Lameness is an animal welfare issue and a major economic loss on many dairy farms. Common causes of lameness include sole hemorrhages, white line hemorrhages and sole ulcers, which can be categorized as claw horn lesions. These claw horn lesions can develop around calving and early lactation, and become noticeable around peak or mid-lactation. The current hypothesis is that claw horn lesions are a result of a bruise within the claw horn capsule. Physiological changes around calving and early lactation, such as weakening of connective tissue of the hoof suspensory apparatus and the decrease in thickness of the digital cushion, increase the risk of bruising, especially in poor housing conditions.
In the September issue of the Journal of Dairy Science , University of British Columbia researchers showed that cow behavior during the transition period may contribute to the development of claw horn lesions by exacerbating environmental and physiological risk factors for lameness.
Cows diagnosed with claw horn lesions seven to 15 weeks after calving spent more time standing than cows without lesions during the two weeks before calving (~two hours more) and the 24 hours after calving (~four hours more).
Interestingly, the cows that developed claw horn lesions spent ~1.5 hours more per day during the last two weeks before calving perching with front feet in a stall.
In addition, cows diagnosed with claw horn lesions in mid-lactation ate at a faster rate and had more frequent but smaller meals during the two weeks before calving compared with cows not diagnosed with claw horn lesions.
Surprisingly, during the first 24 hours after calving, cows that eventually developed lesions consumed more feed in more frequent meals. Also, the feeding rate tended to be faster. Additional work is needed to understand how feed consumption after calving affects the development of claw horn lesions.
The behavior predictors of claw horn lesions described above provide additional support for proper facility design and implementation of good management practices during the transition period. Facilities and management practices aimed at minimizing excessive standing and perching by providing comfortable lying surfaces may be beneficial for reducing the occurrence of claw horn lesions in the weeks after calving. PD
âÂÂExcerpts from From Miner Institute Farm Report, September 2010
Heather Dann
Research Scientist
Miner Institute
dann@whminer.com
