【作者】 张凯；

【导师】 吴艳涛； 施静；

【作者基本信息】 扬州大学 ， 兽医硕士（专业学位）， 2021， 硕士

【摘要】 黑羽番鸭羽色特异、肉质好、有特殊的经济价值,备受消费者和养殖户的青睐,为了最大程度地满足黑羽番鸭集约化饲养条件下对营养物质的需要,提高饲料利用率,本研究比较了不同代谢能、蛋白质、钙和有效磷水平日粮对黑羽番鸭生长性能、血液生化指标和抗病力的影响,旨在为科学养殖黑羽番鸭提供依据。本研究通过资源配方师Refs3000系列软件,在1～21日龄,22～42日龄,43～91日龄三个生长阶段,各设计9种饲粮配方(A1-A9,B1-B9,C1-C9)。选用864羽1日龄的黑羽番鸭,采用4因素3水平L9(34)正交试验,测定试验鸭的生长性能、血液生化指标和营养物质表观消化率。采用实时荧光定量PCR检测不同组织中的生长激素(Growth hormone,GH)和生长激素受体(growth hormone receptor,GHR)基因的mRNA表达的差异。本研究还通过测定免疫器官的重量和禽流感灭活疫苗免疫后的抗体水平,评价不同日粮营养水平对黑羽番鸭抗病力的影响。A3组试验鸭表现出了最高的生产性能,其平均日增质量、血清总蛋白、白蛋白和球蛋白水平显著高于其他组,因此1～21日龄的营养需要量为A3:11.72 MJ/KG,20.49%、1.05%、0.6%和0.71%。B3组试验鸭料重比低,屠宰率、血清中总蛋白、白蛋白和低密度脂蛋白最高,因此22～42日龄的营养需要量为B3:11.92MJ/KG、19.25%、1.03%、0.60%和0.73%。C2组试验鸭胸肌率、腿肌率较多,pH最高,因此43～91日龄的营养需要量为C2:12.32MJ/KG、16.10%、0.92%、0.45%和0.68%。在番鸭早期生长发育过程中,GH、GHR基因mRNA水平无差异。91日龄时腿肌GH基因表达因日粮营养水平不同而显示出差异性,其中C6组腿肌中GH基因表达量显著高于C5组(P<0.05),而在胸肌未表现出明显差异。C3组胸肌中GHR基因表达量显著高于C4和C8组,C6组腿肌中GHR基因表达量显著高于C1、C7、C8和C9组(P<0.05)。由于日粮中不同粗蛋白、代谢能、钙和有效磷配比,尤其是粗蛋白含量对GH、GHR基因在胸、腿肌中表达时起到了促进的作用。不同营养水平日粮对黑羽番鸭抗病力影响显著。在21日龄、42日龄和91日龄,2组和3组黑羽番鸭的胸腺、法氏囊、脾脏器官指数均显著高于其他组(P<0.01),尤其是3组黑羽番鸭的免疫器官指数最高。9组免疫器官生长较慢,21日龄和42日龄时,胸腺、法氏囊、脾脏器官指数显著低于其他组,但是在91日龄时各组差异不显著。表明最佳营养水平的日粮能够提高机体生长性能,并促进机体免疫器官发育。进一步检测H5亚型禽流感灭活疫苗后的抗体水平,结果表明,1组一免后抗体效价为2.8log2,二免后抗体效价为4.47log2,与4、5、6、7和8组均差异不显著。2和3组一免后抗体效价分别为3.67 log2和3.58 log2,二免后抗体效价分别达到5.17 log2和5.11 log2,显著高于其他组(P<0.05)。而9组一免后抗体效价2.64log2,二免后抗体效价为3.89log2,显著低于其他组。表明,最佳日粮水平3组能够促进机体疫苗免疫后免疫应答,提高机体免疫力。本次试验通过全程监测黑羽番鸭的生长性能,确定了在不用生长阶段黑羽番鸭的最佳日粮水平。通过改善试验鸭的生长性能,可以促进番鸭免疫器官的成熟,增强番鸭的免疫器官发育,提高自身免疫性能,从而提高了黑羽番鸭的经济效益。更多还原

