Optimization Of Fermentation Condition And Evaluation Of Nutritional Value Of Wet Corn Gluten Feed

Wet corn gluten feed(WCGF)is a kind of by-products in the starch production,which mainly includes the corn husk and the exudate produced during the production and processing.Due to the high water content of fresh raw materials,mildew and stink,inconvenience of transportation and poor adaptability in the wet corn gluten feed,WCGF has not been widely used in the process.Using yeast for fermentation,solid fermentation of wet corn gluten feed material by the double factor test,the optimum fermentation conditions of yeast concentration pH of the culture medium,the best wine has determined by fermentation.And the fermentation quality,optimization of fermentation producted after the nutritional value,rumen degradation and determination parameters of small intestine digestibility.Fermented wet corn gluten feed(FWCGF)has provided a theoretical basis for pasture application.Experiment?:Optimization of technological conditions of wet corn gluten feedThe inoculation amount of pH(4,4.5,5)and Saccharomyces cerevisiae(10~5 CFU/g,10~6 CFU/g,10~7 CFU/g)was set in this experiment.There were nine treatment groups and three repeat in each treatment group.After 15 d fermentation,the sensory evaluation of the fermented feed was carried out,and the nutrients,fermentation indexes and microbiological indexes of each group were measured.The results showed that when the pH was 4.5 and the inoculation amount was 10~6 CFU/g,the color of the fermented feed was similar to the raw material color,the smell was fragrant,the mildew free deterioration appeared,and the number of yeast increased,the number of mould decreased and the ammonia nitrogen concentration was less than 10%,indicating that the fermentation quality was the best and the fermentation effect was the best.Experiment ?:Determination of oxygen stability of fermentation products under optimum conditionsAerobic stability refers to the time when silage fermented feed was completely exposed to air and remains stable.It was an important index to measure feed fermentation quality.The experiment was conducted to monitor the temperature of the fermented wet corn fiber feed and the raw material of wet corn fiber feed under the optimum fermentation conditions.The results showed that the temperature of the feed sample was 68 h in the air,and the temperature of the feed sample was higher than that of the ambient temperature at 2 degrees centigrade.This was because the aerobic microorganisms in the wet corn fiber feed began to reproduce in large quantities under the aerobic condition.The heat generated by the microbial multiplication activity leads to the increase of temperature,and the central temperature of the fermented wet corn fiber feed is not more than 2 centigrade during the 15 days of aerobic exposure,which shows that the aerobic stability of the wet corn fiber feed can be effectively improved when the inoculation amount of Saccharomyces cerevisiae in the wet corn fiber feed is 10~6 CFU/g under the optimum pH condition.Experiment ?:To evaluate the nutritional value of FWCGF and WCGF by using the CNCPS system and the NRC(2001)modelThe nutritional components of wet corn gluten feed before and after fermentation were determined by CNCPS system,and the protein and carbohydrate fractions were systematically dissected to predict its potential nutritional value.The NRC(2001)model was applied to estimate digestible nutrients and Energy.The test results showed that:(1)The content of dry matter,fat,soluble crude protein,crude protein,non protein nitrogen and neutral detergent insoluble protein in the fermented wet corn fiber feed was significantly higher than that of wet corn fiber feed(P<0.05).(2)The carbohydrate content of wet corn fiber feed was significantly higher than that of fermented wet corn fiber feed(P<0.05).(3)The rumen degradable protein of the fermented wet corn fiber feed was significantly higher than that of the wet corn fiber feed,while the rumen bypass protein of the fermented wet corn fiber feed was significantly lower than that of the wet corn fiber feed(P<0.05),and the content of the absorbed rumen protein and the metabolizable protein content of the wet corn fiber feed was significantly higher than that of the fermented wet corn fiber feed(P<0.05).(4)The content of true digestible crude protein before and after fermentation was significantly different(P<0.05),and the fiber content of fermented wet corn fiber feed was significantly higher than that of wet corn fiber feed.It showed that fermentation could improve the nutritional value of wet corn fiber feed.Experiment ?:The parameters of rumen degradation before and after the fermentation of wet corn fiber feedIn this study,nylon bag degradation method was used to evaluate the nutritional value of fermented wet corn fiber feed.The degradation rule of dry matter,crude protein and neutral detergent fiber in rumen of fermented corn fiber feed before and after fermentation was determined respectively.The results showed that:(1)The degradation rate of dry matter was increased by fermentation;The crude protein degradation rate of the fermented wet corn fiber feed was more than 80%after 36 h,which was significantly higher than that of wet corn fiber feed(P<0.05);In 4 and 8 h,the rumen degradation rate of the neutral detergent fiber for the fermented wet corn fiber feed was significantly higher than that of the wet corn fiber feed(P<0.05).(2)The total digestible protein content of fermented wet corn fiber feed is higher than that of wet corn fiber feed.(3)The absorption of endogenous protein and endogenous protein in the small intestine of fermented wet corn fiber feed was significantly lower than that of wet corn fiber feed(P<0.05).In summary,wet corn fiber feed after adding Saccharomyces cerevisiae fermented in solid form.Through the determination of sensory evaluation,aerobic stability,nutrition index and rumen degradation parameter,it is concluded that wet corn fiber feed a kind of high safety,high nutritive value,and storage resistant cow feed.