A Preliminary Study On The Application Of Fermented Bean Dregs In Feed For Largemouth Bass

Protein is not only an important nutrient that limits the growth of fish but also a key factor in determining the cost of feed formulations.So it is the focus of long-term commitment to nutritionists that how to effectively improve the efficiency of protein utilization or the development of new protein source.Micropterus salmoides is an important freshwater aquaculture fish in China,but in recent years,the rapid decline in farming efficiency,because of the lack of nutrition and feed parameters and high prices of fish meal.Bean dregs is rich in protein,fat,dietary fiber.In the dry matter of bean dregs.In addition also contains rich soybean is flavones and soybean polysaccharides.Therefore,bean dregs not only has high nutritional value,and high medicinal value,the thorough research and development,can greatly improve its added value.Has caused Japan,the United States attaches great importance to.Microbial fermentation can not only improve feed palatability,improve efficiency,and can expand feed resources.Fish with bean dregs as compound feed raw materials,saves the resources,and protect the breeding environment,and reduce the disease occurs,fully staffed,shall provide it.Solid state fermentation bean dregs using mixed bacteria,fermentation pH=7.0,fermentation temperature 28 ?,and fermentation time 72 h to make fermented bean curd.Determination of crude protein,crude fat,crude fiber before and after fermentation,amino acid content changes.Results show that not compared with fermented bean dregs nutrition composition,fermented bean curd fermented bean curd crude protein increased by 14.8%,crude fat by 17.5%,crude fiber 49.3% lower;A 58.03% increase in total amino acid,lysine,valine,methionine,phenylalanine,glutamic acid content increased by 31.9%,36.8% and 36.8% respectively,35.2%,31.2%.A feeding trial was conducted to investigate the effects of partial replacement of soybean meal with fermented soybean residue on growth performance,body composition and plasma biochemical parameters of largemouth bass,Micropterus salmoides.Soybean residue was fermented with a mixture of microorganisms(Bacillus subtilis,Lactobacillus spp.and Molasses yeast)using the solid-state fermentation.Four isonitrogenous(crude protein 430 g/kg)and isoenergetic(gross energy 18 MJ/kg)diets were formulated by replacing 0(the control),8%,16% and 24% of protein from soybean meal with fermented soybean residueEach diet was fed to four replicate groups of fish(initial body weight: 17.1 ± 0.19 g)for 12 weeks.Resultsshowed that dietary FSR substitution significantly improved growth of juvenile largemouth bass.The weight gain,specific growth rate and protein efficiency ratio were all significantly improved by dietary FSR level up to 16% substitution level(P<.05)and then levelled off beyond this level.Fish fed the diet with 16% and 24% protein from fermented soybean residue had lower feed conversion ratio than the control group(P<.05).The hepatosomatic index,viscera ratio and liver lipid content significantly decreased with increasing dietary fermented soybean residue level.Total protein content,superoxide dismutase and alkaline phosphates activities in plasma were lower in fish fed the control diet(P<.05)than the other groups.However,both alanine aminotransferase and aspartate transaminase were higher in fish fed the control diet(P<.05)compared to the other treatments.The plasma catalase activity significantly increased with increasing dietary fermented soybean residue level,while plasma triglyceride,total cholesterol,glucose and MDA contents significantly reduced.No significant difference was observed in the glutathione peroxidase activity among dietary treatments.These findings demonstrated that replacing dietary soybean meal with fermented soybean residue has beneficial effects on growth of M.salmoides,and the best growth performance was obtained at 16%replacement for soybean meal protein.In addition,there is a great potential to apply fermented soybean residue to improve lipid metabolism and antioxidant capacity of M.salmoides.