The Study Of Clinical Efficacy And Safety Of Somatostatin Dna Vaccine Without Antibiotic Resistance Gene Immunized Against Fattening Pigs

Our previous studies have proved that the recombinant bacteria C500(p VGS/2SS-asd) gene vaccine can promote the growth of mice, also no adverse effect on small animals was found. This study was designed in order to investigate the effect of the vaccine on large animals and their mechanism and safety. In this experiment, the total of 78 fattening pigs of equal number of both sexes of 80 days old were used. The fattening pigs were randomly divide into six groups and oral and nasal group was administered with three different doses for processing(5×1011 cfu/head, high),(5×1010 cfu/head, medium),(5×109 cfu/head, low). administered the same dose(5×1011 cfu/head) of vaccine in three different ways:(oral and nasal),(oral), and(nasal) for immune. The trail lasted 90 days. Fattening pigs’ s feed consumption and bodyweight was recorded by automatic WINFIRE measurement swine production performance system(OSBORNE companies in the United States). we evaluate the safety of vaccine by observing whether behaviors and body temperature is normal, using PCR method to detect gene integration and environment diffusion,after immunization; Antibodies and hormone levels were determined using immunoassay techniques. 1. The growth performance and feed conversation ratioAccording to the dates from automatic WINFIRE measurement swine production performance system.We found that the early and later stage of immune fattening pigs growth speed was faster and slow, respectively. In order to explore the effects of immune manners on growth-promoting of fattening pigs,Compared to control group each period,the average daily body weight gain of various immune group were higher. After immunized 4-7 weeks.The average daily body gain of nasal group were higher(p<0.05) than control group; In order to explore the effects of immune dose on growth-promoting of fattening pigs. According to the results. In 7 weeks after immunization, the combination immunity manner(oral + nasal immune), mid dose, low dose groups of daily body gain was both increased by 19.94% as compared to control groups, and significant was observed(P<0.01) across the whole trial. The combination oral + nasal immunity low dose group daily body weight gain was significantly higher(P<0.05) compared to control group and was increased by 9.41%.Average daily feed intake of immune manner groups and,immune dose groups was slightly higher(P>0.05) compared control group, but feed conversion ratio did not vary(P>0.05). 2. SafetyIn this study, the daily behaviors, gene integration, environmental contamination after immunization was used to evaluate the safty of the the recombinant bacteria C500(p VGS/2SS-asd) gene vaccine. we found all pigs showed normal food, drinking water, mental state, other daily behavior, and temperature were normal; we collected every pig’s heart, liver, lung, muscle, adipose tissue when the fattening pigs slaughter, and extracted DNA and detected by PCR. All organizations were not detected in the GS/2SS gene. The plasmid was not integrated into animal genome; after immunization of 1、3、5、7、10、15、20、30 days to collect all the test samples. Samples of fattening pigs dung, water,5 meter soil before and after the fat gery, after PCR detection, we found no suspicious colony amplification of GS/2SS gene. From this present study, it can be said that somatostatin DNA gene vaccine is harmless to the environment or don’t contribute to the environmental pollution. 3. Effect of immune responseAccording to the results of three kinds of immune way are successfully induced the body’s immune response, Antibodies of oral + nasal group and oral group were significantly higher(P<0.05) than control group, and oral + nasal group significantly higher than oral group. Fattening pigs of low dose group embody the better(P<0.05) immune effect. The antibody level of low dose was significantly higher(P<0.05) compared to the control group, growth hormone levels were higher than the control group, but significant difference did not observed(P>0.05).