蹄底潰瘍，蹄球びらんおよび趾間フレグモーネの乳牛における血中ビオチン濃度

NOSAI宮城県南家畜診療センター（〒989-0731　白石市福岡深谷字地蔵堂25）

（1999年6月3日受付・1999年8月30日受理）

要　　　　　約

蹄病牛における血中ビオチン濃度を明らかにする目的で，蹄底潰瘍，蹄球びらんおよび趾間フレグモーネの乳牛において血清中のビオチン濃度とビオチニダーゼ活性を検討した．その結果，血清総ビオチン濃度は正常牛に比較して各蹄病牛で低値を示し，特に蹄底潰瘍牛と蹄球びらん牛では有意な低値を示した（それぞれP＜0.05，P＜0.01）．しかし，血清遊離ビオチン濃度は各蹄病牛と正常牛との間で差異がみられなかった．血清ビオチニダーゼ活性は各蹄病牛と正常牛との間で差異がみられなかったが，ビオチニダーゼ活性と総および遊離ビオチン濃度との間に正の相関が認められた．これらのことから，蹄底潰瘍牛と蹄球びらん牛では，正常牛に比べ給与飼料からのビオチン摂取やルーメン内におけるビオチン産生は低下していることが示唆された． ―キーワード：ビオチン，ビオチニダーゼ，乳牛，蹄球びらん，蹄底潰瘍． --------------------日獣会誌　53，136〜139（2000） Serum Biotin Concentrations in Dairy Cows with Sole Ulcer, Heel Erosion and Foot Rot Shigeru SATO，Toshihiro ICHIJO, Toshiyuki SUZUKI and Hideya ONO Ken-nan Veterinary Clinic Center, Miyagi Prefectural Federated Agricultural Mutual Aid Association, 25 Jizodo, Fukuoka-Fukaya, Shiroishi 989-0731，Japan SUMMARY 　Serum concentrations of total and free biotin and biotinidase activity were investigated in diary cows with, such hoof disorders as sole ulcer, heel erosion and foot rot (interdigital necrobacillosis). The agar-plate method of biotin bioassay using Lactobacillus plantarum ATCC 8014 and the colorimetric biotinidase-assay method were employed. Total-biotin serum concentrations were significantly lower in cows with sole ulcer (P＜0.05) and heel erosion (P＜0.01) than in normal cows. Free-biotin serum concentrations in cows with hoof disorders were similar to those in normal cows. No significant difference was observed in serum biotinidase activity between cows with hoof disorders and normal cows. Positive correlations were observed, however, between biotinidase activity and concentrations of total and of free biotin. It may be that biotin ingestion from feed and biotin synthesis by rumen bacteria may decrease below levels in normal cows in dairy cows with, such hoof disorders as sole ulcer and heel erosion. ―Key words : biotin, biotinidase, dairy cows, heel erosion, sole ulcer. --------------------J. Jpn. Vet. Med. Assoc., 53, 136〜139 (2000)