China Animal Husbandry and Veterinary Medicine ›› 2020, Vol. 47 ›› Issue (12): 4041-4050.doi: 10.16431/j.cnki.1671-7236.2020.12.028

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Study on the Growth Promoting Effect of Crossbred Buffalo Calves Immunized with DNA Vaccine of Co-expression of Somatostatin and Cortistatin

YANG Shuai, HU Xiangwei, ZHOU Di, ZHANG Xinxin, YANG Liguo   

  1. College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
  • Received:2020-06-15 Online:2020-12-20 Published:2020-12-18

Abstract: The purpose of this study was to investigate the growth promoting effect and the safety of the vaccine in crossbred buffalo calves immunized with somatostatin and corticostatin co-expression DNA vaccine.The identified plasmid of pVGS/2SS-2A-S/CST-asd was electroporated into attenuated Salmonella Choleraesuis C500 to construct the co-expression live vector vaccine of somatostatin and corticostatin,and evaluate the effect on the growth performance of the crossbreds buffalo after nasal immunization.Twenty four 2-6 months of age crossbred buffalo calves with similar body weight were randomly divided into 4 groups immunized with the vaccine in low dosage group (TL),middle dosage group (TM),high dosage group (TH) and negative control group (NC).Immunization was performed once a day for 3 consecutive days,and a booster was given 2 weeks late.The results showed that the antibody of SS and CST could be produced on 2 weeks after the primary immunization,and TL group was the best,showing higher antibody level and positive rate.At 7 weeks,the positive rate of experimental group showed a downward trend.The daily gain of each experimental group was higher than that of control group at 2 and 7 weeks after the primary immunization,but there was no significant difference between experimental groups (P>0.05),while the average daily gain of antibody positive group (P) was significantly higher than that of negative group (N) at 2 weeks (P<0.05).The results of related hormones showed that the levels of growth hormone (GH) and insulin growth factor 1 (IGF-1) were higher in experimental groups at 2 and 7 weeks after the primary immunization.In each experimental group,TL group showed the best performance,both extremely significantly higher than that of control group except GH level at 7 weeks after the primary immunization (P<0.01),antibody positive group was also significantly higher than negative group (P<0.05).Cytokine test results showed that the interleukin 4 (IL-4) level in experimental groups at 2 weeks after the primary immunization was higher than that of control group,and the IL-4 level in TL and TM groups was extremely significantly higher than that of control group (P<0.01),especially in TL group.The IL-4 level in TL and TH groups at 7 weeks after the primary immunization was significantly higher than that of control group (P<0.05).At 2 weeks after the primary immunization,the level of immune interferon γ (INF-γ) in control group was extremely significantly higher than that of experimental groups (P<0.01),but at 7 weeks after immunization was significantly lower than that of TL and TH groups (P<0.05).The levels of IL-4 and INF-γ in antibody positive group were significantly higher than that of negative group at 2 and 7 weeks after the primary immunization (P<0.05),respectively,and there was no significant difference among other groups (P>0.05).The levels of blood glucose (GLU),total protein (TP),total cholesterol (CH) and urea nitrogen (BUN) in serum showed that except that the level of total protein in TL group at 2 weeks after the primary immunization was significantly higher than that of control group (P<0.05),there was no significant difference of other indexes among each group (P>0.05).In order to confirm the safety of the vaccine,the genes of water,soil and fecal samples after immunization were amplified,which were not detected in PCR sensitivity range.The results indicated that the vaccine could achieve a good immune effect,make the body produce a significant immune response,and the effect of the low dosage group was the best.The vaccine did not cause adverse effects on the environment.

Key words: somatostatin; cortistatin; gene immunity; buffalo calves; growth performance; safety

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