The latest economic breeding evaluations have been released by the Irish Cattle Breeding Federation (ICBF) and after some analysis, it raises the question – have we comprised health for fertility?
The overall fertility of the national dairy has dramatically increased over recent years, with the national calving interval reducing greatly.
Based on current performance, by 2031, the fertility issue within the national dairy herd should be solved, with cows calving every 365 days.
Cow health
Recently Siobhan Ring, a geneticist from the ICBF spoke at the European Holstein and Red Holstein Conference, hosted by the Irish Holstein Friesian Association (IHFA) in Dublin.
She told the crowd in attendance that the new focus for Irish dairy farmers should be on improving the health sub-index of their cows.
But by focusing on fertility and production, have we gone too far and created a major challenge for us to overcome?
The issue around Kilfeacle Pivotal and the number of his progeny within artificial insemination (AI) stations has been highlighted in the past.
But if the focus is on health going forward, as is being advised by ICBF, why is bull that is -€7 for health, being used to sire incoming bulls?
He performs well in other areas and many of his progeny have a good health sub-index currently, but they might change when more data becomes available.
Sub-index
When you look within his health sub-index you can see that he performs poorly across all five traits included within the index, with his rating for lameness, mastitis and somatic cell count (SCC) all being poor.
But the worrying trait for many, within the health sub-index, will be bovine tuberculosis (TB); the fact that he places in the bottom 1% to TB resistance with a reliability of 96%.
This surely has to be concerning to farmers that have used Pivotal and are in areas were TB is quite prevalent.
Looking more closely at the data available for Pivotal, his progeny has a TB reactor rate of 5% compared to their herd mates of 4%.
Remember, Pivotal was born in 2018, the first straws were used in 2019 and the first calves were born in 2020. Meaning that the eldest cows from him are second calvers.
Diving in the data further, there are around 8,740 bulls on the EBI proof list; about 1,564 of these are still active.
According to ICBF data, 8,559 bulls rank higher than Kilfeacle Pivotal in relation to TB resistance.
The table below shows that out of the roughly 1,564 bulls still active on the list, Pivotal finds himself to be the 25th bull for the lowest resistance to TB.
To have accurate health information in the EBI, data is required, so the likelihood is that more Pivotal progeny may be poorly ranked for TB resistance in the future.
On the active bull list there are 30 Pivotal sons and grandsons in the top 100, with more bulls broadly related to him on closer inpsection.