规模化养殖场肉鸡腿病情况调查及bFGF在肉鸡股骨头坏死发生中的作用机理研究

发布时间：2018-09-08 20:25

【摘要】：随着肉鸡养殖规模化和集约化的发展,肉鸡的生产性能得到显著提升的同时,肉鸡腿病发生率在我国呈显著上升的趋势,严重影响了肉鸡养殖的经济效益和动物福利。肉鸡腿病种类众多,常见的包括胫骨发育不良(Tibialdyschondroplasia,TD),股骨头坏死(femoralheadnecrosis,FHN),佝偻病(Rickets)等。而在众多腿病中,股骨头坏死常导致患鸡跛行而不能正常饮水和采食,影响尤为重大。股骨头坏死发生机理比较复杂,目前尚无定论,由于干骺端软骨细胞的凋亡会影响股骨头血液灌流,从而导致股骨头因缺乏营养供应而坏死,因此本试验从细胞凋亡的角度出发尝试探讨该病可能的发生机理。碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)在成骨细胞内合成并储存,它对骨细胞的前期增殖发挥有效的刺激作用的同时也对软骨细胞有着抗凋亡的作用。目前有关bFGF对骨细胞凋亡以及进而导致肉鸡FHN发生的报道鲜有所见。本研究的目的在于对我国规模化肉鸡养殖场肉鸡腿病的发生情况进行调查,同时对在肉鸡FHN发生中bFGF的作用及其对肉鸡软骨细胞凋亡的影响进行了探讨。1、规模养殖场肉鸡腿病情况调查对安徽省某集团公司9个肉鸡养殖场进行肉鸡腿病流行病学调查,并根据已有的肉鸡步态评分方法对发病肉鸡进行步态评分;然后,随机选取10只发病肉鸡进行扑杀,并在每个养殖场取10只正常肉鸡作对照,对扑杀的肉鸡进行病理剖检和骨组织采样,取病料进行微生物学检测和病理组织学观察;最后,结合各种诊断结果对样品中每只肉鸡腿病的类型作出诊断,并对所有的腿病进行分类、统计和分析。结果:肉鸡腿病发病率为2.07%,症状轻微的肉鸡占发病鸡总量的50.92%,有明显跛行的肉鸡占发病鸡总量的20.66%,丧失行走能力的占28.42%。实验室诊断发现,导致肉鸡跛行的主要病因是细菌感染,占发病鸡总量的36.67%;在非细菌感染病例中,TD占发病鸡比重最高,达到34.44%,而FHN占发病鸡总量的13.33%;此外,外伤骨折和部分未知原因发生腿病的肉鸡分别占发病鸡总量的6.67%和8.89%。2、bFGF在自然发病肉鸡股骨头坏死中的作用机理研究选取100只健康的1日龄Ross308白羽肉鸡为试验动物,自由采食饲养,42日龄后将所有的鸡称重并处死。通过剖检观察股骨头完整性以及股骨生长板形态变化并进行FHN评分,并分别对肝指数、软骨细胞细胞凋亡数量、bFGF和凋亡相关基因的表达、骨长、骨指数、骨强度、骨密度和骨灰分进行测定。结果发现,FHN发病率为20.9%;肉鸡在体重、肝指数、骨长、骨重、骨强度和骨密度上差异不显著,FHN肉鸡胫骨灰分重占干重比明显低于未发生腿病肉鸡,股骨头软骨细胞脂肪空泡数量和凋亡数量都明显高于未发生腿病肉鸡,但静止区软骨细胞数量上,未发生腿病肉鸡与FHN差异不显著;FHN肉鸡股骨头生长板bFGF蛋白表达量明显低于未发生腿病肉鸡,Bax和caspases-3的RNA表达量显著升高,bFGF和Bcl-2 RNA表达量显著降低。上述结果表明,生长板软骨细胞凋亡在肉鸡FHN发生的过程中扮演着重要的角色,而bFGF通过调节凋亡相关基因的表达介导软骨细胞凋亡并进而影响着肉鸡FHN的发生。
[Abstract]:With the development of large-scale and intensive broiler breeding, the production performance of broilers has been significantly improved. At the same time, the incidence of broiler leg disease in China is increasing significantly, seriously affecting the economic benefits and animal welfare of broiler breeding. Femoral head necrosis (FHN), rickets and so on. In many leg diseases, femoral head necrosis often leads to lameness of chickens and can not normally drink and eat, the impact is particularly significant. In this study, we attempted to explore the possible mechanism of osteoporosis from the point of view of cell apoptosis. Basic fibroblast growth factor (bFGF) is synthesized and stored in osteoblasts, which plays an effective role in stimulating the early proliferation of osteoblasts. The purpose of this study is to investigate the occurrence of broiler leg disease in large-scale broiler farms in China, and to investigate the role of bFGF in the development of broiler FHN and its effect on broiler softness. The effect of osteocyte apoptosis was discussed. 1. Investigation of broiler leg disease in large-scale farms carried out epidemiological investigation of broiler leg disease in 9 broiler farms of a group company in Anhui Province. Gait score was made according to the existing gait score method of broiler chickens. Then, 10 broiler chickens were randomly selected for culling, and each chicken was culled. Ten normal broilers were selected as control, and the culled broilers were examined by pathological dissection and bone tissue sampling, and the pathogenic materials were examined by microbiology and pathological histology. Finally, the types of leg diseases in each broiler were diagnosed according to various diagnostic results, and all leg diseases were classified, statistically analyzed. The incidence of leg disease was 2.07%. The mild symptoms of broilers accounted for 50.92% of the total chickens. The obvious lameness of broilers accounted for 20.66% of the total chickens. The loss of walking ability accounted for 28.42%. The highest proportion of chickens was 34.44%, while FHN accounted for 13.33% of the total chickens. In addition, 6.67% and 8.89% of the total chickens suffered from traumatic fracture and some unknown leg disease respectively. 2. The mechanism of bFGF in the necrosis of femoral head in naturally occurring broilers. 100 healthy 1-day-old Ross 308 white-feathered broilers were selected as experimental animals. After feeding, all chickens were weighed and killed at 42 days of age. The integrity of femoral head and morphological changes of femoral growth plate were observed by dissection and FHN score was performed. The liver index, the number of chondrocyte apoptosis, the expression of bFGF and apoptosis-related genes, bone length, bone index, bone strength, bone density and bone ash were measured. The results showed that the incidence of FHN was 20.9%. There was no significant difference in body weight, liver index, bone length, bone weight, bone strength and bone mineral density among broilers. The expression of bFGF protein in the growth plate of the femoral head of FHN broilers was significantly lower than that of the broilers without leg disease. The expression of Bax and caspases-3 RNA was significantly increased, while the expression of bFGF and Bcl-2 RNA was significantly decreased. BFGF plays an important role in inducing chondrocyte apoptosis by regulating the expression of apoptosis-related genes, which in turn affects the occurrence of FHN in broilers.
【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S858.31

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