Research On The Effect Of Storage Modes On Feeding Value Of Rice Straw Before And After Steam Explosion Treatment

The fact that Chinese plough,accounting for only 7%of the world’s,feeded Chinese,accounting for 22%of the world’s,contributed to the food security problems.In recent years,with the improvement of people’s living standard,the people’s demand for meat,eggs,milk and other food continued to grow.However,a lack of forage resources in our country brought about food fight and plough fight between people and livestock.Meanwhile,straw was an important biomass resource in the world,with an annual output of about 4 billion tons.Each year in China there was about 820 million tons crop straw,of which 215 million tons crop straw was thrown away or incinerated,which not only wasted of resources but also caused serious air pollution;The production of straw into a high-quality feed for livestock to eat can be converted to people’s daily food,such as meat,eggs,milk and so on.Not only was resource saved,the environment protected but also the problem of food security was eased.Due to straw,substituted for forage as feed,contained the high content of lignin and also lignin enveloped cellulose at position in space,its nutritional value was only half of hay’s,although its total energy was close to the hay’s.Steam explosion technology could effectively degrade fiber in straw,especially could significantly undermine the effect of lignin enveloping cellulose at position in space,so that both the intake and absorption of straw for ruminants had been greatly improved.Based on the in-depth review of relevant literature at home and abroad and Li Bin et al’s first use of steam explosion processing to treat rice straw as feed,on the purpose of increasing enzymatic hydrolysis sugar yield,the existing steam explosion process was optimized.The scheme was proposed that the constant pressure maintaining in the steam explosion process was divided into two stages,holding pressure cooking and quickly increasing steam pressure before blasting,and steam pressure of the two stages was respectively controlled.Three factors,cooking pressure under stable pressure(A/MPa),cooking time under stable pressure(B/s)and pressure before blasting(C/MPa),on enzymatic hydrolysis sugar yield(D/%)of rice straw were studied by response surface methodology.Rice straw was stored by open-air storage,shed storage,silage,wilted silage and ammoniated storage.The impact of different storage ways of rice straw on feeding value before pretreated by steam explosion with storage time changing was studied.Also the impact of different storage ways of rice straw on feeding value after pretreated by steam explosion with storage time changing was studied.The main results are as follows:(1)Test of optimizing steam explosion pretreatment process of rice straw.The results showed that:A,B and C influence the D significantly.With the increase of A and C,D increases significantly;with the increase of B,D increases.When A is 1.6 MPa,B is 140 s,and C is 2.2 MPa,D,the highest,is 37.48%,which is 1.87 times that of the before steam explosion processing.Obviously enzymatic hydrolysis sugar yield was improved by improving and optimizing steam explosion processing technology.(2)Test of the impact of different storage ways of rice straw on feeding value before pretreated by steam explosion with storage time changing The results showed that:the best storage of rice straw is ammoniated storage,then is silage,then is wilted silage,then is shed storage and the worst is open-air storage;at the same time,the change of rice straw feeding value occurred mainly in the early storage.(3)Test of the impact of different storage ways of rice straw on feeding value after pretreated by steam explosion with storage time changing The results showed that:the shape of rice straw in silage and wilted silage,after pretreated by steam explosion,was no more complete and almost powder,so that rice straw was no longer suitable for ruminant animals to eat;all aspects of the indicators of rice straw in wilted silage,after pretreated by steam explosion,were better than that of rice straw in shed storage,and all aspects of the indicators of rice straw in shed storage,after pretreated by steam explosion,were better than that of rice straw in open-air storage;rice straw in wilted silage helped to strengthen the steam explosion to improve the reducing sugar yield.