With the 2020 breeding season on the horizon, now is a good time to look back at the previous breeding season. Below, we display the top 10 AI bulls used in 2019 based on the data recorded on the ICBF database.
The total number of serves recorded in 2019 was 855,859 which is approximately 6% ahead of 2018. The sires in Table 1 make up 33% of all dairy serves. Their level of usage suggests that farmers are opting for high EBI when selecting bulls for the breeding season and using the index to drive genetic gain thus maximising profitability through genetics.
In Table 2 we can see that as a team they have an average EBI of €250 between them, with an average milk sub index of €87. On the Fertility sub index, they have a team average of €105. As a team they have a good balance between milk and fertility. Fertility is crucial in a grass-based system as we need a compact calving season to match the grass growth curve to produce as much milk as possible from grass.
On the maintenance sub index, they have an average of €12. These bulls with a positive maintenance figure tend to have better feed efficiency and have lower live weights. As a result, they require less feed to meet their maintenance requirement for energy.
The health sub index for this group is positive also with an average index of €4. This sub index includes lameness, SCC and Mastitis. This sub index is important as having a herd with reduced instances of lameness and mastitis should reduce instances of culling. To maximise profitability per cow, cows need to achieve 5.5 lactations while currently they are only lasting 4.4 lactations on average in herds.
These bulls went through the Dairy Gene Ireland programme which highlights the success of the programme for testing and getting these young high genetic merit bulls onto the active bull list for widespread use.
Based on the top 10 bulls used farmers are opting for both high EBI daughter proven bulls and genomic sires. Some farmers are concerned about using genomic sires due to their lower reliabilities. When farmers select a team of bulls, they can spread some of the risk associated with using genomic sires. It is important to use the bulls evenly when farmers select their bulls to minimise the risk as much as possible. Both genomic and daughter proven bulls can increase or decrease on the EBI.
The genomic sires have higher EBI’s compared to well proven sires which means that when used as part of a bull team the risk can be minimised while maximising genetic gain. Selecting these high EBI young bulls can help drive profitability as every €1 increase in EBI can result in an increase of €2 in profit based on Teagasc Research.