作 者：
陈青;王洪荣;葛汝方;崔慧慧;王梦芝;喻礼怀;林淼
关键词：
物理有效中性洗涤纤维;采食量;瘤胃液pH;氨态氮;挥发性脂肪酸;纤维降解菌;后备奶牛
摘 要：
本文旨在研究不同物理有效中性洗涤纤维(peNDF)水平饲粮对8~10月龄奶牛采食量、瘤胃发酵参数和纤维降解菌的影响。选取24头月龄和体重相近的健康中国荷斯坦奶牛后备奶牛,随机分为4组,每组6个重复,每个重复1头。通过改变饲粮中粗料羊草的长度来改变peNDF水平。采用单因子试验设计,分别饲喂peNDF1.18实测水平为22.73%、23.92%、25.85%和28.39%的4种饲粮,预试期10d,正试期60d。结果显示:1)peNDF水平对各组干物质(DM)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)采食量均无显著影响(P>0.05)。2)瘤胃液pH随着peNDF水平的增加而增加,22.73%组极显著低于其他3组(P<0.01);peNDF水平对总挥发性脂肪酸浓度、乙酸和丁酸含量的影响不显著(P>0.05);丙酸含量总体上随着peNDF水平的增加而降低,22.73%组极显著高于23.92%组(P<0.01)、显著高于28.39%组(P<0.05);23.92%组的乙酸/丙酸极显著高于22.73%组(P<0.01)、显著高于25.85%组(P<0.05);25.85%组氨态氮浓度显著或极显著高于其他3组(P<0.05或P<0.01)。3)以22.73%组为对照,其他3组产琥珀酸丝状杆菌的相对含量随peNDF水平的增加而增加,28.39%组最高,但仍极显著低于22.73%组(P<0.01);随peNDF水平的增加,黄色瘤胃球菌、白色瘤胃球菌和溶纤维丁酸弧菌相对含量呈现先上升后下降的趋势,均为25.85%组最高,显著或极显著高于其他3组(P<0.05或P<0.01)。综上,适当提高饲粮peNDF水平,有利于提高8~10月龄奶牛瘤胃液pH,改善瘤胃发酵,增加瘤胃中纤维降解菌的含量;本试验条件下,peNDF1.18为25.85%是8~10月龄荷斯坦奶牛适宜的peNDF水平。
译 名：
Effects of Dietary Physically Effective Neutral Detergent Fiber Level on Rumen Fermentation Parameters and Cellulolytic Bacteria of 8 to 10-Month-Old Heifers
作 者：
CHEN Qing;WANG Hongrong;GE Rufang;CUI Huihui;WANG Mengzhi;YU Lihuai;LIN Miao;College of Animal Science and Technology,Yangzhou University;
关键词：
peNDF;;feed intake;;rumen fluid pH;;ammonia nitrogen;;volatile fatty acid;;cellulolytic bacteria;;heifers
摘 要：
The objective of this experiment was to evaluate effects of dietary physically effective neutral detergent fiber(pe NDF) level on rumen fermentation parameters and cellulolytic bacteria of 8 to 10-month-old heifers.Twenty-four Chinese Holstein heifers with similar month of age and body weight were randomly divided into 4groups.Heifers were offered one of four diets,which were chemically identical but included different pe NDF levels [22.73%,23.92%,25.85% and 28.39%]through cutting the roughage of Chinese wildrye into different lengths.The pre-test lasted for 10 days,and the test lasted for 60 days.The results showed as follows: 1)the intakes of dry matter,neutral detergent fiber and acid detergent fiber of heifers were not significantly affected by pe NDF level(P > 0.05).2) Rumen fluid pH increased with the increasing pe NDF level,22.73% group was significantly lower than the other 3 groups(P < 0.01); there were no effects of pe NDF level on total volatile fatty acid concentration,and acetate and butyrate contents(P > 0.05),however,with the increasing of pe NDF level,propionate content decreased,and 22.73% group was significantly higher than 23.92% group(P < 0.01)and 28.39% group(P < 0.05); the ratio of acetate to propionate of 23.92% group was significantly higher than that of 22.73% group(P < 0.01) and 25.85% group(P < 0.05); ammonia-N concentration of 25.85% group was significantly higher than that of the other 3 groups(P < 0.01 or P < 0.01).3) Using 22.73% group as control,the relative content of Fibrobacter succinogene of the other 3 groups was increased with increasing pe NDF level,and that of 28.39% group was the highest,but was still significantly lower than that of 22.73%group(P < 0.01); with the increasing of pe NDF level,the relative content of Ruminococcus flave faciensk,Ruminococcus Albus and Prevotella rumicola increased initially and then decreased,and the highest contents all appeared in 25.85% group,which were significantly higher than those of the other 3 groups(P < 0.05 or P < 0.01).It is concluded that properly increasing of dietary pe NDF level is beneficial for improvement of rumen fluid pH and rumen fermentation,as well as the content of cellulolytic bacteria in rumen; under the conditions in the present study,25.85% is the optimal pe NDF1.18 level in diets for 8 to 10-month-old heifers.
