Study On Synergistic Solid-state Fermentation Of Wheat Bran By Bacteria And Enzymes And Its Value For Goose Feeding

This experiment aims to study the process conditions of solid-state fermentation of bran by bacteriophage enzymes,evaluate its effect on the feeding value of geese,and provide reference data and a theoretical basis for applying fermented bran in geese production.Experiment 1:Exploration of the process of solid-state fermentation of bran by Bacillus subtilis,Pseudomonas aeruginosa,and Lactobacillus plantarum as fermenting strains,and cellulase,phytase and acid protease as compound enzyme preparations,and the additional levels of Bacillus subtilis,Pseudomonas aeruginosa,Lactobacillus plantarum,cellulase,phytase,and acid protease were investigated by single-factor test and orthogonal test,respectively.The optimal fermentation temperature,material-to-water ratio,and fermentation time were screened and optimized by Box-Behnken test with orthogonal test and response surface analysis,and the weighted indices of neutral detergent fiber degradation rate,phytate phosphorus degradation rate,and crude protein growth rate were used as response values to determine the bran bacterial-enzyme synergistic solid-state fermentation process.The apparent metabolic energy,authentic metabolic energy,and nutrient utilization of fermented wheat bran(FWB)in geese were also determined by in vivo digestion and metabolism tests on adult male geese at 280 days of age with the evacuation-strong feeding method.In the second experiment,360 1-day-old Yangzhou geese were randomly divided into five treatment groups with six replicates of 12 geese each for 63 d.The control group(group A)was fed corn-soybean meal-based rations,while the experimental groups B,C,D,and E were fed rations with 2%,4%,6%,and 8%FWB,respectively.The optimum amount of FWB in the diet for geese from 1 to 63 days of age was determined by analyzing growth performance,immune index,serum index,and intestinal health.The test results showed that:(1)The addition of 4.0‰ cellulase and 1.0‰ phytase significantly reduced the levels of NDF and PA in wheat bran,respectively(P<0.05),and the addition of 0.5‰ acid protease could substantially increase the level of CP in wheat bran(P<0.05).Combined with the orthogonal test and response surface test design optimization,the optimal fermentation process parameters were:25%Pseudomonas aeruginosa,15%Bacillus subtilis,20%Lactobacillus plantarum,3.5‰ cellulase,1‰ phytase,0.75‰ acid protease,59.5 h fermentation time,1:1.3 material to water ratio,and 32℃ fermentation temperature.(2)The contents of PA and NDF in FWB were 60.94%and 17.43%lower than those of unfermented bran,and the levels of CP,ASP,and TAA were 22.98%,77.49%,and 21.53%higher than those of unfermented bran,respectively.The results of emptying-strong feeding metabolism showed that CP and TP utilization was significantly higher in the fermented bran group compared to the unfermented bran group(P<0.05),and the differences in the effects on AME,TME,EE,and CF were not significant(P>0.05).(3)The use of 6%and 8%FWB in the diet significantly increased the body weight of 21-day-old goslings(P<0.05),6%and 8%FWB significantly increased the body weight of 42-day-old goslings(P<0.05),and 6%FWB significantly increased the body weight of 63-day-old goslings(P<0.05).The addition of 6%and 8%FWB can significantly increase ADG(P<0.05)and substantially reduce F/G(P<0.05)of 1-21day old goslings;2%and 4%FWB can significantly increase ADFI(P<0.05)of 43-63-day-old goslings,and 6%FWB can significantly reduce F/G(P<0.05)of 43-63-day-old goslings.(4)The addition of 4%,6%,and 8‰ FWB in the diet could significantly reduce the serum SS content of 21-day-old goslings(P<0.05)and significantly increase the serum IGF-1 and T3 range(P<0.05);6%and 8%FWB could increase substantially the serum GH,T3 and T4 content of 42-day-old goslings(P<0.05),and the addition of different levels of FWB could significantly reduce The addition of different levels of FWB could substantially lessen the serum SS content of 42-day-old goslings(P<0.05);6%FWB could increase the serum GH and T3 content of 63-day-old goslings(P<0.05)significantly and significantly reduce the serum SS content(P<0.05).Different levels of FWB could substantially increase the serum T3 and T4 range of 63-day-old goslings(P<0.05).6%and 8%FWB could significantly increase the serum T3 and T4 content of 63-day-old goslings(P<0.05).The serum IgA,IgM,and IgG levels of 21,42 and 63-day-old goslings were significantly increased by 6%and 8%FWB(P<0.05).2%FWB significantly increased serum SOD levels of 21-day-old goslings(P<0.05);4%and 6%FWB significantly increased serum SOD levels of 42-day-old goslings(P<0.05),and 2%FWB significantly decreased serum MDA levels of 42-day-old goslings(P<0.05);4%FWB can substantially increase the serum CAT content of 63-day-old goslings(P<0.05).