In poultry production, vaccination is an effective measure to protect chickens from diseases. Vaccination, however, is a stressor that may induce stress responses that interfere with the growth and development of chickens. The interaction between the skeletal and immune systems on bone quality has gained more attention. In the present study, the influence of high frequency vaccinations on the bone development of layer pullets was investigated. Thirty 35-day-old SPF White Leghorn layer pullets were obtained and randomly subjected to the following treatments: vaccinated against Newcastle disease (ND) with LoSota vaccine once at 35-day-old (V1, control); 4 times at 35, 49, 63, and 77 d of age (V4); and 7 times at 35, 42, 49, 56, 63, 70, and 77 d of age (V7). The body weight and organ index of the spleen, thymus, and tibia were recorded. The antibody titer and serum and the tibia calcium and phosphorus concentrations were measured. The transcription levels of the IL-6, IL-17, TNF-α, receptor activator of NF-κB ligand (RANKL), and osteoprotegerin (OPG) genes were determined in spleen, thymus, and the tibia. The results showed that V7 decreased body weight and increased the ND antibody titer, compared to V1-chickens. The expression levels of IL-6, IL-17, and TNF-α were upregulated in spleen, thymus, and the tibia of V7 chickens. In the tibia, RANKL was upregulated, while OPG was downregulated by V7 treatment. The results indicate that high frequency vaccination induces immune stress and impairs bone development. The results suggest that the augmented cytokine expression in immune organs and the tibia is associated with activation of the OPG/RANKL pathway, which, in turn, enhances osteoclastogenesis. The appropriate frequency of vaccination should support optimal bone development and full immunoprotection in layer pullets.

中文翻译：

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高频疫苗诱导的免疫应激会伴随着层状ets的活化破骨细胞生成而降低骨骼强度。

在家禽生产中，接种疫苗是保护鸡免受疾病侵害的有效措施。但是，疫苗接种是一种应激物，可能引起应激反应，从而干扰鸡的生长和发育。骨骼和免疫系统之间对骨骼质量的相互作用已引起更多关注。在本研究中，研究了高频疫苗接种对蛋鸡的骨骼发育的影响。获得三十只35天大的SPF白来亨鸡层小母鸡，并随机进行以下处理：在35天大的时候，用LoSota疫苗接种新城疫（ND）疫苗（V1，对照）；在35、49、63和77 d年龄（V4）拍摄4次；和分别在35、42、49、56、63、70和77 d（V7）年龄7次。记录脾脏，胸腺和胫骨的体重和器官指数。测量抗体滴度和血清以及胫骨钙和磷的浓度。确定了脾脏，胸腺和胫骨中IL-6，IL-17，TNF-α，NF-κB配体的受体激活剂（RANKL）和骨保护素（OPG）基因的转录水平。结果表明，与V1鸡相比，V7减轻了体重，增加了ND抗体效价。V7鸡的脾脏，胸腺和胫骨中IL-6，IL-17和TNF-α的表达水平上调。在胫骨中，通过V7处理，RANKL上调，而OPG下调。结果表明，高频疫苗接种可诱发免疫应激并损害骨骼发育。结果表明，免疫器官和胫骨中细胞因子的表达增加与OPG / RANKL途径的激活有关，而OPG / RANKL途径的激活又与 增强破骨细胞生成。适当的疫苗接种频率应支持最佳的骨骼发育和蛋鸡的完全免疫保护。