability of a genomic proof over the parent average is between 20% to 30%, which is an equivalent to around 15 daughters in milk production.

The genomic information can also verify the parentage and identify incorrectly recorded parentage. This is particularly useful for herds with large number of calves being born over short periods, where it can be difficult to work out the correct sire and dam of the calf. The rate of parentage errors is 15% of all genotyped animals. Genetically elite animals identified will also be of interest to AI companies for the Gene Ireland Breeding programme, looking for suitable cows from which to purchase male calves.

Genotyping generates an abundance of information which will help to make better management and breeding decisions. The current cost of genotyping is €22 per female, which is substantially cheaper than other countries where genotyping can cost up to €90 per animal. The best way of profiting from genotyping females is to select females for replacements based on genomic results over parent average derived breeding values. The cost of genotyping can be recouped through better selection of herd replacements.

At industry level, genotyped females will improve the reliability of genomic evaluations for dairy animals. These females will eventually go on to be used in the reference population for genomic evaluations once they start to gain performance information. As the number of bulls per year remains relatively low, the importance of including females in the reference population will continue to increase, which means it is important that female genotyping at farm level increases as well. Graph 1 shows the total number of dairy females genotyped in the ICBF database. At the end of last year, there was 113,208 genotyped females on the database. Genomic evaluations are also available for multiple dairy breeds such as Jerseys and Norwegian Reds, which will further increase the uptake of genotyping on dairy farms into the future.

Graph 1. Number of dairy female genotypes in the ICBF at the end of each year 2016-2020

In the future, genomics will allow farmers to avoid inbreeding using genomic mating’s, where relationships between animals are measured at the genomic level. The Teagasc next generation herd that represents the future national dairy herd is closely linked to genomics and is crucial for the development of genomic predictions for new traits related to health and the environmental footprint. DNA registration on a national level, which is genotyping at birth, would have significant benefits for Irish farmers and Irish Ag food industries.

How to genotype?

Farmers can order hair kits online by logging into their HerdPlus account. Hair follicles are taken from the tail end of the individual animal and placed in this DNA kit. The Genomic results can be viewed quickly and easily on a genomic evaluation profile. A detailed genomic evaluation report will also be available to view on the reports section of the website. For further queries call the ICBF HerdPlus team on 023 8820452. 

In short

  • Genotyping your dairy replacements will help to identify the best heifers for breeding replacements.
  • With the use of genomic selection of females on-farm now increasing, genetic gain in the Irish national dairy herd is set to increase even further.
  • Use a team of high EBI GS bulls equally on your herd to maximise genetic gain.
  • Genomics is playing a key role on the economic and environmental sustainability of Irish dairy farms now and into the future.