INFLUENCE OF ADDITION OF YEAST CULTURE SUPPLEMENT TO DIETS OF LACTATING COWS ON RUMINAL FERMENTATION AND MICROBIAL-POPULATIONS
INFLUENCE OF ADDITION OF YEAST CULTURE SUPPLEMENT TO DIETS OF LACTATING COWS ON RUMINAL FERMENTATION AND MICROBIAL-POPULATIONS
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DOI：
10.3168/jds.s0022-0302(88)79894-x
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发表时间：
1988-11-01
影响因子：
3.5
通讯作者：
BARKER, KB
中科院分区：
文献类型：
--
作者：
HARRISON, GA;HEMKEN, RW;BARKER, KB
采用随机区组设计，研究了添加酵母培养物对奶牛瘤胃代谢和表观消化率的影响。奶牛饲喂40%玉米青贮饲料和60%精料（DM基础）的饮食。处理是对照（不含酵母细胞的补充物）和酵母培养物补充物。疗程均为6wk。瘤胃pH值，氨，乙酸盐和异戊酸盐的摩尔比例，乙酸盐：丙酸盐的比例较低，丙酸盐和戊酸盐的摩尔比例较高的奶牛接受酵母。厌氧细菌的浓度往往更高，纤维素分解菌浓度更大的奶牛饲喂酵母比奶牛接受控制饮食。补充酵母不影响异丁酸或丁酸，总VFA，或在瘤胃液中的活酵母浓度的摩尔比例。瘤胃液稀释率和全消化道表观消化率在处理间无差异。纤维素在体外的消失率较低的奶牛接受酵母。氨浓度和微生物数量的变化较小，表明接受酵母培养物补充的奶牛瘤胃发酵更稳定。
Six ruminally fistulated Holstein cows were utilized in a randomized block design to examine effects of yeast culture supplement on ruminal metabolism and apparent digestibility. Cows were fed a diet of 40% corn silage and 60% concentrate (DM basis). Treatments were control (supplement without yeast cells) and yeast culture supplement. Treatment periods were 6 wk. Ruminal pH, ammonia, molar proportions of acetate and isovalerate, and acetate:propionate ratio were lower and molar proportions of propionate and valerate higher in cows receiving yeast. The concentration of anaerobic bacteria tended to be higher and cellulolytic bacteria concentrations were greater in cows fed yeast than in cows receiving control diet. Supplemental yeast did not affect molar proportions of isobutyrate or butyrate, total VFA, or viable yeast concentrations in ruminal fluid. Ruminal liquid dilution rate and total tract apparent digestibilities were not different between treatments. Rate of disappearance of cellulose in vitro was lower in cows receiving yeast. Less variation in ammonia concentrations and microbial numbers suggest that ruminal fermentation was more stable in cows receiving yeast culture supplement.