| Popis: |
Biotin was supplemented at three levels (0, 10 and 20 mg/steer.day) to 108 F1 Wagyu/Black Angus steers of known genotype, which were fed a wheat-based ration, to evaluate the effect on hoof growth, wear and integrity within feedlot pens. One hundred and eight steers of known sire lines were assigned to three biotin treatments (0, 10 and 20 mg/steer.day) with each treatment replicated four times using an unfasted liveweight of 410.5kg (s.e. ± 2.27, s.d. ± 24.41). A subset of 36 steers was randomly selected for monitoring of hoof growth on seven occasions, over a period of 301 days. Front hooves from selected steers within turn-off group were collected at the abattoir and investigated for hoof integrity through claw lesions, white line width and dry matter of both white line and hoof. Hoof growth rates over time remained relatively consistent. In contrast, hoof wear rates increased (P < 0.001) in association with rainfall and exceeded rates of hoof growth. Biotin supplementation did not affect (P > 0.05) hoof growth or wear. Examination of collected hooves revealed lesions present on both lateral and medial claws. Biotin supplementation had no effect (P > 0.05) on lesion number, white line width of the lateral and medial claws, or hoof and white line dry matter of the medial claw. In contrast, Grandsire had an effect on total hoof length at measurement periods 0, 167, 251 and 301 (P < 0.05), and also on white line width of both lateral (P = 0.015) and medial (P = 0.002) claws. Rainfall and related increase in pen moisture weakened hoof integrity by increasing hoof moisture content and hoof wear. Genotype appears to play a role in hoof integrity. |
