Calving difficulty as measured on a first-calving dairy heifer or on a mature milking cow are very different. Teasing out the differences between different groups so that they better reflect the calving difficulty of the sire used is the objective of proposed changes by the Irish Cattle Breeding Federation (ICBF).
ICBF geneticist Ross Evans said: “This will not have a big impact on the top EBI sires, but will allow more targeted breeding decisions, with the new proof run changes that are coming next week.”
No visibility
The problem for the geneticists working with the calving difficulty figures coming back from farmers was they had no visibility whether the calving difficulty figures were coming from heifers or cows.
On top of that, the first crop of calves from a particular sire might not be used on mature cows and might sway the calving difficulty figure more severely.
Changes are expected to take place over the coming weeks
So to better give farmers an indication of calving difficulty, there will now be a figure for calving difficulty for a dairy cow, a beef cow, a dairy heifer and beef heifer.
Ross gave an example of what will change. He said: “So in the old system, a range of 0.1% to 2.4% calving difficulty for a sire will now be broken down something like 2.7% for a dairy cow, 2% calving difficulty for a beef cow, 6.7% calving difficulty for a dairy heifer and 5% calving difficulty for a beef heifer.”
These calving data changes are going to take a good bit of time to change on the ICBF database, so changes are expected to take place over the coming weeks.
Over 200 farmers and industry personnel attended the dairy part of the ICBF breeding conference and awards ceremony in the Heritage Hotel in Killenard on Friday.