Effects of xylanase and probiotic supplementation on broiler chicken diets

ABSTRACT The objective of the present study was to evaluate the effects of xylanase and probiotic supplementation on the performance, carcass characteristics, intestinal pH, intestinal viscosity, and ileal microbiota of broiler chickens fed diets containing wheat bran. The study animals were kept in metal cages, and the study was performed using a completely randomized design, with four treatments, six birds per treatment, and six replicates. The four treatments included a control group, a probiotic-supplemented group, a xylanase-supplemented group, and a group that received both xylanase and probiotic supplementation. The diets of all four groups contained wheat bran (50 and 30 g/kg for the starter and grower phases, respectively) and phytase, and at 10 d after hatching, the experimental birds were challenged orally with Eimeria sp commercial vaccine. During the initial phase, supplementation with xylanase, probiotics, or their combination yielded greater weight gains than the control diet; however, considering the period from 10-35 d, the chickens receiving xylanase + probiotic and the diet without the additives showed lower weight gain (2.746 and 2.600 kg, respectively). All the supplemented diets reduced cecum viscosity, and supplementation with probiotic showed a significantly lower pH (6.11). The ileal microbiota was also influenced by xylanase and probiotic supplementation, modulating the frequencies of the genera Lactobacillus and Clostridium. The positive effects of supplementation with xylanase or probiotics alone were similar to those of co-supplementation, and no associative effect was observed.

摘要 本研究旨在评估添加木聚糖酶（xylanase）与益生菌（probiotic）对饲喂含麦麸日粮的肉用仔鸡生产性能、屠宰特性、肠道pH值、肠道黏度及回肠微生物群的影响。试验动物饲养于金属笼中，试验采用完全随机设计，设置4个处理组，每组6只试验鸡，共6个重复。4个处理组分别为对照组、益生菌添加组、木聚糖酶添加组以及同时添加木聚糖酶与益生菌的联合添加组。4组试验日粮均添加麦麸（育雏期和育成期分别为50 g/kg和30 g/kg）与植酸酶（phytase）；雏鸡于孵化后10 d经口接种艾美耳球虫（Eimeria sp.）商用疫苗。育雏期内，添加木聚糖酶、益生菌或二者联合使用的试验组，其增重均高于对照组日粮饲喂组；但在10~35 d的试验周期内，饲喂联合添加组日粮与无添加剂对照组的肉用仔鸡增重较低，分别为2.746 kg和2.600 kg。所有添加型日粮均降低了盲肠黏度，且益生菌添加组的肠道pH值显著更低，为6.11。木聚糖酶与益生菌添加同样对回肠微生物群产生影响，可调节乳杆菌属（Lactobacillus）与梭菌属（Clostridium）的相对丰度。单独添加木聚糖酶或益生菌的正向效果与联合添加组相当，未观察到协同增效作用。