Study On The Solid-state Fermented Soybean Residue By Mixed Bacteria And Its Application In Broilers

In this study, soybean residue is used as the main raw material of the fermentation basal medium, microbial fermentation of cellulase activity, amylase activity and matrix crude protein content as the main measuring indicators, mixed bacteria solid-state fermentation soybean residue is studied systematically. By the strain screening test, the best strain combinations and inoculation ratio are determined; by the single factor experiment, optimal inoculum size, incubation time, the ratio of material to water, incubation temperature and initial pH value of medium are studied, enzyme activity, crude protein content, solids content before and after fermentation are compared, yield of solids content and crude protein content are calculated; 608-day-old broilers are selected, divided into control group (basal diet),groupl (5% dry soybean residue +5% fermented soybean residue) and group 2 (10% fermented soybean residue); by the study of growth performance, immune organ index, amylase and protease activity in the small intestine and cecal flora of the broilers, impact of fermented soybean residue on the broiler production are evaluated preliminarily. Results are as follows:1. In the strain screening test, the highest crude protein content of matrix is by Bacillus subtilis PabO2 fermentation, and cellulase and amylase are also reached 14.84U and 2.17U respectively, therefore, PabO2 are identified as the main fermentation strain and are mixed fermentation with other strains; in the mixed bacteria fermentation soybean residue test, the highest crude protein content of matrix and enzyme activity is by Bacillus subtilis Pab02+YeastY2+Fungi W7, then PabO2+W7+Y2 is identified as the best fermentation combination; by the inoculation ratio optimization test, the best inoculation ratio of PabO2:W7:Y2 is 4:1:1.2. In the mixed bacteria fermentation condition optimizing test, optimal inoculum size is 3%, incubation time is 36h, the ratio of material to water is 1:1, incubation temperature is 36℃and initial pH value of medium is 6.0. Under the optimal fermentation conditions, cellulase and amylase in the matrix are reached 25.20U,4.18U respectively; matrix solids content after fermentation declines (P<0.05), yield of solids content is 82.56% of which before fermentation; matrix crude protein content after fermentation increases by 6.73%, significant difference(P<0.05), yield of crude protein content is 103.14%.3. In the animal experiments, growth performance of broilers in group 1 is significantly improved(P<0.05), and which in group 2 isn't significantly improved(P<0.05). compared with control group, immune organ index in group 1 increases, but no significant difference(.P>0.05), bursal index in group 2 is slightly lower than control group, thymus and spleen index in group 2 are higher, but no significant difference(.P>0.05). the duodenal enzyme activity in group 1 and 2 are higher than control group, but compared with group 1, the duodenal enzyme activity in group 2 isn't significant different(P>0.05); prolease activity of the jejunum contents in group 1 is slightly lower than that in control group, the other enzyme activity in the jejunum are higher, all the jejunum enzyme activity in group 2 are higher than that in control group, and amylase activity is significantly higher(P<0.01); all the enzyme activity of the ileum in group 1 are significantly higher than that in control group except prolease activity of the ileum contents(P<0.05), prolease activity of the ileal wall in group 2 is significantly higher than that in control group(P<0.01), others are significantly higher(P<0.05). the number of cecal aerobic bacteria and E. coli in group 1 and group 2 decreases,'the number of Lactobacilli increases, the number of aerobic bacteria and E. coli in group 1 and group 2 significantly decreases(P<0.05), and the number of Lactobacilli in group 2 increases significantly(P<0.05).The above, after fermenting soybean residue by mixed bacteria in accordance with the best strain combinations, inoculation ratio and fermentation condition, matrix enzyme activity is high, matrix protein content increases significantly; and after adding appropriate amount of fermented soybean residue to the basal diet, the production performance of broilers is promoted.