At this time of year, the annual respite following calving gives autumn block herds valuable time to reflect on what went well, where improvements can be made, and to begin to think about breeding for next season.
Good breeding 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 decisions.
Marco Winters, AHDB head of animal genetics, says: “Much of a herd’s genetic gain can be put down to bull choice, but this can be enhanced by breeding from the right cows and heifers.”
He explains that on-farm data and records can help, but a more accurate approach would be to use your herd genetic report, which illustrates your herd’s genetic strengths and weaknesses, highlighting areas to address with the next team of bulls you choose to use on your herd.
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? Mr Winters says 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, targeting production of about 7,500kg/year.
“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,” says Mr Winters.
“£ACI is recommended as an initial ranking tool for dairy sires. Our recommendation is to use this figure to filter out the bottom 50 per cent of available bulls, leaving the better genetic bulls,” he says.
“After that, producers should drill down and look at the index’s individual components to improve the traits most important in their own herds.”
Top tips to prepare for semen purchase
■ Assess your herd’s strengths and weaknesses Using AHDB’s herd genetic report or physical on-farm data
■ Set a breeding goal Where do you want your herd’s performance to be in five to10 years’ time?
■ Set priorities Set three key achievable priorities that will have visible results and deliver a positive return
■ Where does your herd need to develop and what are your aspirations? For example, reduce incidences of lameness, as this uses the most medicine, or improve your herd’s fertility so you can start to use sexed semen
■ How much semen and what type to purchase? Decide how much conventional, sexed semen and beef semen needs to be purchased
IN THE FIELD MATT FORD, EAST SUSSEX
MATT Ford runs an autumn calving herd and explains that when selecting bulls, he starts at the top of the £ACI list and works his way down, making sure the bulls are meeting the levels of fertility, fat and protein that he wants.
He says: “We have gradually moved from two 12-week blocks, spring and autumn, to a fully autumn calving herd and tightened the block up to nine to 10 weeks.
“We have done that by bringing in more heifers, selecting the right genetics and being strict on what cows stay in the herd.”
Mr Ford uses the herd genetic report to check how his herd is performing at a national level and spot any areas of weakness.
He says: “We have been pushing more for fertility rather than milk, so we are only on about the 50th percentile in yield, whereas our fertility is in the top 15 per cent. Our milk solids, percentage of fat and protein have improved in the last couple of years.”
Previously Mr Ford had been selecting by profitable lifetime index, but he says the £ACI is more suited to his system.
He says: “Overall with the herd genetic report, it is encouraging to see we are making good progress and our youngstock are now in the top 1 per cent nationally.”