Damaged hocks are a possible cause of lameness
FAR more attention needs to be paid to hock damage, said Jon Huxley of Nottingham University, as many UK cows are likely to be ‘hock lame and not foot lame’.
He said it was wrong to assume hock damage was a consequence of lameness and not the cause of it, as it was not necessarily the case only lame cows damaged their hocks (by moving awkwardly in and out of cubicles and lying uncomfortably).
Some cows could be lame because of damage to their hocks, with no issue affecting their actual feet.
Dr Huxley stressed this was currently only a hypothesis, the result of his interpretation of research at the university, but was certainly something requiring a more serious look at.
He said it was also wrong to assume hair loss led onto ulceration, followed by swelling, he said, as the same study found distinct risk factors for all three hock problems, suggested they were not closely related to each other.
The only factor causing both hair loss and ulceration was when cows were housed on sawdust over mats/mattresses. All the other factors caused hair loss or ulceration or swelling, not all three.
Although hair loss and ulceration were not found to be linked to each other, they were both linked to mobility score, meaning cows with hair loss or ulceration were more likely to have impaired locomotion. However, no link was found between swelling and mobility.
The hock damage study
The study comprised 3,691 randomly selected cows across 77 herds scored out of four for hair loss, ulceration (skin breakage) and swelling. Score 0 indicated no damage, through to 4 being severe damage.
- 7,382 lesions were found
- 38 per cent of hocks had moderate or severe hair loss
- Hair loss was mostly limited to 10 sq cm, but occasional cases of 100 sq cm were recorded
- 17 per cent of cows had some ulceration
- Ulcers were mostly 2.5 sq cm, but occasional ones were 40 sq cm