【作者】 王宇；

【导师】 郑世民；

【作者基本信息】 东北农业大学 ， 基础兽医学， 2010， 硕士

【摘要】 益生素(probiotics)具有维持动物消化道有益菌的优势作用,与有害菌竞争营养物质以维持微生物区系平衡,促进雏鸡免疫器官成熟,增强雏鸡免疫功能,提高抗应激能力,改善肉鸡生产性能。本实验以1日龄肉雏鸡为研究对象,应用分子生物学技术和组织、超微结构检测法,在益生素及其与新城疫(ND)疫苗协同免疫和ND强毒攻击后,对雏鸡生长性能、肉质指标、肌肉肌纤维组织及肌细胞生成素(MyoG)的动态变化进行检测。旨在全面系统的揭示益生素及其与ND疫苗协同免疫和ND强毒攻击后,肉雏鸡生长性能、肉质指标、肌纤维结构和MyoG mRNA表达变化规律。研究结果发现:雏鸡饲喂益生素后7天,其体重明显高于对照雏鸡(p<0.05或p<0.01),且料肉比显著降低(P<0.05),肉质指标明显优于未饲喂益生素的对照雏鸡,表明益生素不但可提高雏鸡生产性能,而且还能改善肉质品质;益生素雏鸡肌肉肌纤维密度和肌纤维脂肪滴含量均较对照雏鸡明显升高,而肌纤维直径较对照雏鸡有所下降,表明雏鸡应用益生素后肌肉肌纤维的生长调节及脂肪组织生成均明显增强;肌肉MyoG mRNA表达于益生素添加后7～14天升高,而后逐渐下降,而益生素雏鸡下降速度慢于对照雏鸡,MyoG mRNA表达与雏鸡营养状况有关。饲喂益生素雏鸡ND疫苗免疫后,其生长性能、肉质指标及肌纤维生长情况均优于未添加益生素雏鸡(p<0.05或p<0.01),ND免疫雏鸡与对照雏鸡无明显差异,表明ND疫苗免疫对雏鸡生长性能和肌肉肌纤维发育影响不明显;益生素雏鸡肌肉MyoG mRNA表达较未添加益生素雏鸡下降缓慢可能与营养代谢相关。ND强毒攻击后,益生素ND免疫雏鸡生长性能、肉质品质均优于单独应用益生素雏鸡和ND免疫雏鸡(p<0.05或p<0.01);肌肉肌纤维生长和MyoG mRNA表达均较对照雏鸡显著提高(p<0.01),表明益生素除具有辅助ND疫苗提高激活机体获得性免疫功能外,还可增强在ND强毒攻击后机体代谢的稳定性,并可提高雏鸡对ND疫苗的免疫应答及降低雏鸡发病率,增强抵抗病毒攻击能力。上述研究结果首次从肌纤维结构和分子水平全面揭示了益生素具有提高雏鸡生产性能,优化肉质品质的作用,为益生素使用和研制提供科学理论依据。更多还原

【Abstract】 Probiotics, in the animal digestive tract, has a dominate role of beneficial bacteria, they can take nutrients competition with harmful bacteria to maintain the balance of microbial flora for mature of chick immune organs, and enhance immune function, improve stress resistance, broiler performance. The experiment was conducted by using of one-day-old chicks. The growth performance, meat quality indicators, muscle fiber structure and MyoG mRNA expression of probiotics-fed chicks, ND-vaccinated and probiotics-fed chicks and following challenged with NDV were examined by molecular biology technology and organization, ultrastructure detection. The results were as follows:Chicks were fed with probiotics an one day age and changes of growth performance and meat quality were studied. The body weight of chicks post fed was significantly higher than in control unfed group chicks, and forage/flesh proportion was lower than them at 7 days later (p<0.05, p<0.01). Meat indicators are much higher than the control chicks unfed, showed that probiotics improve chick performance as soon as meat quality. The muscle density and lipid droplets in muscle fiber of chicks with probiotics was significantly higher than that of control chicks, and muscle fiber diameter decreased compared with control chicks, showed that chicks fed with probiotics regulate the growth of muscle fibers and adipose tissue formation was significantly enhanced. The expression of MyoG mRNA in muscle increased from 7 to 14 day post fed, then gradually decreased, while the slower rate of decline in probiotics-fed chicks were the control chicks, the expression of MyoG mRNA could be with nutritional status of the chicks.ND-vaccinated chicks with probiotics, its growth performance, meat quality and the growth of muscle fibers are better than those without probiotics (p<0.05, p<0.01), ND-vaccinate chicks was no significant difference with control chicks. Account for the above-mentioned examples, it could be show that ND vaccine on chicks growth performance and muscle was no obvious effect on muscle fiber development. The expression of MyoG mRNA of chick with probiotics decrease more slowly without unfed probiotics may be relate to nutrition metabolism.All of the probiotics-fed and ND-vaccinated chicks were successfully protected post challenged with NDV. At the meantime, ND-vaccinated chick with probiotics on growth performance, meat quality is better than alone ND-vaccinated and probiotics-fed chicks. Muscle growth, muscle fibers and MyooG mRNA expression of probiotics-fed chicks increased significantly than control chicks (p<0.01). In addition to a secondary that probiotics enhance the activation of ND vaccine organism acquired immune function, can also enhance the stability of metabolism after virulent attack, chicks of the ND vaccine can enhance the immune response and reduce the incidence of chick, enhanced resistance to virus attack.All of the results suggested that the first time methods of muscle fiber structure detection and molecular technique revealed the probiotics could improve overall production performance and optimize meat quality of chick, a scientific theory is provided for use and development of probiotics.更多还原