Unreliable cows that don’t get in calf easily each season create stress and rob farmers of profit. All farmers want cows that produce well, get back in calf, and remain in the herd as long as possible. That’s becoming more achievable on-farm, thanks to recent research findings from the Pillars of a New Dairy System programme*.
Pillars has uncovered the significance of the Fertility BV in contributing to reproductive performance. Our measure of reproductive performance, the 6-week in-calf rate, is driven by cows being submitted and conceiving in the first three weeks of mating. Trial work demonstrated that animals with higher Fertility BVs started cycling sooner and had higher submission rates, giving them more opportunity to get in calf.
What does this mean for your herd?
The trial compared cows with extremes of high (+5) and low (-5) Fertility BV, which you won’t see on a typical farm. The trial isolated the BV to understand how it impacts a cow’s reproductive performance. The current average Fertility BV for a New Zealand cow is 0.5; we’d consider any herd with an average Fertility BV below this to be low.
To find out your herd’s Fertility BV, request a ‘Herd BV Averages’ report from your herd improvement company. Compare the figure for your mixed-age cows with your younger animals. We want to see the Fertility BV trending upwards in the younger animals, indicating progress.
If your herd’s Fertility BV is below average and/or is lower in younger animals, you may want to emphasise fertility in your breeding goals.
Also consider your herd’s current reproductive performance. The New Zealand average for 6-week in-calf rate sits around 67 percent, compared with the industry target of 78 percent. Herds with lower performance will see more impact from improving a low herd Fertility BV than a herd with above average performance.
Choosing bull teams
When selecting your mating programme, take all your breeding goals into account. Using an automated team of bulls from your breeding company can be sufficient, but it pays to compare your herd’s BVs with the proposed bull teams’ BVs.
The best way to control the genetic improvement of your herd is by nominating bulls. Select bulls with as high a Fertility BV as possible, without compromising too much on your other breeding goals.
* Funded by dairy farmers through the milksolids levy and by the Ministry of Business, Innovation and Employment (MBIE). For more information dairynz.co.nz/pillars
- Genetics is only one of eight key management areas of reproduction.
- Know your herd’s current Fertility BV status before planning your breeding programme.
- Use your support network to assess your herd and plan for improvement.
This article was originally published in Inside Dairy April 2020