According to ICBF, the average calving interval on Irish farms is 402 days; the ideal target is 365 days.
The median calving date is Mar 10; the optimum target for most farmers is Feb 20.
The average six-week calving rate is 52%; the best performing Irish farmers have 60%; and the ideal target is 70%.
Pregnancy rates to first service are 52%; the target is 68%. Submission rate is only 60%; the ideal target is 90%, but this is impossible for most herds with a scattered calving pattern.
Calves per cow per year are 0.85; the target is 0.95.
As we can see from these figures, there is a lot of room for improvements. These improvements are more important than ever now, because an early, compact calving pattern will be required to obtain the best price for milk.
It is not easy to achieve the above targets, as we know from the performance on so-called model farms with “expert” management. However, we know our best farmers are getting closer to the targets, but it is difficult where existing calving patterns are very scattered. It can only be achieved by batch calving heifers at the start of the calving season and adhering to best breeding practices.
Despite being somewhat off target, the breeding performance of the best farmers in Ireland is as good, if not better, than those in New Zealand and Australia. Some of the New Zealand breeding achievements are enabled by some unethical practices which are now fading out.
Over half of New Zealand’s and Australia’s cows have a strong Jersey and crossbred influence, and the Jersey genes are increasing every year.
Yet, according to Australian fertility expert Jock McMacmillan, speaking at the recent fertility conference organised by Teagasc, fertility is declining in these countries. From 1997 to 2009, all the important fertility parameters have deteriorated very significantly, by about 1% per year. For example, conception rates to first service have declined from 49% in 1997 to 38% in 2010/2011.
The general consensus in these countries is that genetics for fertility are more than any particular breeds. They also find that higher milk yields per cow do not adversely affect fertility.
In Ireland, the ICBF has found a very close relationship between herd fertility index and herd fertility performance.
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