Breeding decisions for autumn calvers

At this time of year, the annual respite following calving gives autumn block herds valuable time to reflect - what went well, where improvements can be made and begin to think about breeding for next season.

Good choices made now can deliver cumulative benefits for years to come, but while bull selection plays a vital role, producers should consider how their herd’s make-up affects the impact of any those decisions.

“Much of a herd’s genetic gain can be put down to bull choice,” says Marco Winters, AHDB head of animal genetics, “but this can be enhanced by breeding with the right cows and heifers.”

On-farm data and records can help, but a more accurate approach would be to use a Herd Genetic Report, which illustrates strengths and weaknesses as well as highlighting areas to address.

The report also allows farmers to compare their herd performance nationally and can help when setting targets.

Once you have assessed your herd, how should you choose bulls? Producers breeding replacements for autumn calving herds tend to require more milk volume and weight of fat and protein as well as prioritising fertility.

Introduced last year, the Autumn Calving Index (£ACI) is designed for UK farmers who autumn calve in a block of 12 weeks or less and have a higher requirement for winter feeding and targeting production of around 7,500 kgs/yr.

“The index was developed in response to demand from farmers and the industry and reflects the slight increase across the UK in autumn block calving,” said Marco.

“£ACI is recommended as an initial ranking tool for dairy sires,” he says. “After that, producers should ideally drill down and look at the index’s individual components to improve the traits most important in their own herds.”

Now you’re ready to buy semen and here the adage ‘prior preparation prevents poor performance’ comes into its own and ensures you get the most from your decisions.

Tops tips to prepare for semen purchase

1. Assess your herd’s strengths and weaknesses - using AHDB’s Herd Genetic Report or physical on farm data 

2. Set a breeding goal – where to you want your herd’s performance to be in 5-10 years’ time?

3. Set priorities - set three key achievable priorities that will have visible results and deliver a positive return.

4. Where does your herd need to develop and what your aspirations?

• E.g. reduce incidences of lameness as this uses the most medicine
• Or improve your herd's fertility so you can start to use sexed semen

5. How much semen and of what type to purchase? Decide how much conventional, sexed semen and beef semen needs to be purchased.

A farmer’s perspective - Matt Ford, autumn calver in East Sussex

When I select bulls, I start at the top of the £ACI list and work my way down, and make sure they’re meeting the levels of fertility, fat and protein that I want.  

We’ve gradually moved from two 12-week blocks, spring and autumn, to a fully autumn calving herd and tightened the block up to nine to ten weeks. 

We’ve done that by bringing in more Heifers, selecting the right genetics and being strict on what cows stay in the herd. 

We use the herd genetic report to check how we’re doing at a national level and to see any gaps. We’ve been pushing more for fertility rather than milk, so we’re only about 50^th percentile in yield, whereas our fertility is in the top 15%. Our milk solids, percentage of fat and protein have improved in the last couple of years. 

Previously I’d been selecting by £PLI but now with the introduction of £ACI I feel that it much better suits our system as the traits are better matched with autumn calving. Overall with the herd genetic report, it’s encouraging to see we’re making good progress and our youngstock are now in the top 1% nationally.

ADHB are running a series of Breeding Blocks workshops through October and November where farmers can learn how to evaluate their herd status and select the right sires to meet their breeding goals.