饲粮不同NFC/NDF对肉用绵羊瘤胃pH、氨态氮和挥发性脂肪酸的影响

Effects of Dietary NFC/NDF Ratios on Rumen pH,NH3-N and VFA of Meat Sheep

本试验旨在研究饲粮不同非纤维性碳水化合物/中性洗涤纤维(NFC/NDF)对肉用绵羊瘤胃pH、氨态氮和挥发性脂肪酸的影响。选用(47.21±1.01)kg安装有瘤胃瘘管的杜泊羊()×小尾寒羊(♀)杂交1代肉用公羊12只,采用12×4不完全拉丁方设计,试验分4期进行,每期16 d,分别饲喂NFC/NDF为0.25、0.34、0.36、0.52、0.60、0.80、0.87、1.13、1.30、1.58、2.17和2.49的12种饲粮。结果表明:随着NFC/NDF的增加,试验羊瘤胃pH极显著线性降低(P<0.01),氨态氮浓度极显著线性增加(P<0.01),瘤胃总挥发性脂肪酸及丁酸比例呈显著三次曲线变化(P<0.05),总挥发性脂肪酸中的丙酸、戊酸和异戊酸比例极显著线性增加(P<0.01),乙酸比例和乙酸/丙酸极显著线性降低(P<0.01)。由此可见,饲粮NFC/NDF对瘤胃pH、氨态氮和挥发性脂肪酸具有显著影响。

This experiment was conducted to study the effects of dietary non-fiber carbohydrate to neutral detergent fiber(NFC/NDF) ratios on rumen pH,ammonia-N(NH3-N) and volatile fatty acid(VFA) of meat sheep.Twelve rumen-cannulated crossbred(Dorper ×Thin-tailed Han ♀) rams with body weight of(47.21±1.01) kg were divided into 12 groups(4 trial periods) and each period lasted for 16 days according to a 12×4 uncompleted Latin square experimental design.The rams were fed rations with different NFC/NDF ratios,which were 0.25,0.34,0.36,0.52,0.60,0.80,0.87,1.13,1.30,1.58,2.17 and 2.49,respectively.The results showed that with the increasing of NFC/NDF ratios,rumen pH was significantly linear decreased(P<0.01),rumen NH3-N was significantly linear increased(P<0.01),total volatile fatty acid(TVFA) and butyrate percent were changed obviously with cubic curve(P<0.05),percent of propionate,valerate and isovalerate in rumen were significantly linear increased(P<0.01),while acetate percent and acetate/propionate ratio were significantly linear decreased(P<0.01).These results indicate that dietary NFC/NDF ratios have significant effects on rumen pH,NH3-N and VFA.