新生子馬における糞中のVFA，乳酸濃度の推移

佐藤　博^†　　　　黒澤　隆　　　　及川　伸

要　　　　　約 　子馬の腸内発酵の推移を調べるため，サラブレット種の新生子馬を用い，出生当日，翌日およびその後は1週ごとに7週齢までの新鮮糞を延べ113点採取し（実頭数は40），pH，揮発性脂肪酸（VFA）および乳酸を分析した．全例平均で糞のpHは7.52，乳酸は0.01％（新鮮物あたり;以下同様）であった．VFA総濃度の平均は0.26％で，酢酸が64％，プロピオン酸が21％，酪酸が15％であったが，大きな個体差があった．出生時のVFAは非常に低かったが，翌日から1週齢にかけて最高に達し，その後は低下傾向を示した．出生当日，翌日および1週齢には乳酸の著しく高い個体がみられたが（0.1％以上），下痢などとは関係なかった．糞のpHは1週齢で最低になり，2週齢以降には上昇する傾向を示した．子馬では出生後の吸（哺）乳直後から大腸発酵によってVFAが産生されるといえる． ―キーワード：糞中乳酸，糞pH，糞中VFA，腸内発酵，新生子馬． --------------------日獣会誌　55，417〜420（2002） Concentrations of Fecal Volatile Fatty Acid and Lactic Acid in Neonatal Foals Hiroshi SATO†, Takashi KUROSAWA and Shin OIKAWA School of Veterinary Medicine, Rakuno Gakuen University, 582 Midorimachi, Bunkyodai, Ebetsu 069-8501, Japan SUMMARY 　To clarify intestinal fermentation in newborn foals, fecal pH, volatile fatty acid (VFA), and lactic acid were analyzed in 113 fecal samples from 40 nursing neonates between birth and 7 weeks of age. Average values were fecal pH―7.52, VFA―0.26%, and lactic acid―0.01% (fresh basis). Mean molar ratios were as follows: acetic acid 64%, propionic acid 21%, and butyric acid 15%. Large individual differences were observed in fecal pH, lactic acid, and VFA levels and ratios. Though fetal feces on birth day contained less VFA, fecal-VFA levels tended to rise thereafter, with maximum concentration occurring from 1 day to 1 week of age. Extremely high concentrations of lactic acid occurred in some fecal samples on 0 and 1 day and 1 week of age. After declining at 1 week of age, fecal pH then tended to increase. It was concluded that it is possible for gut fermentation to produce VFA in neonatal foals immediately after colostrum feeding. ―Key words : fecal lactic acid, fecal pH, fecal VFA, gut fermentation, neonatal foal. †　Correspondence to : Hiroshi SATO (School of Veterinary Medicine, Rakuno Gakuen University) 582 Midorimachi, Bunkyodai, Ebetsu 069-8501, Japan TEL 011-388-4819 FAX 011-387-5890 --------------------J. Jpn. Vet. Med. Assoc., 55, 417〜420 (2002)