Effect of Saccharomyces cerevisiae on alfalfa nutrient degradation characteristics and rumen microbial populations of steers fed diets with different concentrate-to-forage ratios

作     者：Gengzhi Ding Ying Chang Liping Zhao Zhenming Zhou Liping Ren Qingxiang Meng 

作者机构：State Key Laboratory of Animal NutritionCollege of Animal Science and TechnologyChina Agricultural University Lallemand biology Technology(Beijing) Co.Ltd. 

出 版 物：《Journal of Animal Science and Biotechnology》 (畜牧与生物技术杂志（英文版）)

年 卷 期：2014年第5卷第4期

页      面：430-438页

核心收录：

学科分类：090502[农学-动物营养与饲料科学] 0905[农学-畜牧学] 09[农学] 

基　　金：financially supported by the Earmarked Fund for ModernAgro-Industry Technology Research System(Beef Cattle and Yaks,CARS-38) the Chinese Universities Scientific Fund(No.2013QT034) 

主　　题：Concentrate to forage ratios In situ Real time PCR Rumen microorganism Steers 

摘      要：Live yeast（Saccharomyces cerevisiae） constitutes an effective additive for animal production;its probiotic effect may be related to the concentrate-to-forage ratio（CTFR）.The objective of this study was to assess the effects of ***（SC） on fiber degradation and rumen microbial populations in steers fed diets with different levels of dietary *** Simmental × Local crossbred steers（450 ± 50 kg BW） were assigned to a control group or an SC *** groups were fed the same basal diet but the SC group received SC supplementation（8 × 10^9 cfu/h/d through the ruminal fistula）following a two-period crossover *** period consisted of four phases,each of which lasted 17 d：10 d for dietary adaptation,6 d for degradation study,and 1 d for rumen sample *** the 1^（st） to the 4^（th） phase,steers were fed in a stepwise fashion with increasing CTFRs,i.e.,30：70,50：50,70：30,and 90：*** kinetics of dry matter and fiber degradation of alfalfa pellets were evaluated;the rumen microbial populations were detected using real-time *** results revealed no significant（P〉 0.05） interactions between dietary CTFR and SC for most *** CTFR had a significant effect（P〈 0.01） on degradation characteristics of alfalfa pellets and the copies of rumen microorganism;the increasing concentrate level resulted in linear,quadratic or cubic variation trend for these *** supplementation significantly（P〈 0.05） affected dry matter（DM） and neutral detergent fiber（NDF）degradation rates（c_（DM）,c_（NDF）） and NDF effective degradability（ED_（NDF））.Compared with the control group,there was an increasing trend of rumen fungi and protozoa in SC group（P 〈 0.1）;copies of total bacteria in SC group were significantly higher（P〈 0.05）.Additionally,percentage of Ruminobacter amylophilus was significantly lower（P〈 0.05）but percentage of Selenomonas ruminantium was significantly higher（P〈 0.05） in the SC *** a word,dietary CTFR had a significant effect on