The Effects Of Organic Selenium And Bacillus Subtilis On Production Performance And Gene Expression Of Rabbits

Three hundred and sixty New Zealand white rabbits weaned at 30th day were randomly divided into 6 groups by weight, such as control group, Selenium yeast group(0.4mg/kg Selenium Content),Selenium methionine group(0.4mg/kg Selenium Content),0.4% Bacillus subtilis group, Mixed group1 and Mixed group2. Each group has three repeats, twenty replicates per group. This test lasted 60 days. This experiment was conducted to investigate the effects of diet supplementation with organic yeast and Bacillus subtilis on organism production performance and anti-oxidation performance. Internal mechanism of action was investigated by using molecular biology methods. Study included three parts of experiments.Experiment 1 Effects of organic selenium and Bacillus subtilis on growth performance of rabbitsFeed intake was recorded every day, since from 30 days, every 10 days weighed one time, calculated daily gain, daily feed intake and feed conversion. After the test, 12 rabbits from each group were slaughtered and the meat rate and slaughter rate were calculated; the liver and breast muscle as samples measured tissue selenium content in the control group, selenium yeast group and the selenium methionine group. The results showed that compared with the control group, ADG(30d) increased greatly significant in Se-yeast group (P<0.01), after the difference was not significant (P>0.05), ADG increased greatly significant in Se-Met and Mixed group2 (P<0.01), ADG increased significant in Mixed group1 (P<0.05); ADFI increased greatly significant in Se-yeast,Mixed group1 and Mixed group2 (P<0.01), but the difference was no significant on 60 day (P>0.05); Feed conversion ratio increased significant in Se-Met and Mixed group2 (P<0.05).On tissue selenium content, liver and meat selenium content in Se-yeast increased significant compared with control group (P<0.05); the slaughter rate in Bacillus subtilis and Mixed group1 increased greatly significant compared with control group (P<0.01), the slaughter rate in Se-yeast increased significant compared with control group (P<0.05), the meat rate in Bacillus subtilis increased significant compared with control group (P<0.05).Experiment 2 Effects of organic selenium and Bacillus subtilis on Anti-oxidation levels of rabbitsIn the feeding experiment of 30 days, 40 days, 50 days and 60 days, 12 rabbits from each group were blooded from ear vein, centrifugation and separation of serum to determinate the serum activity of T-AOC, MDA, SOD and GSH-Px. The results showed that compared with control group,serum T-AOC activities increased significant in Se-yeast group (P<0.05), in later stage, the difference was not significant (P>0.05), serum T-AOC activities increased significant in Se-Met and Mixed group1(P<0.05), serum T-AOC activities(50d and 60d) increased greatly significant in Bacillus subtilis (P<0.01), but the difference was not significant in early stage(P>0.05), serum T-AOC activities(40d and 60d) increased greatly significant in Mixed group2(P<0.01), in the other days, the difference was not significant(P>0.05).On the index of MDA: compared with the control group, in 30 days, serum MDA activity in each experimental group was not significant(P>0.05); in 40 days, serum MDA activity decreased greatly significant in Bacillus subtilis(P<0.01), serum MDA activity decreased significant in Se-Met and Mixed group2(P<0.05); in 50 days, serum MDA activity in each experimental group was not significant(P>0.05); in 60 days, serum MDA activity decreased significant in Se-yeast and Mixed group1(P<0.05), serum MDA activity decreased greatly significant in Bacillus subtilis,Se-Met and Mixed group2(P<0.01).On the index of SOD: compared with the control group, in 30 days, serum SOD activity increased greatly significant in Se-yeast and Bacillus subtilis(P<0.01); in 40 days, serum SOD activity increased significant in Mixed group1(P<0.05); in 50 days and 60 days, the serum SOD activity increased greatly significant in each experimental group(P<0.01).On the index of GSH-Px: compared with the control group, in 40 days, serum GSH-Px activity increased greatly significant in Se-Met, Mixed group1 and Mixed group2(P<0.01); in 50 days, serum GSH-Px activity increased greatly significant in Se-yeast,Se-Met,Mixed group1 and Mixed group2(P<0.01); in 60 days, serum GSH-Px activity increased greatly significant in Se-yeast, Bacillus subtilis and Mixed group2(P<0.01), serum GSH-Px activity increased significantly in Se-Met group(P<0.01).Experiment 3 Effects of organic selenium and Bacillus subtilis on GPX1 and IL-6 gene expression of rabbitsAt the end of the trial, 12 rabbits in each group were slaughtered, whichever leg as the sample was extracted leg muscle RNA, using RT-PCR to study semi-quantitative of GPX1 and IL-6 gene in rabbits. The results showed that compared with the control group, GPX1mRNA abundance increased greatly significant in Se-yeast group, Se-Met group, Mixed group1 and Mixed group2(P<0.01); IL-6mRNA abundance increased greatly significant in Bacillus subtilis group , Mixed group1 and Mixed group2(P<0.01).In general, adding organic selenium and Bacillus subtilis to the diet could improve the production performance, anti-oxidation ability and gene expression level of rabbits, and the effect of organic selenium was better than that of Bacillus subtilis, the effect of selenium methionine was superior to selenium yeast; and organic selenium and Bacillus subtilis also has the synergistic effect, so the overall effect of selenium methionine combination of Bacillus subtilis is the best.