Effect Of Bacillus Subtilis J-4on Broilers’ Production Performance

As a new type of feed additives, feeding probiotics had functions of maintaining theanimal intestinal flora balance, inhibiting the intestinal pathogenic bacteria breeding,avoiding the pathogen resistance in the course of prevention and treatment of diarrhea, andhas incomparable advantages of antibiotics. Forage bacillus preparation as a new type ofprobiotics, not only had the above function, and had the advantages of strong resistance,high temperature resistant, resistant to acid and alkali. In the animal gut, a variety ofdigestive enzymes such as protease, amylase, cellulose enzyme were produced to help theanimals breaking down digest nutrients, improving the feed conversion rate and reducingthe production cost.Bacillus subtilis J-4, which we used as probiotics, was screening from health poultryintestinal by our laboratory which has the function of producing digestive enzymes such asprotease, cellulase lipase, amylase enzymes and has significant inhibitory effect on thepoultry intestinal common pathogenic bacteria such as E.coli.Growth performance, digestive performance and influence of the intestinal microbialflora of feeding Bacillus subtilis J-4preparation to broilers were studied by allotting30004-day-old broilers to the test group and the control group randomly.0.1%J-4agent (livingbacterium content1.0x1010cfu/g) was added to the test group from1-day to18-day,compared with feeding basal diet to the control group. Weight gain, feed conversion ratio,diarrhea rate, mortality, digestive enzyme activities, conventional organic nutrient contentsand changes of intestinal flora were determined by taking fecal samples. Results showedthat, average daily gain of broiler in the test group increased by12.01%, feed weight ratiodecreased by10.72%, diarrhea rate decreased by63.74%, mortality decreased by32.55%;activities of α-amylase, protease, lipase and cellulase in fecal samples of the test groupincreased by an average of39.82%,31.56%,44.60%and45.30%respectively, comparedwith the control group. Contents of crude protein, starch, crude fat, and crude fiberdecreased by39.74%,32.09%,28.23%and22.62%respectively, compared with thecontrol group. The quantity of coliform group decreased by34.32%and the number oflactobacteria, bifidobacteria and bacillus increased by33.52%,39.83%and33.52%respectively than that of the control group. After stopping feeding the J-4preparation,enzyme activities, conventional organic nutrient contents and microbial flora of the test group gradually approached to those of the control group.In addition, use the methods of real-time fluorescent quantitative PCR (qPCR method)to detect the impact on microbial flora.2701-day-old broilers were divided randomly intocontrol group, antibiotic group and probiotic group,0.1%J-4(living bacterium content1.0x1010cfu/g) preparation was added to the test group and antibiotics (Amikacin60mg/kg)to the antibiotic group compared with feeding basal diet to the control group, each grouphas three repetitions. The quantity of total bacteria, lactobacillus, bifidobacterium andE.coli in feces were detected by qPCR at21-day and42-day. The results showed that,compared with control group and antibiotic group, the quantity of total bacteria,lactobacillus and bifidobacterium in probiotic group had obviously improved (P<0.05);E.coli number has significantly decreased (P<0.05) compared with the control group, butno obvious difference with antibiotic group (P>0.05). The result shows that J-4agent couldincrease the total number of bacteria in intestinal tract, promote the growth of the bacteriasuch as lactobacillus and bifidobacterium, inhibit the growth of harmful bacteria such asE.coli, and have similar inhibition effect to amikacin and other antibiotics from molecularlevel, could replace antibiotics prevention. Compared with the traditional colony countingmethod, qPCR has high specificity, strong sensitivity, conveniention and fast.In study, J-4agent has the functions of prevention and control of chickens diarrhoea,reducing broiler mortality, improving poultry intestinal digestive enzyme activities,improving the feed conversion rate and maintaining the balance of intestinal flora.