When it comes to breeding the next generation of female replacements on Irish dairy farms, it’s important dairy farmers have a clear breeding policy, as it will have a significant impact on their farm profitability, farm sustainability and animal welfare performance. The use of the ICBF Dairy Active Bull List, Dairy Sire Advice, genomic testing and the HerdPlus service are just some of the tools which can be used to help farmers make more informed breeding decisions to ensure that we produce a more profitable dairy cow for the future.
Dairy Active Bull List
The active bull list is the top 75 dairy AI bulls ranked on the Economic Breeding Index(EBI). The average EBI of the dairy active bull list was €320 in Spring 2024. This is presented in Graph 1. In order to make this list, semen from these bulls must be indicated as being available by the various AI companies, hence the term ‘Active Bull List’. Bulls must have an EBI with a reliability greater than or equal to 35%. Furthermore, they must also have a calving difficulty evaluation with a reliability greater than or equal to 70% (based on 23% heifer rel% and 77% cow rel%) with at least 50 calving records, either in Ireland or in the bull’s country of origin.
When selecting bulls, it is important to note the source of the bulls proofs. Proofs may be based on a bull’s own daughter performance e.g. DP-IRL, or he may be a ‘Genomically Selected’ (GS) bull. ‘Genomically Selected’ means that the Bull’s DNA profile has been analysed, and the EBI figures are based on genomic data. These bulls have their own calving ease proof but not yet proven on the production proof. When deciding to choose daughter-proven or genomic bulls, farmers should use a team of genomics bulls. Analysis has shown that progeny out of genomically selected bulls consistently have higher EBI and deliver better production and fertility than progeny bred by bulls selected on daughter-proven ebvs.
Dairy Sire Advice Application
Sire Advice is an application that is available to all dairy HerdPlus users. The trends in the HerdPlus Sire Advice usage are presented in graph 2. This application allows you to select the bulls you wish to use for the breeding season and match these bulls to the most suitable cows in your herd. The application allows users to do this in one of three ways:
- Suggested Bulls (75 bulls from the ‘Active Bull List’) – Select bulls exclusively from the current ‘Active Bull List’.
- Select Bulls Using Traits – Narrow your selection of bulls by entering ranges for particular traits of importance for your herd e.g. you may only want bulls above a certain % on protein. This function also includes a female selector where females can be selected for culling, beef mating, crossbred mating, and selective mating.
- Manually Enter Bulls – If you have already selected your team of bulls you can simply enter these bulls and run the application.
When sire selection is complete, the application then checks selected sires against cows in the herd for potential inbreeding. The application then matches sires to cows by reducing the difference between the milk and fertility sub-indices. For example, a cow with a poor fertility sub-index would be allocated the highest fertility sire, to breed a more balanced offspring. This application helps to accelerate genetic gain by matching the selected bulls with the most suitable cows.
Genotyping Dairy females
The Genomic testing of dairy female continues to become increasingly popular amongst dairy farmers, largely with the introduction of the National Genotyping Programme in 2023. The programme has further improved the uptake of genotyping on dairy farms with a third of the national Dairy herd now genotyped. This can be seen in graph 3 with the number of dairy females genotyped each year.
Genomic evaluations use the DNA profile of an animal to help better predict how an animal will perform in the future. 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.
Genotyping generates a wealth of information that will help to make better breeding decisions. There are many benefits to be gained from genotyping females, such as the parentage verification and providing a better prediction of the true value of an animal’s genetics. 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 a better selection of herd replacements.
Dairy HerdPlus Membership
HerdPlus is ICBF’s farmer information service, which provides herd-owners with performance data which can be used to make more informed breeding and management decisions. HerdPlus uses data from many different sources including animal events data, AI data, milk recording data, etc. HerdPlus then compiles this data into various useful profiles, reports and applications including Sire Advice, EBI reports, Milk Recording reports, etc. The reports benefit both management and genetics. The table below shows the performance of HerdPlus versus non-HerdPlus dairy herds. The analysis clearly demonstrates that HerdPlus herds are outperforming non-HerdPlus herds across the different key performance indicators. For the fertility performance, the HerdPlus herds had 16 days shorter calving interval, a 10% better six-week calving rate and a 21% higher percentage of heifers calving down at the optimum age. For the milk performance, HerdPlus herds had a 50kg better milk solids per cow and 48k lower somatic cell count.
Economic Breeding Index Validation
Analysis carried out by ICBF on 14,142 manufacturing milk herds has shown that higher EBI herds are more profitable and produce less GHG emissions compared to the lower EBI herds. This is presented in Table 2. The table clearly shows how varying levels of herd EBI impacts the 2023 farm performance but also the carbon footprint of the national dairy herd. The top 20% and the average EBI herds have an EBI of €196 and €153 respectively. The top 20% herds produced 0.07 kg less milk carbon emissions per year, compared to the average EBI herd. There is also a higher percentage of herds engaged in milking recording and signed up to HerdPlus in the top 20% compared to the average EBI herd. When comparing the milk performance of the top 20% of herds on EBI to the average EBI herd, the top 20% had 442 higher litres per cow, 53kg better milk solid per cow and 47k lower somatic cell count. For the fertility performance, the top 20% of herds had 12% better six-week calving rate, 16 days shorter calving interval and a 35% higher percentage of AI bred replacements compared to the average herd EBI.
Summary
Farmers can only make fully informed decisions when using all of the technology and information at their disposal. Selecting bulls from the ICBF ‘Active Bull List’ will ensure that farmers select the best available genetics from which to breed future cows. Utilizing the HerdPlus service will allow farmers easy access to vital performance data to make more informed decisions. Sire Advice will help to breed more balanced cows by matching cows to the most suitable bulls, and genotyping your dairy replacements will help identify the best heifers for breeding replacements. Research continues to show that EBI delivers on the ground for Irish farmers.