Inbreeding – Is the Data Accurate?

When making breeding decisions, inbreeding has become a major consideration for dairy farmers. The graph below from AHDB Dairy, clearly shows the rising trend of inbreeding, with the recommendation to keep an animals inbreeding percent below 6.25%.

Farms now have a range of mating programmes available to help with selecting bulls, however, these all differ slightly.

Commonly, farmers will use a breeding companies mating programme, these will recommend bulls to fit a given criteria on farm and take account of resulting inbreeding. These programmes work well but often only use a limited number of generations of males and females to calculate inbreeding percentiles, potentially missing important information. It is also key to remember; the companies use these mating programmes as a sales tool to sell their bulls.

Alternatively, there are two main independent options if farmers have some understanding and confidence when selecting bulls:

Holstein UK (HUK) has its own mating programme that has been available for many years. This allows farmers to select bulls to meet their specific breeding criteria, however, caution needs to be taken as farmers have been reporting issues with the results. In some cases, the predicted inbreeding results appear to be incorrect and having reviewed the data on one clients farm, on average, the inbreeding figure was 2.6% below that reported for a group of 16 animals on a different programme. If the client had accepted the initial figures from the HUK site he would have mated the 16 animals to the 3 bulls he had selected, however, having analysed the data through the AHDB inbreeding checker, only two of the animals would remain below the guide of 6.25% when mated with the selected bulls, some animals varied by nearly 10%. So back to the drawing board!

Another alternative is AHDB’s inbreeding checker which is available to milk recording herds in the UK by signing up for a Herd Genetic Report. This tool is again independent and works alongside the genetic evaluation work that AHDB carry out to allow you to select bulls that meet your breeding requirements along with the inbreeding result for selected matings.

UK farmers have worked hard to select animals that will slow the speed of inbreeding within their herd, as can be seen below, but, through no fault of their own, if incorrect data is presented to them, the rate of inbreeding will rapidly increase again. All systems calculate in a slightly different way, but it is important to sense check any results to ensure errors are minimised.

For independent advice on analysing your herd inbreeding levels and help creating a breeding policy specific to your farm, contact Andy at or contact your local FCG Office.

Posted in Business Management, Chippenham, Dairy & Forage.