Preliminary Research Of Silkworm Pupae And Biological Feed Solid-state Fermentation By Mixed Bacteria

In recent years, with people increasing demand for meat, milk and eggs aquatic products,livestock and poultry and aquaculture industry got rapid development. Fish meal demand alsowill increase, as the mainly feed protein in the breeding. But fish meal was in short supplybecause of production decline year by year caused by serious damage of marine fisheryresources, with the scale expansion and intensive farming improved recently. To meet thedemands of the development of breeding, people began to look for alternative protein sourceof plant and animal that is cheaper than fishmeal. However, some animal and plant proteinsource cannot totally replace fish meal because they contained some nutritional factors.Fermentation is an effective method to improve the feed utilization of plant and animal feedby dealing with it. Fermented feed not only can improve the content of protein and othernutrients, and degrade macromolecule material in the feed into small molecules that can beabsorbed easily through biodegradation. Peptide is the intermediate in the degradation ofproteins into amino acids, can be absorbed directly to use in the intestine of animals.Silkworm was developed in our country, and the chrysalis resources are rich. Silkwormchrysalis is a potential alternative insect protein source to replace fish meal, known as its highprotein content, balanced and various amino acid, and has a great application prospect in thefeed. Plant protein source, such as soybean meal and rapeseed meal, had been widely used infeed, but its antinutritional factors limited its use. The aim of this study was to evaluate thebest carbon source and the appropriate adding amount of silkworm chrysalis fermentation bythe Bacillus subtilis through Bacillus subtilis or probiotics solid-state fermentation, with theacid soluble protein as the main index, as well as changes of full price feed nutrientcomposition and quality by probiotics fermentation, silkworm chrysalis fermentated byprobiotics, feed quality and the technological parameters of rapeseed meal and bran. Thestudy provided theoretical basis and referential information for the fermentation technology offeed ingredients, such as silkworm chrysalis.(1) Crude protein and acid-soluble protein content were58.33%and13.96%after konjacflour was added,were significantly higher than other carbon sources,and were no significantgroup differences in the flour and crude protein content of rice bran group.The Lowest crude protein content of wheat bran was47.75%,acid-soluble protein content was12.96%,wassignificantly lower than konjac flour and rice bran group and was no significant differencebetween the powder group.According to different effects on the fermentation, fermented pupaprotein content was significantly lower with the addition of konjac flour rosing.5%konjacflour group was the highest,but20%was the lowest.While5%and10%konjac flour group ofacid-soluble protein content was significantly lower than the15%konjac flour groups,andthere were no significant differences between the15%and20%konjac flour groups.(2)When using probiotics and bran as a carbon source fermentation pupa and rapeseedhybrid protein material, the different fermentation process makes different effects on feedquality.Probiotics inoculum15%,water ratio of1:0.5, under the conditions of fermentationtemperature30℃and fermentation three days, the fermented feed up to47.01%crudeprotein, acid-soluble protein content of10.27%, protein solubility of46.91%lactic acidcontent was6.84%, free amino acid content of4.6%and pH reached3.95, the feedingredients contains a high number of viable cells.Fermented feed is golden brown,texture ofdry bulk,pup effectively removed odors and with a sour flavor.(3) The effects of full price feed fermentation by probiotics were observed as follows: theprotein content of the full price feed after fermentation was44.58%, significantly higher thanthat of unleavened full price feed, and increased by7.76%. The acid soluble protein content offull price feed after fermentation increased to6.01from3.88in unleavened, and increased by54.9%, significantly higher than that in the feed. In addition, fermentation feed has increasedthe number of the probiotic bacteria in the feed. At the same time, pH in the feed reducedfrom6.32to6.32, with acid fragrance, improving the feed palatability, promote animalfeeding.Conclusion：Konjac flour is the best carbon source of Bacillus subtilis fermentationpupa,dosage can be fermented to achieve the best results when added15%-20%;when usingprobiotics and bran as a carbon source fermentation pupa and rapeseed hybrid protein material,probiotics inoculum15%, water ratio of1:0.5, under the conditions of fermentationtemperature30℃and fermentation three days, can get the best fermentation results,fermentedfeed is golden brown,texture of dry bulk,pup effectively removed odors and with a sourflavor;so probiotics fermentation nutritionally complete feed can significantly improve thenutrient content of feed,and improve feed quality.