SUPPLEMENTAL DIETARY BIOTIN FOR PREVENTION OF LESIONS ASSOCIATED WITHASEPTIC SUBCLINICAL LAMINITIS (PODODERMATITIS ASEPTICA DIFFUSA) IN PRIMIPAROUS COWS

Objective-To evaluate, in primiparous cows, the effect of dietary biot in supplementation on severity of lesions of aseptic subclinical lamin itis. Animals-100 primiparous cows in a 800-cow commercial dairy herd. Procedure-Cows were assigned after calving to a biotin-supplemented ( 20 mg/head/d) or control group on an alternating basis. Digits 3 and 4 of the left forelimb and right hind limb were examined at a mean of 2 5, 108, and 293 days after parturition. Toe length, hoof angle, and he el depth were measured, and hooves were examined for solear hemorrhage , yellow solear discoloration, separation of the white line, and heel erosion. Serum and milk biotin concentrations were also measured. Resu lts-Serum biotin concentrations were significantly higher for suppleme nted than for control cows. During the second examination, prevalence of separation of the white line of digits 3 and 4 of the hind limb and digit 4 of the forelimb was lower for supplemented than for control c ows. Mean decrease in heel depth between the first and third examinati ons was approximately twice as great for digit 4 of the forelimb and 4 times as great for digit 3 of the forelimb in supplemented, versus co ntrol, cows. Other differences were nor found. Conclusions and Clinica l Relevance-Results suggest that supplemental dietary biotin may have a beneficial effect on hoof health in intensively managed primiparous dairy cows.