How dairy farmers can benefit from genetics

Farmers were asked which traits they were hoping to improve through genetic selection, offering the following four choices:

• Easy calving
• Productivity
• Improved health
• Other e.g. temperament

Promisingly, 40% of farmers were looking to improve herd health. Traits such as reduced lameness and mastitis are correlated with better fertility, so there is scope to improve overall herd performance through this selection.

Productivity, at 35%, was the second most common trait that farmers hope to achieve. As milk production determines farm turnover this is perhaps unsurprising, but care needs to be taken, as geneticists have found that higher milk yield can negatively correlate with fertility¹.

“Fertility in high yielding cattle can be depressed for a wide variety of reasons, including being in a negative energy balance, suppressed immune function and expressing heat behaviours for a shorter time period. It is important to optimise cows’ management through adequate nutrition, minimised stress and robust disease control and preventative health measures, particularly during the transition period,” advises Dr Baldry.

Genetics can predict conformation, susceptibility to mastitis, lameness, bovine tuberculosis, and fertility performance. Farmers were asked to rate how important genetics is to herd health on a scale from ‘very important’ to ‘not at all important’.

Unsurprisingly, 61% answered “very important”, with the majority of farmers recognising the potential of genetics to set up their herds for a healthy future. Genetics has a particular impact on fertility, both by selecting for a positive fertility index and through the correlation between other health traits and better fertility.

This has fed through into national herd performance; Kingshay’s Dairy Reports highlight that the cost of infertility has fallen from 2.07ppl last year to 1.87ppl (based on their model farm size and yield). Along with other improvements, the 200- day not in- calf rate fell from 16% to 13%.

Artificial insemination provides the opportunity to access the best genetics in the world, and to choose bulls that have been proven or genomically tested for the traits desirable on your farm. The survey asked dairy farmers what percentage of their breeding is done by AI;

• 0-24%
• 25-49%
• 50-74%
• 75-100%

85% of farmers said that over half of their breeding was done by AI, suggesting that most dairy businesses recognise the advantages that can be gained.  

“If your farm has a stock bull or hires in bulls for breeding purposes, biosecurity is of the upmost importance,” says Dr Baldry.

“If buying or hiring a bull in, it is crucial to understand the disease and vaccination status of the herd you are buying in from. Any incoming stock must be aligned with your own farm’s vaccination and disease monitoring protocols. Yearly breeding soundness checks are a good way of ensuring the bull has a full MOT and is fully functioning, producing viable sperm. If only using a bull, care must be taken to avoiding any inbreeding,” she adds.

For this question followers were given a binary choice of ‘yes’ or ‘no’.

Just 39% of respondents had used genetics to counter a specific health issue, meaning that nearly two thirds of farmers had not maximised the potential of genetic selection to target known problems in the herd.

Disease? Not On My Farm!’ ambassador, Jessica Langton has first-hand experience of effective disease control helping to improving cow fertility:

“Historically we had low fertility performance, with a 10% empty rate and 25% of cows holding to the first service. After a bulk milk tank test showed IBR in our herd, we followed vet advice and introduced a vaccination programme.

“Since then, herd health has improved. Our empty rate is currently nearly zero and 55% of cows hold to the first service with sexed semen, and 75% do across the herd,” says Jess. 

Fertility remains one of the greatest areas where further savings can be made. By combining high fertility genetic selection with better transition cow management, vaccination against diseases and routine veterinary visits, farmers can take steps to improve it.

At a milk price of 48ppl Kingshay anticipate that every day over a 385-day calving interval will cost £6; taking into account a typical herd size and that the average calving interval is 393 days there is scope for savings in many herds.