Farmers are being warned that their dairy cows are growing too much in stature, a trend which is hoped will be stopped to ensure efficiency.
For years now dairy cows have been growing in stature, but experts are saying cows need to stop 'getting bigger and bigger'.
AHDB Dairy explains that a maintenance value had been added into the most commonly used breeding indices to try and stop UK dairy cattle getting any bigger.
In time the value should see fewer very large cows being bred.
While breeding indexes such as the Profitable Lifetime Index (£PLI) and the Spring Calving Index (£SCI) have always included key traits such as fertility, longevity and production, maintenance has been a more recent addition.
Using the genetics of the terminal sire it estimates the mature weight of the daughter compared to the average heifer which means farmers should be looking for a negative result.
'We need them to stop getting bigger'
AHDB Dairy Technical Manager Andy Dodd said: “We don’t necessarily need cow size to reduce, we just need them to stop getting bigger and bigger.
“The maintenance value will estimate how far above or below the average weight the daughter of the sire is likely to be, and to keep size at a reasonable levels we want farmers to select those which are likely to be lighter than average.
“Maintenance is really about efficiency. Historically farmers bred bigger animals to produce more milk, but we know smaller animals can produce just as much, so often bigger cows simply cost more to feed.
“There is also a concern on many farms about cows outgrowing the cubicles in both sheds and parlours and incurring extra costs there.”
Herd and production requirements
However, Mr Dodd also stressed that understanding herd and production requirements is key to getting selection right.
He said: “For dairy farmers working on contract they will generally need to select for volume, fat and protein, however the criteria processors are looking for can often vary hugely so producers really need to tailor their cattle breeding plans to their system.
“Others producers may be looking to improve the health of their herd and so should be prioritising things like fertility, lifespan and somatic cell counts.”
