【作者】 易昌华；

【导师】 贺建华；

【作者基本信息】 湖南农业大学 ， 动物营养与饲料科学， 2004， 硕士

【摘要】 本试验研究了不同添加水平的CLA对艾维因肉鸡的营养重分配作用以及对肉鸡生产性能、体内脂质代谢、免疫功能以及腹脂和胸腿肌脂肪酸组成的影响，并进一步探讨了其作用机理。试验选用健康、体重接近的艾维因肉鸡360羽(公母各半)(P＞0.05)。按单因素完全随机设计分为5个处理，每处理设3个重复共72只鸡，进行为期49天的饲养试验。5个处理组中纯CLA含量分别为CLA 0％、0.5％、1.0％、1.5％、2.0％(CLA油中纯CLA含量为80％)。具体分组情况如下： Ⅰ组(对照组)：饲喂基础日粮(其中日粮中豆油的含量为2.5％；CLA含量为0.00％) Ⅱ组(0.50％CLA添加组)：用0.625％CLA油取代基础日粮相应比例的豆油(其中日粮中豆油的含量为1.875％：CLA含量为0.50％) Ⅲ组(1.00％CLA添加组)：用1.25％CLA油取代基础日粮相应比例的豆油(其中日粮中豆油的含量为1.25％：CLA含量为1.00％) Ⅳ组(1.50％CLA添加组)：用1.875％CLA油取代基础日粮相应比例的豆油(其中同粮中豆油的含量为0.625％；CLA含量为1.50％) Ⅴ组(2.00％CLA添加组)：用2.50％CLA油取代基础日粮相应比例的豆油(其中日粮中豆汕的含量为0.00％，CLA含量为2.00％) 试验结果表明： 1)、CLA具有一定的营养重分配作用，能降低腹脂率，提高肉鸡胸腿肌比率，并同时增加胸肌中脂肪含量和蛋白质含量，改善肌肉品质。血液生化结果表明：CLA的营养重分配作用可能是通过影响肉鸡体内生长激素、胰岛素和甲状腺素的分泌而实现的。 2)、CLA对肉鸡体脂组成的影响实际是增加肉鸡体脂中饱和脂肪酸和CLA的含量(p＜0.05)，降低单不饱和脂肪酸的含量(p＜0.05)，而并不影响多不饱和脂肪酸的含量。同时血脂测定结果表明，CLA能够提高HDL／LDL的比值，但差异不显著(P＞0.05)，这表明CLA可能具有一定的抗动脉硬化功效。但仍需进一步试验证明。 3)、在肉鸡的整个生长期内，适量添加CLA能够提高肉鸡的平均重、平均日增重和饲料转化效率，低剂量CLA(0.5、1.0和1.5％)不影响肉鸡采食量，当CLA添加水平达2％时，在肉鸡的生长前期(0-35d)，明显降低了肉鸡的采食量和平均日增重(p＜0.05)，抑制了肉鸡的生长。尽管在生长后期当肉鸡适应日粮之后，能显著提高平均日增重(p<0.()5)，但由于肉鸡前期生长受到过度抑制，因而影响了整个生长期的生长。4)、免疫指标测定结果表明:CLA能够促进免疫器官发育，增强肉鸡体液免疫和细胞免疫功能。，5)、根据以上结果，建议在肉鸡日粮中添加1.0%C以。更多还原

【Abstract】 The experiment was conducted to examine the effects of different conjugated linoleic acid(CLA) levels on nutrient repartition, growth performance, lipid metabolism, immunity competence, fatty acid composition in belly fat and breast & thigh muscle of Avain broiler chickens, and furtherly to investigate the function mechanism of CLA on above parameters. Three hundred and sixty Avain broilers (180^,180$) with the similar initial body weight (P>0.05) were averagely assigned to five groups with three replications (72 broilers) per group according to a Completely Random Design. The whole experiment lasted for 49 days. Different groups were fed diets with different CLA levels(0,0.5%,1.0 0%,1. 50% and 2.0 0%)., Which was supplied by the CLA oil.(containing 80% CLA). The details were as follows: Group I (the control group): the basal diet (containing 2.5% soybean oil and 0.00%CLA). Group II (0.50% CLA): 0.625% soybean oil in basal diet was substituted with 0.625%CLA oil (containing 1.875% soybean oil and 0.50% CLA) Group 111(1.00% CLA): 1.25% soybean oil in basal diet was substituted with 1.25%CLA oil(containing 1.25 soybean oil and 1.00% CLA). Group rV(1.50% CLA): 1.875% soybean oil in basal diet was substituted with 1.875%CLA oil (containing 0.625% soybean oil and 1.50% CLA). Group V(2.00% CLA): 2.50% soybean oil in basal diet was substituted with 2.50%CLA oil (containing 0.00% soybean oil and 2.00% CLA). The results showed that: (1) In the experiment, it was showed that CLA -had the function of nutritionalrepartition and could decrease the percentage of belly fat, increase the percentage of breast & thigh muscle, improve the content of fat and protein in the breast muscle, and elevate the meat quality of broilers. It was suggested that the nutritional repartitioning function of CLA was due to the elevated secretion of GH, INS, T3and T4.(2)Actually, SFA and CLA content of adipose tissue of broilers was significantly increased ( p < 0.05 ) and MUFA was significantly decreased ( p < 0.05) .however, CLA had no effect on PUFA(P>.05). The results of the composition of lipids in blood of broiler indicated that CLA could increase the ratio of HDL to LDL(P>0.05).It implied that CLA might has the effect of antiatherosclerosis, which needed to be justified.(3) Suitable content of CLA in the diets (below 1.50%) on the whole stage could improve average body weight, average daily gain and feed efficiency, and decrease the ratio of feed to gain, but had no significant effect on feed intake(P>0.05). Feed intake, average daily gain and growth performance were all restricted when the CLA in diets increased to 2% at the starter phase(0~35d). Although the average daily gain of broilers was significantly improved at the grower phase (36-49d) (p < 0. 05) when the broilers are adaptable to the diets, the growth performance on the whole stage was restrained because of the west restriction of 2% CLA at starter pahse..’(4) The results of immunity index indicated that CLA could stimulate the development of immune organs, improve the function of hormones immunity and cell-mediated immune competence.(5) Based on the above results, it is suggested that the optimal level of CLA in the diet of broiler chickens is 1.0%.更多还原