Cow reproductive efficiency falling

There is clear evidence that the reproductive efficiency of Irish beef cow herds is in decline, Teagasc experts told Beef 2014 at Grange, Co Meath.

For example, fewer than 0.8 calves are being born per cow per year, and fewer than 25% of cows produce a calf within a year. The calving interval is also increasing, and now averages about 400 days.

Fewer than 10% of heifers calve for the first time at 24 months of age, with an average age at first calving of 32.5 months.

Undoubtedly, while some of this inefficiency can be attributable to poor management practices, data from the Irish Cattle Breeding Federation shows there is a significant genetic component in the declining reproductive efficiency of the national beef cow herd.

Teagasc has begun studies aimed at both understanding and improving reproductive efficiency and increasing the use of AI in beef cow herds.

Fewer than 20 calves are born to AI sires per 100 beef cows calved.

Another factor is that 5% of bulls can be infertile, while up to 25% experience sub-fertility.

It is essential that vigilance for bull fertility and mating performance is maintained throughout the breeding season.

Teagasc is examining the effects of genetics and nutrition on bull fertility, and the potential for sexed semen use on beef cows.