| Rapeseed meal(RSM)is widely used in animal diets,but its effective application in animal diets is limited because it contains many antinutritional factors such as glucosins and tannins.At present,double low rapeseed meal with low glucosinolate and low erucic acid has appeared on the market,but its glucosinolate content still exceeds the maximum tolerance amount of animal body.In recent years,more and more researchers began to study different ways of pretreatment rapeseed meal to make it more effective use.In this paper,the rapeseed meal was pretreated by enzymolysis,solid-state fermentation and bacteria-enzyme cooperation,and the content of nutrients and anti-nutrition factors of rapeseed meal after treatment was determined,and a more effective treatment method was obtained.Subsequently,the third generation of animal biomimetic digestive system was used to simulate the gastric and intestinal fluid of growing pigs for in vitro digestion test,and the digestion and utilization effects of different treatments of rapeseed meal were evaluated,which provided a certain basis for efficient utilization of rapeseed meal raw materials and solving the feed cost problem.1.Activated Bacillus amylolitica TL106 was inserted into a fermenter equipped with 11 L enzyme induction medium at a inoculum rate of 1.5%,and fermented under certain fermentation conditions.The enzyme activities of cellulase,xylanase,glucanase,amylase and protease were measured at different time points.Stop fermentation and lyophilize to prepare enzyme powder;Then,different proportions of enzyme meal were added to hydrolyze rapeseed meal,the water content was set to 82%,and the concentration of rapeseed meal and water substrate was set to0.2g /m L.Four treatment groups were set.Treatment 1: rapeseed meal raw materials were treated with no enzyme meal,treatment 2: rapeseed meal ratio was 1:10,treatment 3: rapeseed meal ratio was 1:25,treatment4: rapeseed meal ratio was 1:50.After enzymatic hydrolysis at 37℃ and220 rpm for 48 h,the nutrients of rapeseed meal were determined after drying and grinding.The results showed that the fermentation was stopped at 26 h,and the activities of protease,amylase,xylanase,glucanase and cellulase were 4963.890 U/m L,537.951 U/m L,62.404U/m L,57.259 U/m L and 35.092 U/m L,respectively.After enzymatic hydrolysis,the contents of nutrients in rapeseed meal in all treatment groups were significantly increased(P < 0.05),and the contents of anti-nutrition factors were significantly decreased(P < 0.05).Compared with treatment 1(rapeseed meal group without enzyme meal),the contents of acid-soluble protein and small peptide were increased by4.11% and 35.94%,respectively.The Neutral detergent fiber(NDF)and Acid detergent fiber(ADF)were reduced by 22.63%,28.84% and13.42% respectively.2.One strain with better performance was selected from 10 strains of Lactobacillus plantarum and activated with Bacillus amyloliticus TL106 and Saccharomyces Bradi MAFIC 1703 to produce seed liquid solid fermented rapeseed meal,in which the ratio of rapeseed meal to wheat bran was 9:1,the water content was 30%,the added amount of brown sugar was 5%,and the inoculation amount was 15%.L9(34)three-factor and three-level orthogonal test was performed.After fermentation at 37℃for 3 days,the contents of nutrients and anti-nutrition factors were determined,and the best treatment group was selected.The results showed that Lactobacillus plantarum GY3,which had the most outstanding acid production and bacterioinhibitory performance,was screened and combined with TL106 and MAFIC 1703 in different proportions to ferment rapeseed meal.All the treatments could improve the content of nutrients in rapeseed meal and reduce the content of anti-nutrition factors in rapeseed meal to different degrees.Among them,group E(the seed amount was 15%,GY3: TL106: MAFIC-1703= 2:2:2)compared with rapeseed meal raw material group without bacterial solution,the treatment effect was the best,the crude fat content increased by 78.69%,the small peptide content increased by 38.33%,the acid detergent fiber decreased by 10.24%,the glucoside content decreased by12.50%.3.Using the conditions of enzymatic hydrolysis and fermentation screening of the first two parts,rapeseed meal and enzyme meal were dried and pulverized at 1:10 enzymatic hydrolysis for 48 h,and then at15% inoculated amount of bacteria,GY3: TL106: MAFIC-1703 mixing ratio 2:2: 2.The ratio of rapeseed meal to wheat bran was 9:1,the water content was 30%,the added amount of brown sugar was 5%,and the composition was determined after 3 days of fermentation at 37℃.The results show that: Compared with the control group(untreated rapeseed meal),the bacterial enzyme cooperative two-step treatment was more effective.Compared with the control group(untreated rapeseed meal),the crude fat content increased by 37.61%,the acid-soluble protein content increased by 470.59%,the small peptide content increased by 22.67%,the neutral detergent fiber decreased by 36.51%,and the acid detergent fiber decreased by 35.51%.Glucoside content decreased by 43.79%.4.Animal biomimetic digestion test was carried out on rapeseed meal after different treatments.There were two different stages:(1)three different treatments of rapeseed meal groups,untreated rapeseed meal groups and soybean meal groups(raw material stage);(2)corn aniseed combined with three different treatments of rapeseed meal groups,corn combined with untreated rapeseed meal groups and corn soybean meal base groups(feed stage).(3)The cooperative treatment of viable bacteria and sterilization of rapeseed meal by fermentation and bacterial enzyme.The results show that: The results of raw material stage showed that compared with soybean meal group,the dry matter mass,dry matter digestibility,digestible energy value and energy utilization rate of untreated rapeseed meal group were significantly lower than those of soybean meal group(P < 0.05),and the dry matter digestibility of enzymatic hydrolysis rapeseed meal group was 31.18% higher than that of untreated rapeseed meal group(P < 0.05).The energy utilization rate of mixed bacteria fermented rapeseed meal group was increased by50.48%(P < 0.05).The results of diet stage showed that the energy utilization rate of untreated rapeseed meal diet group was significantly lower than that of corn soybean meal diet group(P < 0.05),and the dry matter digestibility of fermented rapeseed meal corn diet group was14.34% higher than that of untreated corn rapeseed meal group(P < 0.05).The energy utilization rate of enzymatic hydrolysis rapeseed meal corn diet group was significantly increased by 498.51% compared with that of corn untreated rapeseed meal group(P < 0.05).The results of live bacteria and sterilization stage showed that the dry matter digestibility of live bacteria treatment group was significantly higher than that of sterile treatment group(P < 0.05).In conclusion,three different treatments of rapeseed meal,namely fermentation,enzymolysis and bacterial enzyme coordination,can improve its nutritional value in different degrees.Among them,bacteria-enzyme cooperative treatment is more efficient.The feasibility of different treatments of rapeseed meal was further verified by in vitro biomimetic experiment evaluation,which provided certain reference significance for efficient utilization of rapeseed meal to a certain extent. |
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