title: Hock angles of dairy heifers in two management systems.
abstract: Hock angles were measured in 30 Holstein heifers in one herd housed either indoors on concrete slats or out of doors on dirt. Two examinations were made, i.e. at 12-13 and 24-26 months of age. Overall, the heifers had straight limbs; the mean value of the hock angle was 167.3 degrees +/- 0.7 (SEM) (range 154.3-177.4 degrees). Hock angles decreased with age in each group, but the difference between the first and second examinations was significant only for outdoor-housed heifers (P < 0.05). At the first examination, mean hock angles were not significantly different between the two groups (169.5 degrees +/- 1.6 vs 168.1 degrees +/- 1.6), but at the second examination indoor-housed heifers had significantly greater mean hock angles than heifers housed out of doors (167.4 degrees +/- 1.0 vs 164.2 degrees 1.3) (P < 0.05). Heifers housed indoors on concrete slats appeared to retain their straight-angled hocks.
authors.affiliation: Department of Veterinary Anesthesiology, Radiology and Surgery, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
authors.forename: J J
authors.initials: JJ
authors.lastname: Vermunt
authors.forename: P R
authors.initials: PR
authors.lastname: Greenough
mesh_terms: D000367:Age Factors; D000818:Animals; D002417:Cattle; D005260:Female; D006614:Hindlimb / Q000033:anatomy & histology*; D006799:Housing, Animal