Effect And Breed Differences As Well As Safety Of Somatostatin Genetic Immunization In Beef Cattle

In this research, a series of techniques were used such as bacterial culture and fermentation vaccine, ELISA, RIA. We use pVGS/2SS-asd DNA vaccine intranasal immune 40 young bulls aged 2-3 years, The DNA vaccine which was a previously constructed against somatostatin (SS) in our laboratory. The objective is studying effects of growth and safety about somatostatin gene immune on beef cattle. This study can afford a novel method to improve growth function of beef cattle.1. Expression of antibody level in young bull’s blood plasma after somatostatin genetic immunizationA total of 40 beef cattle,19 in indigenous breed at age of 2 years old and 21 in crossbreed (Simmental x indigenous breed) at age of 1 years old were random divided into 2 groups for each breed. Animals in the test groups (n=5 for each) were give a nasal immunization of somatostatin genetic vaccine in doses of 5×1010CFU/ml,5×109CFU/ml, 5x108CFU/ml and 0 in PBS as a control (n=5). After the first immunization, all animals in test groups were given 2 booster immunizations in dose as same as the first immunization at interval 3 and 9 weeks respectively. The results about antibody assaies suggested that all dose groups can make tested-cattle response to the immunization. After the first three weeks of the immunization, high dose induced higher antibody levels, which suggested the antibody level is dose-dependence. But low dose induce higher antibody levels in crossbreed, which indicted that the level production was related to animal breed.2 Effect of pVGS/2SS -asd on daily gain of young bullsAfter the first booster immunization 2 weeks,5 weeks and 9 weeks, The daily gain was better than control in indigenous breed. After booster immunization 2 weeks, the daily gain of high dose group was significantly higher than control (p<0.05). After booster immunization 5 weeks and 9 weeks, the daily gain of high-dose group and middle-dose group were significantly higher than the control (p<0.05). Compared with the crossbreed, after the first immunization and the first booster immunization, the daily gain level are better than control with insignificant in the low-dose group (p>0.05).As improved the beef cattle nutrient in the later stage, the daily gain of all cattle were significantly improved after the second booster immunization. After booster immunization 4 and 8 weeks, the daily gain of crossbreed are higher than control with insignificant (p>0.05).3 Effect of pVGS/2SS -asd on hormone secretion level of young bullsThree weeks after first immunization, compared with the pre-immune serum growth hormone levels, its secretion level raised. Five weeks after the immunization, the growth hormone levels of the local cattle high-dose group were significantly decreased compared with other treated group (p<0.05). After nine weeks strengthened immunity, the GH levels were higher than control (p<0.05) in indigenous. After booster immunization nine weeks, the hormone levels were significantly higher than control (p<0.05) in crossbreed.4 Effects of pVGS/2SS-asd on safety of young bullsIn order to estimate the safety of young bull after vaccine immunized, this study include clinical manifestation, temperature, heart rate, blood and so on. The result indicate that there are any abnormal after cattle immunization on eating, drinking, lively and excrement, after 1d,2d,3d,4d and 5d immunization, Compared with control, the body temperature and heart rate of treated groups were swayed within the normal range with no significantly differences between indigenous and crossbreed (p>0.05).After 3 and 5 weeks immunization, different doses of the vaccine showed no significant difference on index of blood (WBC, RBC, HGB, HCT, MCV, MCH, MCHC, RDW) among each groups (p>0.05). which indicted that gene vaccine are safety to the cattle.