(5)The total volatile fatty acid concentrations in the cecum of all treatment groups with different levels of FWB tended to increase compared with the control group(P=0.057).2%and 6%FWB significantly increased the concentration of acetic acid in the cecum(P<0.05),6%and 8%FWB significantly increased the concentration of isobutyric acid in the cecum(P<0.05),2%and 6%FWB significantly increased the concentration of butyric acid in the cecum(P<0.05),and 2%and 6%FWB significantly increased the concentration of butyric acid in the cecum(P<0.05).2%and 6%FWB significantly increased the concentration of butyric acid in the cecum(P<0.05),and the addition of 4%and 6%FWB significantly increased the concentration of valeric acid in the cecum(P<0.05).(6)The addition of different levels of fermented bran improved the intestinal tissue structure.Adding 4%FWB significantly reduced the crypt depth in the jejunum of 21-day-old goslings(P<0.05).The addition of 6%FWB significantly increased the thickness of the muscular layer and the length of the ileal villi in the jejunum of 21-day-old goslings(P<0.05)and significantly reduced the thickness of the muscular layer in the ileum(P<0.05);the addition of 4%FWB significantly reduced the crypt depth in the ileum of 42-day-old goslings(P<0.05);The addition of 4%,6%and 8%FWB could significantly increase the length of jejunal villus height in 63-day-old goslings(P<0.05),and the addition of 6%and 8%FWB could substantially increase the thickness of the muscular layer(P<0.05).(7)6%FWB significantly increased the activity of pepsin and pancreatic lipase in 21-day-old goslings(P<0.05),4%FWB significantly increased the activity of pancreatic trypsin in 21-day-old goslings(P<0.05),and 8%FWB significantly increased the activity of jejunum α-amylase,pancreatic protease,The action of α-amylase in the jejunum,pancreatic protease,lipase and ileum of 21-day-old geese was significantly increased by 8%FWB(P<0.05),and the activity of α-amylase in the pancreas,jejunum and ileum of 42-day-old geese was significantly increased by 6%FWB(P<0.05).α-amylase exercise in the duodenum of 42-day-old geese was significantly increased by 4%FWB(P<0.05).α-amylase activity in 42-day-old goslings(P<0.05)and different levels of FWB could significantly increase pancreatic trypsin activity in 42-day-old goslings(P<0.05).6%FWB could significantly increase pancreatic pepsin and lipase activity in the pancreas and jejunum of 63-day-old goslings(P<0.05),and the addition of 6%and 8%FWB could significantly increase pancreatic lipase activity in 63-day-old goslings(P<0.05).The addition of 6%and 8%FWB significantly increased the activity of lipase and trypsin in the jejunum,ileum,and midgut of 63-day-old goslings(P<0.05),4%,6%,and 8%FWB significantly increased the activity of pancreatic trypsin in 63-day-old goslings(P<0.05),and,the addition of 4%and 6%FWB significantly increased the activity of α-amylase in the jejunum of 63-day-old goslings(P<0.05)(8)Observed-Species index,Ace index,Shannon index,Simpson index,Chaol index,and PD-whole tree index were not significantly different among the groups(P>0.05).The dominant species in both treatment groups were Firmicutes and Bacteroidota;the most distributed species at the genus level were CHKCI001 and Alistipes.In addition,the FWB additive group of Romboutsia and Methanobrevibacter was more abundant than the control group.In conclusion,the bran fermentation by mycobacterial enzymes synergistically increased CP,ASP,and TAA contents,decreased PA and NDF contents,and improved the utilization of their nutrients by geese.The addition of different levels of FWB could improve the growth performance of 1-63 days old goslings,improve the serum hormone content and serum antioxidant performance of goslings,regulate the immune function of the body,improve the morphology of the intestinal tract,increase the digestive enzyme activity and cecum VFA concentration,and maintain the stability of the cecum microbiota.Combined with the experimental results,the appropriate level of FWB supplementation in geese rations was recommended to be 6%.