Effect of Non-Starch Polysaccharide (NSP) of Wheat and Barley Supplemented with Exogenous Enzyme Blend on Growth Performance, Gut Microbial, Pancreatic Enzyme Activities, Expression of Glucose Transporter (SGLT1) and Mucin Producer (MUC2) Genes of Broiler Chickens

ABSTRACT The experiment was carried out in a completely randomized design (CRD) with 625 broiler chicks (Ross 308) for 5 repetitions (25 birds per each replicated) on the 5 treatments diet. Treatments included two different types of cereal grains (wheat, and barley) with or without an enzyme supplementation along with a corn-based diet as control group. The experimental diets were formulated to have similar contents of crude protein, metabolizable energy, total non-starch polysaccharides (NSP) and were fed in two periods of starter and grower. Experimental traits were consisted growth performance, ileal flora numeration, villus morphology in 3 parts of the intestine, digesta viscosity and pancreatic enzyme activity, and determining the gene expression level of glucose transporter (SGLT1) and mucin producer (MUC2) in the jejunum. Results indicated that inclusion of wheat and barley to corn-soy based diet with or without exo-enzymes blend on growth performance traits were significant (p<0.01). Feed intake and average daily gain in wheat diet was lower, conversely FCR was higher than other groups (p<0.01). Maximum microbial count were observed in wheat and barley diets and minimum were observed in enzyme supplemented diets respectively (p<0.01). Control group and enzyme supplemented diets had minimum counting of gram negative, coliform and clostridium, but maximum counting of lactobacilli and bifidobacter were observed in enzyme supplemented diets (p<0.01). Viscosity and activities of pancreatic a-amylase and lipase were significantly increased in chicks fed wheat and barley when compared to the control group fed on corn (p<0.01). Feeding wheat and barley diets reduced villus height in different parts of the small intestine when compared to those fed on a corn diet (p<0.01). Gene expression level of glucose transporter (SGLT1) and mucin producer (MUC2) in jejunum was significantly affected by the inclusion of wheat and barley to corn-soy based diet with or without exo-enzymes blend (p<0.01). In conclusion, the inclusion of wheat and barley to corn-soy based diet without enzyme supplementation has an adverse effect on growth, ileal microflora villi morphology, digesta viscosity, pancreatic enzyme activity, and gene expression level of nutrient transporters. However, enzyme supplemented to wheat and barley diets significantly improved those traits, and restored the negative effects.

摘要 本试验采用完全随机设计（completely randomized design, CRD），选取625只Ross 308肉鸡，设置5种试验日粮组，共5个重复组，每个重复组25只肉鸡。试验日粮包含两种不同谷物籽粒（小麦、大麦），分别添加与不添加酶制剂，另设玉米基础日粮组作为对照组。所有试验日粮均配置为粗蛋白、代谢能、总非淀粉多糖（total non-starch polysaccharides, NSP）含量一致，并分为育雏期与育成期两个阶段饲喂。试验测定指标包括生长性能、回肠菌群计数、肠道3个部位的肠绒毛形态、食糜黏度、胰酶活性，以及空肠内葡萄糖转运蛋白（SGLT1）和黏蛋白生成基因（MUC2）的基因表达水平。结果显示，在玉米-大豆基础日粮中添加小麦或大麦（无论是否添加复合外源酶制剂），对生长性能指标均有极显著影响（p<0.01）。小麦日粮组的采食量与平均日增重均低于其他组，而料重比（Feed Conversion Ratio, FCR）则高于其他组（p<0.01）。小麦与大麦日粮组的菌群总数最高，添加酶制剂的日粮组菌群总数最低（p<0.01）。对照组与添加酶制剂的日粮组革兰氏阴性菌、大肠菌群及梭菌属计数最低，而乳杆菌属与双歧杆菌属计数则在添加酶制剂的日粮组中达到最高（p<0.01）。与饲喂玉米基础日粮的对照组肉鸡相比，饲喂小麦与大麦日粮的肉鸡其食糜黏度及胰α-淀粉酶、脂肪酶活性均极显著升高（p<0.01）。饲喂小麦与大麦日粮组肉鸡的小肠各部位肠绒毛高度均低于玉米日粮组（p<0.01）。在玉米-大豆基础日粮中添加小麦或大麦（无论是否添加复合外源酶制剂），均会极显著影响空肠内葡萄糖转运蛋白（SGLT1）和黏蛋白生成基因（MUC2）的基因表达水平（p<0.01）。综上，在玉米-大豆基础日粮中不添加酶制剂而直接添加小麦或大麦，会对生长性能、回肠菌群、肠绒毛形态、食糜黏度、胰酶活性以及营养转运蛋白基因表达水平产生不利影响。但在小麦与大麦日粮中添加酶制剂，可极显著改善上述指标，抵消其带来的负面效应。