Lameness breeding trait due for release in New Year

Published 1 December 17

Fern PearstonBy Fern Pearston, AHDB Dairy Animal Genetics Manager

Lame cows produce between 300 and 600 fewer litres of milk per lactation, take 20 to 40 days longer to get back in calf, and are more likely to be culled. This makes lameness one of the most costly challenges faced by British dairy farmers today as well as a major welfare concern of the industry. 

That’s why at AHDB Dairy we have been developing a lameness breeding index, so we can reduce the incidence of lameness, reducing losses to the herd and to production. There have been indirect attempts to reduce lameness through breeding for type, for example selecting for improved locomotion could produce offspring less prone to lameness, but we know that the best way to change a trait is to select directly for it.

To better understand the genetics behind lameness we have combined type data, including Digital Dermatitis records, from Holstein UK with lameness recording supplied by the milk recording companies NMR and CIS. Earlier this year we ran a preliminary evaluation using this data which produced lameness breeding values for 47,000 sires. This opened the door to producing a heritable trait the industry can use to breed for reduced lameness. 

This work has found the heritability of lameness to be 9% which admittedly looks low compared to traits such as production which is approximately 50% heritable, but the new trait can still make a significant difference to our lameness levels, especially when paired with best practice management on farm.

Back in 1999 we produced a breeding index for somatic cell count (SCC) which has a similarly low heritability and through it we have seen the trend for rising somatic cell counts dropping dramatically both genetically and on farm. The graph below shows both the genetic breeding value and recorded level of SCC of the national herd peaking between 2007 and 2008.  Following this peak, the somatic cell count in both has declined significantly, with slight fluctuations due to management practices.

So, my advice is not to judge a breeding index by the trait’s heritability, as this new trait has the potential to make a real change to the prevalence of lameness on farm.

Lameness, along with new breeding values for calf survival and carcass traits, will be released next year, and we are investigating how best to include this into the national breeding indexes; the Profitable Lifetime Index (£PLI) and Spring Calving Index (£SCI).

After the trait launches more information will be available on our website, where of course there are lots of other helpful tools to manage lameness including the AHDB Dairy Healthy Feet Programme which has successfully helped farmers across the UK reduce lameness incidences in their herd.

Graph which shows reduction in somatic cell count (SCC) in national dairy herd 

Graph Which Shows Reduction In Somatic Cell Count (SCC) In National Dairy Herd