Effekt av biotintillförsel på klövhälsan hos mjölkkor i lösdrift : ett kontrollerat fältförsök på tre gårdar
Abstract: The aim of the present degree project was to investigate the effects of biotin supplementation on hoof health in dairy cows. The experiment was performed as a controlled cohort study in three commercial farms in western Sweden from January 2002 to October 2002. The cows were all housed in cubicle systems with transponder concentrate feeding systems. Within each farm the cows were allocated to either biotin or control treatment. The biotin groups received 20 mg of biotin per cow and day, starting 14 days before expected calving. After the third month of lactation the amount of biotin fed was decreased to 10 mg of biotin per cow and day. No biotin was fed during the dry period. Control cows did not receive any supplementary biotin. During the experiment the cows were trimmed once before calving and once or twice after calving by a professional foot trimmer. Claw lesions were recorded, and toe length, diagonal length and upper claw angle were measured before and after trimming. Effects of biotin on hoof disorders (heel horn erosion, sole haemorrhage, white line haemorrhage, sole ulcer, dermatitis and white line fissure) at the end of the study were analysed using multi variable logistic regression, controlling for effects of herd, days in milk and parity. Net growth between different seasons (trimming 1-2; 2-3; 1-3) was calculated from the claw measurements. The effects of biotin were analysed using multivariable linear regression controlling for effects of herd, days in milk and parity. Biotin supplementation was not associated with claw health or growth rate. There are, however, literature reporting positive effects of biotin supplementation on hoof health. By extending the present experiment over a full housing period, as well as by increasing the amount of biotin fed, chances to see effects of biotin might be bigger.
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