Optimization Of Technological Parameters Of Solid-state Fermentation Of Lentinus Edoides Chaff And Its Application In Sheep Diet

Fungi bran contains rich nutrients such as crude fiber,crude protein and crude fat,which can be used as animal feed and so on,and can be recycled to achieve economic development.In this experiment,Lentinus edoides chaff was taken as the research object,and a juicy feed with rich nutritional value and good palatability for ruminants was produced by solid fermentation technology of bacteria and enzyme.Objective:Based on the abundant of spent mushroom substrate resources in Hotan,this study aimed to screen out the optimal combination of bacteria and enzymes for fermenting Lentinus edoides chaff,and optimized the fermentation process parameters of Lentinus edoides chaff by using fuzzy mathematics membership function method.The fermentation quality of spent mushroom bran treated by different combination of bacteria and enzymes was comprehensively evaluated,and the effects of spent mushroom bran fermented feed on growth performance and digestion and metabolism of sheep were studied.Methods:Experiment 1:In this study,the single factor experiment design was used to screen 16different bacteria and enzymes preparations composed of 5 kinds of bacteria（Lactobacillus buchneri（W1）,Candida utilis（W2）,Lactobacillus acidophilus（W3）,Lactobacillus plantarum（W4）,Aspergillus niger（W5））and 2 kinds of enzymes（xylanase（M1）and cellulase（M2））.The sensory indexes of fermentation products were evaluated,and p H value and nutrient content indexes were determined.Experiment 2:According to the different bacteria and enzymes combinations screened in Experiment1,the fermentation process parameters of bacterial bran were further optimized.L₁₆（4⁵）orthogonal test was used to design five experimental factors and four levels as follows:corn addition（4%,5%,6%,7%）,substrate moisture content（54%,58%,62%,66%）,bacterial enzyme composition（W1+W2+W3+W5+M1+M2,W1+W2+W3+M1+M2,W1+W2+W4+M2 and W1+W2+W4+W5+M1+M2）,and bacterial enzyme inoculation amount（0.7%,1.4%,2.1%,2.8%）.Fermentation time（30 d,40 d,50 d,60 d）,a total of 16 treatments,through the sensory evaluation of bacterial chaff after fermentation of different treatment combinations,and the determination of p H value and nutrient content,through orthogonal test analysis of variance and multiple comparison,the optimal fermentation process parameters such as corn addition,substrate moisture content,bacterial enzyme composition,bacterial enzyme inoculation amount and fermentation time were obtained.The feed safety evaluation of the fungus chaff raw materials and fermentation products was carried out.Experiment 3:48 4-month-old Altay rams with similar test weight（31.74±2.61kg）and good physical condition were randomly divided into four groups,including one control group and three experimental groups.The control group was fed with basic diet,and the experimental group was fed with fermented mushroom bran to replace 12%,24%and 36%of the basic diet,respectively.The whole trial period lasted for 60 days,including the pre-trial period of 15 days and the trial period of 45 days.The growth performance,serum biochemistry,rumen fermentation and apparent digestibility of nutrients of sheep were measured.Results:（1）After the Lentinus edoides chaff was fermented by the combined preparation of bacteria and enzyme,the sensory index scores were all good or above,the p H value was significantly lower than that of raw materials,and the nutritional components were improved.Finally,four optimal combinations of bacterial enzyme preparation were determined.（2）Through orthogonal test,it was found that the main factor affecting the fermentation quality of Lentinus edoides chaff was corn addition,followed by substrate moisture content,microbial enzyme composition,microbial enzyme inoculation amount and fermentation time.The optimum fermentation parameters of Lentinus edodes bran were determined as follows:corn addition 6%,substrate moisture content 66%,microbial enzyme composition W1+W2+W4+W5+M1+M2（i.e.Lactobacillus Brucella,Candida utilis,Lactobacillus plantarum,Aspergillus niger,xylanase and cellulase）,microbial enzyme inoculation 2.8%,and fermentation time 30 d.The contents of heavy metals,mycotoxins and other harmful substances in fermented bran meet the hygienic standards of feed.The feeding safety of fermented mushroom bran feed was determined to ensure its normal use in production.（3）The application effect of fermented mushroom bran as feed in sheep was studied.There is little difference in growth performance,serum biochemistry and apparent digestibility of nutrients of sheep in the 12%substitution group of fermented bacterial bran,among which there is no significant difference in daily gain,feed-to-weight ratio,serum biochemistry index and nutrient digestibility between the two groups.Therefore,the 12%substitution group can be selected in production.Conclusion:The main factors affecting the fermentation quality of Lentinus edoides chaff are as follows:corn addition>substrate moisture content>bacterial enzyme composition>bacterial enzyme inoculation amount>fermentation time.The optimum fermentation parameters of mushroom bran were A₃B₄C₄D₄E₁,i.e.corn addition 6%,substrate moisture content 66%,enzyme composition W1+W2+W4+W5+M1+M2（i.e.Lactobacillus brucella,Candida utilis,Lactobacillus plantarum,Aspergillus niger,cellulase and xylanase）,inoculum 2.8%,fermentation time 30 d.The contents of heavy metals,mycotoxins and other harmful substances in fermented bran conformed to the hygienic standards of feed.In production,fermented mushroom bran can be selected to replace sheep basal diet,and the proportion of 12%is more suitable.