Inbreeding in all breeds of dairy cattle has become a growing problem over the years which in turn has had a negative effect on herd health and profitability.

According to figures from AHDB, all the main dairy breeds have increased their levels of inbreeding, with pedigree Holstein females born in 2017 containing the highest amount at an average of around 5%. Average figures are now at more of an acceptable level.

This enables natural processes to remove harmful recessive genes over generations, ensuring favourable genetics and healthy animals.

SRUC research has shown that if inbreeding is below 5% it has a negligible effect on production and management traits evaluated by AHDB Dairy.

However, for every 1% increase in inbreeding above 5% we could expect approximately 16kg milk to be lost per lactation in the resulting progeny, as an example.

Looking at the Profitable Lifetime Index (£PLI), as a measure of overall genetic improvement, the analysis found that for each 1% increase in inbreeding above 5%, 10 points £PLI equivalent would be lost in the resulting progeny. That is to say, the profitability of the progeny based on her genetic potential would decrease by £10 in her lifetime due to inbreeding depression.

To ensure inbreeding levels remain acceptable, AHDB has developed a number of tools to help farmers monitor and manage inbreeding, together with achieving valuable genetic improvements.

On-line Herd Genetic Reports allow farmers to monitor the genetic qualities of their herd and also includes data on inbreeding, while the Inbreeding Checker helps manage short-term inbreeding in the next generation, by allowing the farmer to check how related all available bulls are to the herd. The key of course is to use a variety of bloodlines to manage long-term inbreeding.

UK genomic inbreeding figures will be available for genotyped animals from AHDB Dairy in the coming year.

This will give a more accurate estimate of how inbred an animal is, and once UK genomic inbreeding figures are available to the industry, these will be incorporated into the AHDB Inbreeding Checker to manage future matings. This, along with the other proposed updates, aims to better control the rate of change in inbreeding.

For example to control long term inbreeding, an additional step will be added to the tool once potential sires have been selected to use on the females. The tool will indicate if these bulls are closely related to each other, encouraging the user to consider a variety of bloodlines in their choice of mating sires.

If you would like to sign up for a Herd Genetic Report please contact with your milk recording number, trading name and address. Please note you must be fully milk recording with NMR, CIS, Dale Farm or QMS to qualify for a Herd Genetic Report.