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要 約
肉用牛の輸送ストレスに及ぼす削蹄の効果について検討した．黒毛和種肥育牛41頭を削蹄群（27頭）と無削蹄群（14頭）に分けた．削蹄群は6カ月ごとに削蹄され，出荷3カ月前に最後の削蹄を行った一方で，無削蹄群は肥育期間中にまったく削蹄されなかった．出荷に伴うトラック輸送（距離57.8km，4時間）の前後で，体重測定と血液および血液化学検査を行った．クレアチンホスホキナーゼ（CK）活性およびコルチゾール値は輸送後に増加したが，いずれも，削蹄群の値が無削蹄群に比べて低い値を示した．CK活性の変化は，定期的な削蹄が牛蹄の負重機能に安定性を与え，肥育後期の肉牛の筋肉にかかる侵襲を抑制する効果があることを示唆するものであった．また血清コルチゾール値の変化とあわせて，肥育牛における定期的な削蹄は，出荷時の輸送ストレスに対する抵抗性を高めることが明らかとなった．
―キーワード：肉用牛，削蹄，輸送．
--------------------日獣会誌 54，837〜840（2001）
Effects of Hoof Trimming on Hematological and Biochemical Variables during Transport-induced
Stress in Japanese Black Cattle
Kazuhiro MISUMI＊†, Takeshi SHINSATO, Osamu AOKI, Kentaroh SETOYAMA, Naoki
MIURA, Kohichi YANAGITA and Hiroshi SAKAMOTO
＊Faculty of Agriculture, Kagoshima University, 1-21-24 Koorimoto, Kagoshima 890-0065, Japan
SUMMARY
The purpose of this study is to determine effects of hoof trimming on transport-induced
stress in beef cattle. Forty-one Japanese black steers were randomly divided into 2 groups: trimmed group
(n=27) and untrimmed group (n=14). In the trimmed group, hoof trimming was repeated every 6 months, with
the final trimming performed 3 months before shipment. The untrimmed group was not trimmed at all until
shipment time. Before and after truck transportation to the shipping destination (57.8 km, 4 hours),
the cattle were weighed, and their blood was sampled for hematological and biochemical analysis. The
indices of transport-induced stress were creatine phosphokinase (CK) and cortisol. In both groups, CK
and cortisol increased after transportation. Increase in the parameters was lower in the trimmed group
than in the untrimmed group. Lower CK activity in the trimmed group suggests that the physical demand
for posture support during transport in the vehicle was more restricted in the trimmed group. Plasma
cortisol increased less in the trimmed group than in the untrimmed group. This could mean that periodical
trimming effectively inhibits transport-induced stress in beef cattle.
―Key words : beef cattle, hoof trimming, transportation.
| † Correspondence to : |
Kazuhiro MISUMI (Faculty of Agriculture, Kagoshima University)
1-21-24 Koorimoto, Kagoshima 890-0065, Japan
TEL・FAX 099-285-8730
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-------------------- J. Jpn. Vet. Med. Assoc., 54, 837〜840 (2001) |
