中文摘要：

将9只体况良好，体重相近（41.3±1.2kg），安装有永久性瘤胃瘘管的成都麻羊半同胞羯羊，随机分成3组，饲以稻草基础日粮，分别补饲25%（MSL25）、50%（MSL50）与75%（MSL75）的苜蓿（MSL），在进行增重性能的组合效应研究的同时，采集各组瘤胃液以获取瘤胃原虫和细菌，用4,6-二脒基-2-苯基吲哚（DAPI）标记细菌的荧光强度，进行瘤胃原虫对细菌吞噬作用的组合效应研究。结果显示：（1）瘤胃原虫的细菌吞噬量与吞噬速率均随苜蓿补饲水平的增加而减少，当补饲水平达到50%时，趋于平稳。各补饲水平组的吞噬量在60 min达到饱和，此时吞噬量自高到低的排序为MSL25（381.91）＞MSL50（377.02）＞MSL50（376.47）。（2）MSL25、MSL50与MSL75的日增重分别为19.14 g/d、40.40 g/d与49.26g/d（P＜0.05）；②MSL25、MSL50与MSL75单位增重所需的饲料分别为44.14、23.69与21.26，其中MSL50与MSL75的组间差异不显著（P＞0.05）；MSL25、MSL50与MSL75每千克增重饲料成本分别为58.49元、48.56元与59.01元，其中MSL25与MSL75的组间差异不显著（P＞0.05）。研究结果表明，山羊稻草基础日粮补饲50%的苜蓿可提高瘤胃内蛋白微循环效率、改善增重性能、降低饲料成本。

英文摘要：

Nine healthy Chengdu Ma wether Goats from sire half-sib family with similar weight, were divided into three groups randomly and fed with the rice straw （RS） supplemented with 25% （ MSL25）, 50% （ MSL50） and 75% （MSL75） alfalfa hay （Medicago sativa Linn, MSL） respectively to obtain rumen protozoa and bacteria for determinating the phagocytosis of rumen protozoa on bacteria during the study of associative effects on weight gains. The lfuorescence intensity of bacteria labeled by DAPA was tested in this study. The results showed that：A. for the phagocytosis of rumen protozoa on bacteria, the grazing quantity and grazing rate decreased with increasing level of MSL, and then lfattens-off as the supplemented level of MSL reached 50%. The grazing quantity reached saturation at 60 min for 3 mixed forages and ranked from greatest to least as follows： MSL25 （381.91）〉MSL50 （377.02）〉MSL50 （376.47）, the ifgures in parentheses were grazing quantity, and the units were cells/cell. B. for associative effects on weight gains：a. the daily gains of MSL25, MSL50 and MSL50 were 19.14 g/d, 40.40 g/d and 49.26g/d respectively （P〈0.05）; b. the Feed / Gain of MSL25, MSL50 and MSL50 were 44.14, 23.69 and 21.26 respectively, no signiifcant difference between MSL50 and MSL75 was observed;c. the Feed cost/Gain of MSL25, MSL50 and MSL50 were 58.49 yuan/kg,48.56 yuan/kg and 59.01 yuan/kg respectively, no signiifcant difference between MSL25 and MSL75 was observed. It was concluded that the efifciency of rumen protein microcirculation and the daily gains of goats could be improved when the goat rice straw basic diet supplemented with 50%MSL.