| This experiment was conducted to select two lactic acid-producing strains of Bacillus sp.BLZ01 and SPL01. By using Blood Lactic Acid kit to determine lactic acid type and combining the morphological, physiochemical properties with 16S rRNA sequencing analysis, strain of Bacillus.BLZ01 and SPL01 were identified. Through the single factor experiment, the culture medium was preliminarily optimized. And to ascertain the effects of their preparation on broiler’s. The growth performance, slaughter performance, immune function and intestinal microflora. This experiment’s main contents and results are as follows:1. According to the results of bacterial culture and Gram staining, the bacteria and colony morphological characteristics of BLZ01 and SPL01 were analyzed. Combining the physiochemical properties with 16S rRNA sequencing analysis, strains of Bacillus BLZ01 and SPL01 were identified as Bacillus megaterium and Bacillus cereus, respectively.2. In this experiment, using the single factor experiment, combining the commonly used fermentation raw materials, the preliminary culture mediums of BLZ01 and SPL01 were studied. The results showed that BLZ01’s best medium were as follows:the glucose, corn flour, soybean flour, rapeseed meal, fish meal, urea, calcium carbonate, sodium chloride, magnesium sulfate and pH were 10 g/L,10 g/L,15 g/L,5 g/L,10 g/L,2 g/L,2 g/L,5 g/L,0.2 g/L and 7.2～7.5, respectively. SPL01’s as follows:the glucose, corn flour, soybean flour, rapeseed meal, fish meal, urea, calcium carbonate, sodium chloride, magnesium sulfate and pH were 10 g/L,10 g/L,10 g/L,5 g/L,10 g/L,2 g/L,5 g/L,5 g/L,0.5 g/L and 7.2～7.5, respectively.3. One hundred and fifty 7-day-old broilers were randomly divided into 5 groups, each group included 3 repeats, each repeat included 10 broilers. A was control group, feeding basal diet; B C D E were experimental groups, B was fed the basal diet supplemented with 0.05 g/kg of the BLZ01 probiotics, C was fed the basal diet supplemented with 0.05 g/kg of the SPL01 probiotics, D was fed the basal diet supplemented with 0.05 g/kg of the BLZ01 probiotics and 0.05 g/kg of the SPL01 probiotics, E was fed the basal diet supplemented with 0.1 g/kg of the BLZ01 probiotics and 0.1 g/kg of the SPL01 probiotics.(1)Growth performance:In average daily(ADG),the four experimental groups were significantly higher than the control group(P<0.05).Group D and Group E feeding with compound probiotics were higher than the control group, but difference was not significant(P>0.05).In feed conversion ratio(F/G),the four experimental groups of B C D E respectively reduced 10.0%、9.0%、10.0% and 5.7%,by comparing with control group. In slaughter performance, all experimental groups’ net rate of full-bore, pectoral rate and leg rate were significantly higher than the control group(P<0.05).Group D’s pectoral rate was significantly higher than B or C(P<0.05), Group E’s dressing percentage and leg rate were significantly higher than B or C(P<0.05).In this experiment BLZ01 and SPL01 addition significantly increased ADG, and decreased F/G And compound probiotics were better than single bacteria probiotics.(2)Immune performance:Although BLZ01 and SPL01 could improve the immune index and ND HI antibody titers of some broilers. it could not explain that they had a significant effect on the immune function of broilers.(3)Intestinal flora:In ileum, the amount of Lactobacillus and Bifidobacterium of four experimental groups were significantly higher than the control group(P<0.05),except Group C’s Lactobacillus. In cecum, the amount of Lactobacillus was higher than the control group(P>0.05). Ileum and cecum, the amount of E.coli and Enterococcus of four experimental groups were significantly lower than the control group(P< 0.05).This experiment showed that BLZ01 and SPL11 were good for the growing of Lactobacillus and Bifidobacterium, and inhibited pathogenic bacteria such as E.coli.(4)PCR-DGGE consequence:Through Quantity one analysis found that it existed respective flora in ileum and cecum, and difference was large. Even if feeding BLZOl and SPL01 couldn’t change this difference. Adding BLZ01 and SPL01 in basic diet could change intestinal flora species of ileum and cecum, and the numbers of intestinal flora were improved. Lactobacillus sp. were mainly appeared in the sequences of DNA recovered from single band in DGGE fingerprints by identified, including Lactobacillus salivarius, Lactobacillus oris, Lactobacillus and Lactobacillus delbrueckii, accounts for 44.4%.This experiment showed that BLZOl and SPL01 could increase abundance and population density of intestinal microflora in broiler. |
PDF Full Text Request