小麦基础饲粮中添加木聚糖酶对生长猪生长性能、血清生化指标及肠道微生物菌群的影响

摘要

本试验旨在研究在小麦基础饲粮中添加木聚糖酶对生长猪生长性能、营养物质表观消化率、血清生化指标及肠道微生物菌群的影响,探讨适宜的木聚糖酶添加水平.选择80头健康、平均体重40 kg的“杜×长×大”生长猪,随机分为5个处理,每个处理4个重复,每个重复4头猪.正对照组饲喂玉米-豆粕型基础饲粮,负对照组饲喂小麦-豆粕型基础饲粮,木聚糖酶组分别饲喂在负对照基础饲粮上添加500、1 000和2 000 U/kg木聚糖酶的试验饲粮.试验期28 d.结果表明:1)小麦基础饲粮中添加木聚糖酶可极显著提高生长猪平均日增重(P＜0.01),显著或极显著提高平均日采食量和营养物质表观消化率(P＜0.05或P＜0.01),其中2 000 U/kg木聚糖酶组效果最好,平均日增重和平均日采食量分别提高了26.0％和16.5％(P＜0.01)；2)小麦基础饲粮中添加木聚糖酶显著或极显著提高了生长猪血清葡萄糖、三碘甲腺原氨酸、四碘甲腺原氨酸和D-木糖含量(P＜0.05或P＜0.01),极显著降低血清尿素氮含量(P＜0.01)；3)饲粮组成和木聚糖酶可显著影响猪肠道微生物菌群,添加木聚糖酶可维持动物肠道微生物菌群的平衡,2 000 U/kg木聚糖酶组肠道菌群结构和玉米-豆粕饲粮饲喂条件下接近.由此可见,添加2 000 U/kg的木聚糖酶可显著改善饲喂小麦基础饲粮生长猪的生长性能和营养物质表观消化率,维持肠道微生物菌群的平衡.在木聚糖含量为11.2％的生长猪小麦基础饲粮中,木聚糖酶的适宜添加水平为2 000 U/kg.%This experiment was conducted to investigate the effects of wheat-based diets supplemented with xylanase on growth performance, nutrient apparent digestibility , serum biochemical parameters and intestinal microbial flora of growing pigs, and to explore the optimal level of xylanase. A total of eighty healthy crossbred pigs (Duroc x Landrace x Large) with an average bodyweight of 40 kg were randomly allotted into 5 treatments with 4 replicates per treatment and 4 pigs per replicate. Pigs in positive control group were fed the corn-soybean basal diet, pigs in negative control group were fed the wheat-soybean basal diet, and the others in xylanase groups were fed the wheat-soybean basal diet supplemented with 500, 1 000 and 2 000 U/kg xylanase, respectively. The experiment lasted for 28 days. The results showed as follows; 1) the wheat-soybean basal diet supplemented with xylanase significantly increased the average daily gain (P<0.01) , average daily feed intake (P <0. 05) and nutrient apparent digestibility (P <0. 05) of growing pigs, and the best results were obtained at 2 000 U/kg xylanase group, the average daily gain and average daily feed intake were increased by 26.0% and 16.5% (P<0. 01). 2) The wheat-soybean basal diet supplemented with xylanase significantly increased the contents of glucose, triiodothyronine, thyroxine, and O-xylose in serum of growing pigs ( P < 0.05, P <0. 01) , while significantly decreased the serum urea nitrogen content (P <0. 01). 3) The intestinal microbial flora was affected by dietary composition and xylanase, diets supplemented with xylanase could maintain the microflora balance for pigs, and the composition of intestinal flora by adding 2 000 U/kg xylanase was similar to the corn-soybean basal diet. In conclusion, adding 2 000 U/kg xylanase can significantly improve the growth performance and nutrient apparent digestibility of pigs that fed with wheat-soybean basal diet, and maintain the balance of intestinal flora. The optimal level of xylanase for growing pigs in the wheat-soybean basal diet (containing 11.2% xylan) is 2 000 U/kg. [ Chinese Journal of Animal Nutrition, 2012, 24 (10) : 1920-1927]