重组鸡干扰素-γ对脂多糖引起的肉鸡免疫应激的影响

文章旨在研究前期注射重组鸡干扰素-γ(rChIFN-γ)对肉鸡免疫应激的影响。将40羽14日龄肉鸡随机平均分成A、B、C和D 4组。于14、21、28和35日龄给A组和B组肉鸡静脉注射PBS缓冲液1mL.只-1,C组同期静脉注射含rChIFN-γ50μg的PBS缓冲液1mL.只-1,D组同期静脉注射含rChIFN-γ100μg的PBS缓冲液1mL.只-1。于36、38、40日龄,给B、C、D组的肉鸡腹腔注射含有大肠杆菌脂多糖(LPS,按体质量以250μg.kg-1计算)的PBS缓冲液1mL.只-1造模,A组同期腹腔注射PBS缓冲液1mL。记录36日龄至41日龄肉鸡的体质量和采食量,测定第3次注射脂多糖(40日龄)12h肉鸡的血常规和T淋巴细胞刺激指数,并于第3次注射脂多糖后12、24和36h,测定肉鸡血清白细胞介素-1(IL-1)、皮质酮(CORT)的含量。研究表明:(1)在整个免疫应激时期(36～41日龄),A组的平均日增体质量(P<0.01)和平均日采食量(P<0.05)均要高于B、C、D 3组,A组的料重比要显著低于B、C、D 3组(P<0.05);(2)第3次注射脂多糖后12h,C组和D组的白细胞总数显著高于A组和B组(P<0.05);(3)第3次注射脂多糖后12h,C组和D组的淋巴细胞刺激指数显著高于A组和B组(P<0.05);(4)第3次注射脂多糖后12h,A组的CORT含量显著低于B组(P<0.05),第3次注射脂多糖后24h,A组的CORT含量低于B组(P<0.01)、C组(P<0.05)和D组(P<0.05),第3次注射脂多糖后36h,A组显著低于B组(P<0.05);(5)第3次注射脂多糖12h后,A组IL-1显著低于B组(P<0.05),第3次注射脂多糖24h后,A组极显著低于其它各组(P<0.01)。结果显示,前期注射rChIFN-γ,可以缓解免疫应激导致的肉鸡血清中IL-1和皮质酮升高,提高免疫应激时期肉鸡的细胞免疫功能,缓解免疫应激对肉鸡的负面影响。

Effects of Recombinant Chicken Interferon-γ on Lipopolysaccharide Induced Immunological Stress in Broilers

The objective of this experiment was to research the effects of injection recombinant chicken interferon-γ(rChIFN-γ) in the prophase on immunological stress broilers.Forty 14-day-old healthy AA broilers were allotted to 4 groups randomly which were group A,group B,group C and group D.The broilers of group A and group B were injected with 1 mL PBS at 14,21,28 and 35 days of age.At the same time,the group C was injected with 50 μg rChIFN-γ(in 1 mL PBS) and the group D was injected with 100 μg rChIFN-γ(in 1 mL PBS).At the time of 36-day-old,38-day-old and 40-day-old,the broilers of group B,group C,group D were injected with PBS(1 mL) which contained LPS(250 μg·kg-1 BW).At the same time,the broilers of group A were injected with PBS(1 mL) only.The performance indices were recorded at the time of 36-day-old.Recorded the weight and intake of each broilers from 36 to 41 days.Hematologic indices and T-lymphocytes proliferation of broilers were assayed at 12 hours post the third injection of LPS.The concentration of interleukin-1(IL-1) and corticosterone(CORT) in the serum were measured at 12,24,36 hours post the third injection of LPS.The results showed that:(1) during the challenge,the growth performance was not affected by rChIFN-γ(P>0.05);(2) 12 hours after the third injection of LPS,the white blood cell counts of group C and group D were higher than that of group A(P<0.05) and group B(P<0.05);(3) 12 hours after the third injection of LPS,the T-lymphocyte stimulation index of group C and group D were higher than that of group A and group B(P<0.05);(4) 12 hours after the third injection of LPS,the CORT of group A was lower than that of group B(P<0.05);24 hours after the third injection of LPS,the CORT of group A was lower than that of group B(P<0.01),group C(P<0.05) and group D(P<0.05),36 hours after the third injection of LPS,the CORT of group A was lower than that of group B(P<0.05);(5) 12 hours after the third injection of LPS,the IL-1 of group A was lower than that of group B(P<0.05),24 hours after the third injection of LPS,the group A was lower than that of the other groups(P<0.01).As the results shown,injection of rChIFN-γ at prophase could release the IL-1 and CORT in the immunological stress broilers,improve the cell immunity during the stress.