Evaluation And Application On Nutrition Value Of Straws By Ruminal Simulation System

The aim of this study wasto investigate the distribution of corn,rice,and wheat straws in China,according to the actual planting conditions of these three kinds of cereal crops.The chemical compositions of different straws from different provinces were evaluated,to analyze the differences among samples Crop straws,as "low energy feed",were feed to dry cows,for the evaluation of their application.The in vitro digestibility of different types of crop straws(single or combination)and abundances of ruminalcellulytic bacteria were evaluated,using artificial rumen simulation system.In addition,the addition of cellulolytic enzyme were also evaluated using the same system.The results could support the effective utilization of corn,rice and wheat straws in different regions of China,and also support the feasibility of straw fodder as "low energy feed" to dry cows.Specific research contents were as follows:Experiment 1.The aim of this experimrnt was to investigate the distribution of corn,rice,and wheat straws in 15 different provinces in China.Henan,Sichuan,Hubei,Jiangsu,and Ansu provinces were the top five that owned the most resources of these three crop straws.Based on the chemical compositions of corn,rice and wheat straws from the five provinces mentioned bove,corn and rice straws were better than wheal straw,and they did not influcended by territory.For wheal straw,its nutritive value was better in Henan province than other provincesExperiment 2.The aim of this experimrnt was to study the in vitro digestibility of different types of crop straws(single or combination),using artificial rumen simulation system.There were 6 treatment:corn straw group,rice straw group,wheat straw group,50%corn straw+50%rice straw group,50%corn straw+50%wheat straw group and 50%rice straw+50%wheat straw group.The experimental period lasted 14days.Results showed that the digestibility of corn straw was better than wheat and rice straws,and the MCP concentration of 50%corn straw+50%rice straw group and 50%rice straw+50%wheat straw group were higherExperiment 3.The aim of this experiment was to investigate effects of different types of crop straws(single or combination)on the population of rumen cellulolytic bacteria.The in vitro fermentation was done using artificial rumen system,and the experimental design was the same as Experiment 2.Results showed that the population of these rumen cellulolytic bacteria varied among different straw and different straw combination.The population of Ruminococcusalbus and Ruminococcusflavefaciens were higher in the Wheat straw group,while the population of Fibrobactersuccinogenesand Ehrlichiaruminantiumwere higher in the straw combination group,especially in the 50%corn straw+50%rice straw group and in the 50%rice straw+50%wheat straw group.In summary,as different straw has different fiber structure,the rumen cellulolytic bacteria have different ability for degrading these different straws.Experiment 4.The aim of this experiment was to evaluate the effect of compound anzymesupplementation on the in vitro digestibility of different types of crop straws(single or combination).There were 3 treatments:1)50%corn straw+50%rice straw+enzyme;2)50%corn straw+50%wheat straw+enzyme;3)rice straw+enzyme;The experimental period consisted of 3 days for adaptation and 3days for sampling.Results showed that,comparing with the results of experiment 2(without anzymesupplementation),supplementation of anzymein the diet increased the concentration of VFAs and amount of protozoain the fermentation fluid,but decreased pH and the concentration of NH3-N.In addition,supplementation of compound anzyme also increased the digestibility of dry matter and neutral detergent fiber.Experiment 5.The aim of this experimrnt was to evaluate the effect of crop straws as "low energy feed"on dry cows.32 of Holstein dry cows were randomly enrolled into four treatment groups,and feed corn straws(CS),50%corn straw+50%rice straw(CS+RS),50%rice straw+50%wheat straw(RS+WS)and oat grass as control(CK),respectively.Results showed that there was no significant differences on dry matter intake and milk production among treatments.Both milk composition and disease incidence were not influenced by the supplementation of crop straws.In summary,the nutritive value of corn and rice straws were better than wheat straw,and they did not influcended by territory.Different types of crop straws(single or combination)all have effect on the population of rumen cellulolytic bacteria.Supplementation of compound anzyme also increased the digestibility of dry matter and neutral detergent fiber.In addition,three crop straws could be used as forage sources instead of oats grass in dry cow diets.