【作者】 穆永胜；

【导师】 张石蕊； 戴求仲；

【作者基本信息】 湖南农业大学 ， 养殖， 2009， 硕士

【摘要】 为研究在玉米-豆粕-杂粕型日粮添加α-半乳糖苷酶制剂对黄羽肉鸡生产性能的影响及相关机理,选择500羽8日龄快长型黄羽肉鸡,随机分为5个组,每组设4个重复,每个重复25羽,试验分为前期（8～28日龄）和后期（29～56日龄）两个阶段。试验Ⅰ组饲喂正对照日粮（ME:前期11.92 MJ/kg,后期12.34 MJ/kg）,试验Ⅱ组饲喂负对照日粮（ME:前期11.71 MJ/kg,后期12.13 MJ/kg）,试验Ⅲ～Ⅴ组分别饲喂在负对照日粮中添加100、150和200 mL/tα-半乳糖苷酶的试验日粮。试验结果表明:①各试验组间肉鸡的平均日增重、日采食量、前期和全期料重比和全期存活率均无明显差异（P＞0.05）,但添加α-半乳糖苷酶制剂的试验组后期料重比均低于正对照组（P＞0.05）和负对照组（P＜0.05）,而全期料重比也都低于正、负对照组（P＞0.05）;②各试验组间试鸡屠宰率、全净膛率无明显差异（P＞0.05）,但负对照组半净膛率明显较高,而腹脂率以正对照组最高;③3个加酶组的干物质、粗蛋白质、能量表观代谢率和表观代谢能均高于负对照组而接近于正对照组,各组间差异不显著（P＞0.05）;3个加酶组的缬氨酸、亮氨酸和赖氨酸表观消化率均显著高于负对照组（P＜0.05）,但总氨基酸表观消化率各组间差异不显著（P＞0.05）。④3个加酶组试鸡血液中GLU浓度均高于正、负对照组,且试验Ⅲ和Ⅴ组达到显著水平（P＜0.05）;BUN含量以负对照组最高,而T₃、T₄、INS和GH却以负对照组最低;⑤3个加酶组的胸腺指数、法氏囊指数以及血液中IgA和IgM水平较正、负对照组均有不同程度的提高。⑥α-半乳糖苷酶制剂显著降低了后肠大肠杆菌数（P＜0.05）,且增加了双歧杆菌数和乳酸菌数（P＜0.05）,其中大肠杆菌数随α-半乳糖苷酶添加剂量的增加呈递降趋势。可以结论,在黄羽肉鸡玉米-豆粕-杂粕型日粮中添加α-半乳糖苷酶制剂能够降低料重比、改善肠道菌群平衡,增强免疫功能,并提高肉鸡蛋白质和能量的利用效率,综合生产性能指标、养分利用率及添加成本,α-半乳糖苷酶的最适添加水平为100mL/t。更多还原

【Abstract】 The experiment was conducted to investigate the effect of different levels ofα-galactosidase supplementation on growth performance and its mechanism of Yellow broilers fed on corn-soybean meal-miscellaneous meal based diets. Five hundred 8-day-old yellow broilers were randomly assigned to five groups with four replicates and twenty-five chicks each pen. Experiment was divided into 2 periods (8～28 d and 29～56 d) and lasted 49 days. GroupⅠfed positive control diets (PC, ME: 8～28 d 11.92 MJ/kg, 29～56 d 12.34 MJ/kg); groupⅡfed negative control diets (NC, ME: 8～28 d 11.71 MJ/kg, 29～456 d 12.13 MJ/kg). GroupⅢ～Ⅴwere fed NC diets supplemented with 100, 150 and 200 mL/t ofα-galactosidase, respectively. The results showed:①The average daily weight gain (ADG), average daily feed intake (ADFI), 8～28 d feed to gain ratio (F/G) and survival rate were not significantly difference among five groups (P>0.05), but 29～56 d F/G in groupⅢ～Ⅴwas lower than that in NC group (P<0.05) and PC group CP>0.05), and 8～56 d F/G in groupⅢ～Ⅴalso lower than that in NC group (P>0.05) and PC group (P>0.05).②The dressing percentage and percentage of eviscerated yield were not significantly difference among five groups (P>0.05), but the percentage of half-eviscerated yield in NC group was little higher than that in other groups and the percent of abdominal fat in PC group was the highest one among five groups.③The apparent metabolizability of DM, CP and energy and the apparent metabolizable energy in groupⅢ～Ⅴwere little higher than that in NC group (P>0.05) and closed to or little higher than that in PC group (P>0.05). The apparent digestibility of Val, Leu and Lys in groupⅢ～Ⅴwere significantly higher than that in NC group (P<0.05), but the apparent digestibility of total AA had no significant difference among five groups (P>0.05).④The concentration of blood glucose in groupⅢ～Ⅴwere higher than that in PC and NC group and there were significantly difference among groupⅢ,Ⅴand PC, NC group (P<0.05). The concentration of blood urea nitrogen in NC group was the highest one among five groups, but the concentrations of T3, T4, INS and GH in blood in NC group were the lowest one among five groups.⑤The thymus index, index of bursa of fabricius, the level of IgA and IgM in groupⅢ～Ⅴwere little higher than that in PC and NC group.⑥α-galactosidase significantly increased the number of bifidobacterium and lactobacillus in caecum (P<0.05), whereas reduced the number of caecal coliform bacteria (P<0.05).In conclusion, fed Yellow broilers with corn-soybean meal-miscellaneous meal based diets supplemented withα-galactosidase could decrease feed/gain ratio, improve intestinal microbial balance, and increase immunity function, as well as availability of protein and energy. As evaluated with the performance index, nutrients availability and cost, the best supplementation dose for this experiment was 100ml/t.更多还原