UK - Managing body condition score to peak yield could be key in addressing lameness, say researchers who have studied how cows mobilise fat from a protective foot pad in the hoof.
Three University of Nottingham trials have shown the “direction of causality” in claw horn lesions, the Total Dairy conference heard yesterday.
This is the conundrum over whether, as a general rule, thin cows become lame, or lame cows become thin.
The findings link high yielding cows to be “predisposed” to lameness issues as they lose more Body Condition Score (BCS).
Central to understanding the issue is the role of digital cushion in protecting the hoof from impact.
Three cylindrical bodies of fat placed in parallel at the bottom of the hoof are responsible for “transferring and displacing” force during the initial foot strike action of walking when the load is maximal. (See image)
This is according to Professor Jon Huxley, Nottingham School of Veterinary Medicine and Science, who emphasised the link between high milk production, loss of BCS and lameness.
“Lameness is a disease of high production, this has been reproduced in a number of studies around the world,” he said. “When BCS drops, cows can mobilise fat from the foot pad, slimming down the digital cushion.”
He said this has come out of the last five to ten years of research and that, although more work was required, he didn’t think it was too early to address claw horn lesions by looking at BCS and peak yield.
He said it raises some “interesting questions” about how nutrient management might alter the structure and function of the foot pad.
“These studies are all basically saying it appears that the loss of body condition precedes the lameness event," he said. "We now have some direction to the process of causality.
“Our work suggests that managing body condition score to peak yield could be key in controlling white line disease and soul lesions.”
However, he said having fatter cows doesn’t appear to offer any “wriggle room”.
“Cows with high BCS are still at risk. It will probably be about minimising the proportion of cows that lose a lot of weight to peak yield.”
At this point, it looks unlikely current BCS recommendations having to alter much, he told the seminar.
Another issue to address is whether cows mobilise fat differently and what happens to the foot when the structure becomes damaged.
He made a distinction between when the loss occurs and how the loss occurs.
“We can’t say yet which is more important,” he added. “My best guess is its about rate of extended loss and absolute nadir.”
Image courtesy of the University of Nottingham