【Abstract】 In my country,black feathered muscovy duck has special color,good meat quality and special economic value,which is favored by consumers and farmers.In order to meet the needs of nutrients for black feather muscovy duck under intensive feeding conditions and improve feed utilization rate,this study compared the effects of diets with different levels of metabolizable energy,protein,calcium and available phosphorus on growth performance,blood biochemical indexes and anti-bacterial activity of black feather muscovy duck In order to provide scientific basis for breeding black muscovy duck.In this study,nine diets(A 1-A9,B1-B9,C1-C9)were designed in three growth stages of 1-21 days old,22-42 days old and 43-91 days old by refs3000 software.864 1-day-old black Muscovy ducks were selected.The growth performance,blood biochemical indexes and apparent digestibility of nutrients were determined by L9(34)orthogonal test with 4 factors and 3 levels.The mRNA expressions of growth hormone(GH)and growth hormone receptor(GHR)in different tissues were detected by real-time PCR.The weight of immune organs and the antibody level of inactivated avian influenza vaccine were measured to evaluate the effect of different dietary nutrition levels on the disease resistance of black Muscovy ducks.The results showed that the average daily gain,serum total protein,albumin and globulin levels of group A3 were significantly higher than those of other groups.Therefore,the nutritional requirements of group A3 were 11.72mj/kg,20.49%,1.05%,0.6%and 0.17%.In group B3,the feed to weight ratio was low,the slaughter rate,serum total protein,albumin and low density lipoprotein were the highest,so the nutritional requirements of 22-42 days old ducks were B3:11.92 MJ/kg,19.25%,1.03%,0.60%and 0.73%.In C2 group,the breast muscle rate and leg muscle rate were more,and the pH was the highest.Therefore,the nutritional requirements of 43-91 days old ducks were C2:12.32mj/kg,16.10%,0.92%,0.45%and 0.68%.There was no difference in the mRNA levels of GH and GHR genes during the early growth and development of Muscovy ducks.The expression of GH gene in leg muscle of C6 group was significantly higher than that of C5 group(P<0.05),but there was no significant difference in chest muscle.The expression of GHR gene in chest muscle of C3 group was significantly higher than that of C4 and C8 groups,and the expression of GHR gene in leg muscle of C6 group was significantly higher than that of C1,C7,C8 and C9 groups(P<0.05).Due to the different ratio of crude protein,metabolizable energy,calcium and available phosphorus,especially crude protein content,GH and GHR gene expression in chest and leg muscles were promoted.The effect of different nutrition levels on disease resistance of black feathered muscovy duck was significant.At 21,42 and 91 days of age,the indexes of thymus,bursa of Fabricius and spleen in groups 2 and 3 were significantly higher than those in other groups(P<0.01),especially in group 3.The growth of immune organs in 9 group was slow.The organ indexes of thymus,bursa of Fabricius and spleen in 21 and 42 days old were significantly lower than those in other groups,but there was no significant difference in 91 days old.The results showed that the best nutrition level could improve the growth performance and promote the development of immune organs.The results showed that the antibody titer of 1 group was 2.8log2 after the first immunization and 4.47log2 after the second immunization,and there was no significant difference between 1 group and 4,5,6,7 and 8 groups.The antibody titers of 2 and 3 groups were 3.671og2 and 3.58 log2 respectively after the first immunization,and 5.17 log2 and 5.11 log2 respectively after the second immunization,which were significantly higher than those of other groups(P<0.05).The antibody titer of 9 group was 2.64 log2 after the first immunization and 3.89 log2 after the second immunization,which was significantly lower than that of other groups.The results showed that the optimal dietary level 3 could promote the immune response and enhance the immunity of the body.In this experiment,the growth performance of black feathered muscovy duck was monitored in the whole process,and the best dietary level of black feathered muscovy duck was determined in the non growth stage.By improving the growth performance of the experimental ducks,it can promote the maturity of the immune organs of Muscovy ducks,enhance the development of the immune organs of Muscovy ducks,and improve the autoimmune performance,so as to improve the economic benefits of black Muscovy ducks.更多还原