Study On The Fermentation Of Mulberry Leaves And Its Degradation Characteristics In Beef Cattle

Shortage of feed resources has become the most important factor restricting the development of breeding industry in our country.And the mulberry is included in our forage catalog by the Ministry of Agriculture As a new type of feed resources,mulberry,with nutrient-rich,high quality,high feed value,is great potential for development.Some studies have shown that mulberry play an important role in feeding to improve the quality of livestock and poultry aquatic products,but there will be problems such as declining feed intake and low content of dietary supplement and declining growth rates in the breeding process.In recent years,there has begun large-scale cultivation of feed mulberry,and made use of mechanized harvesting way to reduce production costs in some places,This makes the content of the lignin and crude fiber increase in mulberry leaves feed,and animal feeding difficulties,which affects the development of feed mulberry industry.Therefore,in this article,with the use of the method of in vitro fermentation,the suitable strains to improve the quality of mulberry leaf has been screened out.And then I analyze the colony and cell characteristics and the enzyme activity,and comprehensively understand their physiological and biochemical characteristics.These parameters of mulberry leaf fermentation are optimized to improve the feed quality of mulberry leaves.At the same time,the digestibility of the main nutrient components in the rumen of beef cattle is determined,and the degradation characteristics of mulberry leaves are obtained.The main findings are as follows: 1 Screening suitable strains for mulberry leaves fermented by single strainThe appearance,pH and crude fiber,crude protein and crude fat content are observed and measured after selecting respectively 18 strains of four kinds of bacteria which are commonly used in feed fermentation.The result shows that the morphological,pH and crude fiber,crude protein and crude fat content of the mulberry leaves are significantly changed by fermentating with different strains(P <0.05).The content of crude protein is the highest in the fermentation products of Trichoderma harzianum(No.40505),which reached 31.27%.Bacillus cereus(No.19375)has the lowest crude fiber content of 12.71%.The crude fat content of Lactobacillus plantarum(No.21801)is the highest,reaching 5.71%.The four strains of Trichoderma koningii,Candida albicans,Bacillus cereus and Lactobacillus plantarum were used as suitable strains to improve the quality of mulberry leaves.2 Physiological and biochemical characteristics of suitable strainsThe physiological and biochemical characteristics of four suitable strains are observed by observing the characteristics of colonies and bacteria,as well as the characteristics and growth curves of four suitable strains.The results show that four strains are identified as Trichoderma koningii,Candida albicans,Bacillus cereus and Lactobacillus plantarum,respectively.Among of them have protease,cellulase and lipase activity,among which the activity of Trichoderma spp,Reached 107.173 U / mL,Bacillus cereus produces the highest cellulase activity,reaching 116.815 U / mL,Lactobacillus plantarum lipase activity of the highest,reaching 38.209 U / g.3 Optimization of technological conditions for multi-strain mixed fermentation of mulberry leavesThe best combination of the strains is determined as four strains: Trichoderma koningii,Candida albicans,Bacillus cereus and Lactobacillus plantarum by optimization of Fermentation Bacteria.The optimum inoculation amount is 5% and Bacillus cereus,Lactobacillus plantarum,Candida albicans,Trichoderma harzianum inoculation ratio of 2: 1: 1: 1;The best fermentation conditions that the optimal fermentation conditions are pH 7,fermentation time 84 h,fermentation temperature 30 ?were obtained by single factor test and orthogonal test.The content of crude protein was 36.30%,the content of true protein was 22.12% and the crude fiber content was reduced to 9.63% after fermengting the mulberry leaves under the optimum fermentation conditions.4 Degradation characteristics of mulberry leaves in rumen of beef cattleThe contents of common nutrients of mulberry and the real-time degradation rate and the effective degradation rate of dry matter(DM),organic matter(OM),crude protein(CP),neutral detergent fiber(NDF)and acid detergent fiber(ADF)in mulberry are measured in the rumen of beef cattle,respectively.6h,12 h,24h,36 h,48h,72 h.The results shows that the content of crude protein is 20.99%,the relative value of feed(RFV)reaches 2.22,and the roughing grade reaches the special level.The DM,CP and OM degradation rates of mulberry in the rumen of beef cattle are 87.62%,96.29% and 87.71% respectively,which are close to complete degradation.The effective degradation rate of each nutrient component is DM 68.38%,CP 74.60%,NDF 54.59%,ADF 15.04%,OM 68.51%,indicating that there is a high feed value in beef cattle on the mulberry.The degradation rate of mulberry leaves in the rumen was significantly increased in 36 h(P <0.05).After 36 h,the degradation rate decreased and the degradation rate became stable.Therefore,it can be considered that the nutrient content of mulberry is basically degraded in the rumen for 36 h,which shows that mulberry has the characteristics of rapid degradation in the rumen of beef cattle.