德州驴盲结肠食糜液中纤维降解酶活性与挥发性脂肪酸含量的比较分析

本试验旨在比较分析德州驴盲结肠食糜液中纤维降解酶活性以及挥发性脂肪酸(VFA)的含量。采集9头德州驴的盲肠、腹结肠和背结肠食糜液样品,经4层纱布过滤后,通过分光光度计法测定羧甲基纤维素酶(CMCase)、微晶纤维素酶(AVI)、木聚糖纤维素酶(Xlyse)、阿魏酸酯酶(FAE)和乙酰酯酶(AE)活性,此外,使用气相色谱法测定VFA含量,每个指标3个平行。结果表明:CMCase、AVI与Xlyse活性在驴盲肠、腹结肠和背结肠食糜液中依次增加(P<0.05),而FAE活性在驴盲结肠间无显著差异(P>0.05)。驴背结肠食糜液中AE活性显著高于盲肠与腹结肠(P<0.05)。乙酸摩尔比例在驴盲肠、腹结肠和背结肠食糜液中依次显著增加(P<0.05),丙酸摩尔比例依次降低(P<0.05)。而且驴结肠食糜液中支链VFA含量显著高于盲肠(P<0.05)。综上所述,本研究明确了驴盲结肠食糜液具有较高的催化水解饲料细胞壁半纤维素与木质素分子间酯键连接的FAE和AE活性,随着驴后肠段逐渐后移,驴盲肠、腹结肠与背结肠食糜液中乙酸摩尔比例依次增加,丙酸摩尔比例依次降低。

Comparative Analysis of Cellulase Activity and Volatile Fatty Acid Contents in Cecum and Colon Chyme Liquid of Dezhou Donkey

In order to determine the cellulase activities and the contents of volatile fatty acids(VFA)in the hindgut of donkeys,chyme liquid samples from cecum,ventral colon and dorsal colon of 9 Dezhou donkeys were collected and filtered by 4-layer gauze. The activities of carboxymethyl cellulase(CMCase),microcrystalline cellulase(AVI),xylan cellulase(Xylase),ferulic esterase(FAE)and acetylesterase(AE)were measured by spectrophotometer for three times. The results showed that the activities of CMCase,AVI and Xlyase increased gradually in cecum,ventral colon and dorsal colon chyme liquid(P<0.05),but there was no significant difference for the activity of FAE between the cecum and ventral colon chyme liquid. The AE activity in dorsal colon chyme liquid was significantly higher than that in cecum and ventral colon(P>0.05). In addition,the VFA content was determined through gas chromatograph. The molar ration of acetate was increased gradually in cecum,ventral colon and dorsal colon chyme liquid(P<0.05),while the molar ration of propionic acids was gradually decreased(P < 0. 05). In summary,it is confirmed that donkey cecum and colon chyme liquid has higher FAE and AE activities for catalytic hydrolysis of cell wall hemicellulose and intermolecular ester bond of lignin;in addition,the molar ration of acetate is gradually increased while the molar ration of propionate is decreased in donkey cecum,ventral colon and dorsal colon chyme liquid.Chinese Journal of Animal Nutrition,2022,34(2):1151-1157]