本文旨在研究玉米芯-柑橘渣混合青贮料对肉牛生长性能、养分消化率和血清生化指标的影响。选择24头平均体重（173.13±5.10） kg的健康西门塔尔杂种肉牛，随机分为4个处理，每个处理6个重复，每个重复1头牛，饲养时间为50 d。4个处理分别是：1）对照组（CON），40%精料+60%牛鞭草；2）试验1组（S20），40%精料+40%牛鞭草+20%青贮料（玉米芯-柑橘渣混合青贮料）；3）试验2组（S30），40%精料+30%牛鞭草+30%青贮料；4）试验3组（S40），40%精料+20%牛鞭草+40%青贮料。结果表明，S20组平均日增重最高，比CON组提高17.14%（P<0.01），S30组干物质采食量最高，比CON组提高14.51%（P<0.05），S20组肉牛料重比最低（P>0.05）。4个处理间干物质、粗蛋白质、中性洗涤纤维和酸性洗涤纤维的表观消化率无显著差异（P>0.05），但是S20组有机物的消化率显著高于CON组（P<0.05）。各处理间总蛋白、葡萄糖含量无显著差异（P>0.05），3个试验组尿素氮含量均极显著低于CON组（P<0.01），分别降低了23.09%、26.10%和30.32%。由此可知，玉米芯-柑橘渣混合青贮料替代部分牛鞭草能提高肉牛生长性能，主要表现在提高肉牛采食量、平均日增重和养分消化率上。玉米芯-柑橘渣混合青贮料的添加量以占饲粮的20%为宜。

This study was conducted to determine the effects of mixed silage with corncob and citrus pulp on growth performance, nutrient digestibility and serum biochemical parameters of beef cattle. A total of 24 healthy Simmental cross cattle with initial body weight of (173.13±5.10) kg were randomly allocated into 4 treatments with 6 replicates per treatment and 1 cattle per replicate. The feeding trial lasted for 50 days. Four treatments included 1) control group (CON), 40% basal diet+60% Hemathria sibirica; 2) test group 1 (S20), 40% basal diet+40% Hemathria sibirica+20% mixed silage; 3) test group 2 (S30), 40% basal diet+30% Hemathria sibirica+30% mixed silage; 4) test group 3 (S40), 40% basal diet+20% Hemathria sibirica+40% mixed silage. The results showed that the average daily gain of S20 group was increased by 17.14% compared with CON group (P<0.01). The dry matter intake of S30 group was improved by 14.51% compared with CON group (P<0.05). The S20 group had a lower ratio of feed to gain than the other three groups (P>0.05). No significant differences were observed in apparent digestibility of dry matter, crude protein, neutral detergent fiber and acid detergent fiber (P>0.05). The digestibility of organic matter of S20 group was significantly higher than that of CON group (P<0.05). No significant differences were observed in serum total protein and glucose contents (P>0.05). The serum urea nitrogen content was significantly decreased in S20, S30 and S40 groups than that in CON group by 23.08% (P<0.01), 26.09% (P<0.01) and 30.32% (P<0.01), respectively. In conclusion, the mixed silage with corncob and citrus pulp substituted of some Hemathria sibirica can increase the dry matter intake, average daily gain and nutrient digestibility, and improve the growth performance of beef cattle. Therefore, the study suggests that it is feasible when mixed silage with corncob and citrus pulp accounts for 20% in the beef cattle diet.［Chinese Journal of Animal Nutrition，2011，23（4）：647 -653］