Study On Application And Mechanism Of Various Combinative Antibiotics In 7～35d Sucking Piglets

The experiment was designed to study growth-promoting Mechanism of antibiotics and effects of combinative antibiotics on production performance, intestinal flora, blood biochemical indexes and apparent digestibility in sucking piglets at the age of 7 days. Twenty litters of piglets were assigned to five groups randomly, with four litters per group. The five treatments were the oxytetracycline+avilamycin group, the chlortetracycline+flavomycinwa group, the oxytetracycline+flavomycinwa group, the olaquindox+flavomycinwas and the sulfadiazine+trimethoprim respectively, the basic diet of the five group was same.The experiment experienced 28 days. One piglet of each replicate was collected fresh dejecta on 21 and 35-day–old respectively to measure intestinal flora. And one piglets of each replicate were selected to take blood in order to measuring the blood biochemical indexes at the same time. During the 33~35day, one piglet of each replicate was selected to conduct the apparent digestibility of nutrients.1. The effect of combinative antibiotics on production performance in sucking pigletsThe diet containing olaquindox+flavomycinwas reduced diarrhea frequency significantly (P<0.05) during the first the secent and the whole stage, which had better control on diarrhea frequency than the other groups. And the oxytetracycline+flavomycinwa group improved the average dailly weight gain significantly(P<0.05) over the second phase and the whole phase.2. The effect of combinative antibiotics on microflora populationThe experiment results showed that antibiotics had effect of the large intestinal microflora population. On the 21-day-old, The E.coli concentration of the sulfadiazine+trimethoprim group was lower(P<0.05) than that of the chlortetracycline+flavomycin group. And the sulfadiazine+trimethoprim group decreased the E.coli concentration at 4.9%, 5.3%, 9.8% comparing with the olaquindox+flavomycinwas group, the oxytetracycline+flavomycinwa group, the oxytetracycline+avilamycin group; The olaquindox+flavomycinwas group had higher the Lactoacilli concentration than the sulfadiazine+trimethoprim group. On the 35-day-old, E.coli concentration of the sulfadiazine+trimethoprim group was significantly lower(P<0.05), but there is no difference between sulfadiazine+trimethoprim group and the olaquindox+flavomycinwas group; The Lactoacilli concentration of the olaquindox+ flavomycinwas group, the oxytetracycline+flavomycinwa group, the oxytetracycline+ avilamycin group was higher(P<0.05) than the sulfadiazine+trimethoprim group.3. The effect of combinative antibiotics on blood biochemical indexes, endocrine and immune globulinOn the 21-day- old, the blood glucose level of the oxytetracycline+flavomycinwa was sinigfcantly higher (P<0.05),at the age of 35 days, the oxytetracycline+flavomycinwa group improved the serum glucose (P<0.05). On the 21th day, the oxytetracycline+flavomycinwa group improved the total cholesterol and triglyceride(P<0.05), and at 35 days of age, the oxytetracycline+flavomycinwa group had higher total cholesterol and triglyceride than that of the 21 days, meanwhile, the two indexes didn't affected by treatments. On the 35th day, the level of serum urea nitrogen was lower(P<0.05) than that of all treatments of 21days, and the oxytetracycline+flavomycinwa group decreased significantly(P<0.05) the level of serum urea. There was no significant difference in glutamic-pyruvic transaminase amony the oxytetracycline+flavomycinwa group, thes ulfadiazine+trimethoprim group, and the chlortetracycline+flavomycin group on the 21th day, which had higher glutamic-pyruvic transaminase than the other two groups; at 35 days of age, the oxytetracycline+flavomycinwa group significantly improved the glutamic-pyruvic transaminase (P<0.05). On the 21, 35-day-old, the level of glutamic-oxaloacetic transaminase of the oxytetracycline+ Flavomycinwa group was significantly higher (P<0.05) than the other groups, but no significant diference was occurred between 21days and 35 days of the same treatment. For the piglets fed a diet supplemented with ciombinative antibiotics, the levels of T3, insulin and serum growth hormone of the oxytetracycline+Flavomycinwa group increased significantly(P<0.05), but there was no significant difference in T4 level amony all the treatments.No difference for immune globulin (IgG, IgM, IgA ) was found amony the all treatments. 4. The effect of combinative antibiotics on nutrient digestibilityThe oxytetracycline+Flavomycinwa group increased the apparent digestibility of CP, GE and DM (P<0.05), and the effect of its is better.