Study On Combination Optimization Of Corn Straw Treated By CaO And Its Effect On Fiber Component,Molecular Structure And In Vitro Gas Production Rate In Rumen

This study aims to different concentrations of calcium oxide（CaO）dealing with different moisture content of corn straw samples,analysis of the molecular structure of the secondary components of corn stalk fiber and the effects of rumen in vitro gas rate,screening for feeding ruminant maize straw best CaO treatment combination and explore CaO change effect of corn straw stalk fiber structure.The specific research is divided into the following four parts:（1）X ray fluorescence method（XRF）was used to analyze the adhesion degree of CaO and Ca in corn straw treated by different treatment groups,and AOAC method was used to analyze the changes of fiber components of corn straw treated by CaO.（2）the changes of surface structure of corn straw were observed by using scanning electron microscope（SEM）.（3）ATR-FT/IR was used to determine the spectrum of corn straw at 4000-800cm^-1 band and analyze the molecular structure characteristics of carbohydrates in the spectrum;（4）in vitro gas yield method was used to analyze the variation law of in vitro gas yield and gas yield rate of corn straw treated with different CaO ratio.In this study,two factors were used to treat corn stalks with humidity of 40%,50%,60%and moisture with 0%,3%,5%and 7%CaO.Experiment 1:The analysis of the treatment effect of CaO on corn stalk and the influence of CaO on the fiber composition of corn stalk in each treatment group.The results show that:（1）the compacted sealed anaerobically preserved corn straw after treatment can solve the problem that corn straw is easy to mold and agglomerate after treated with CaO alkali treatment;（2）each component of corn stalk fiber decreased after CaO alkali treatment with different proportions,and the relationship between the content change of each component and CaO addition ratio was 0%>3%>5%>7%of the trend.Experiment 2:The effects of different combinations of corn straw treated by CaO on the fiber structure of corn straw were studied.The changes of lignocellulosic structure of corn stalk treated with different proportions of CaO were observed and analyzed by the combination of XRF,SEM and ATR-FT/IR.The results show that:（1）According to the analysis of the adhesion degree of CaO and Ca on the surface of corn stalk by XRF,the three groups were the best:5%×60%,7%,×40%and 7%×50%.（2）SEM observed that 5%×50%,5%×60%,7%×60%of the three corn straw treatment groups had a large number of changes in the surface long tube structure.The surface layer of corn straw was no longer smooth and became uneven,with obvious collapse,obvious lamellar structure and a large number of debris（3）ATR-FT/IR was used to detect and analyze the differences in the internal structure of corn stalk carbohydrates in different treatment groups.7%×40%were significantly higher in the treatment group than in the other treatment groups（P<0.05）.CaO treatment had a significant effect on the peak height of lignin in corn straw,the peak height and peak area of cellulose compound and the peak area of CHO peak 1（P<0.01）;The peak area of corn stalk lignin,the peak height of CHO peak 1,CHO peak height of CHO peak 2 and CHO peak area of CHO peak 3 were all significantly affected.（4）The NDF of corn straw in CaO treatment group was positively correlated with the peak height of lignin,the peak peak area of fiber composite and the peak peak area of three sub-peaks of CHO.The peak height of ADF of corn straw in different proportions of CaO treatment group was positively correlated with the peak height of the second sub-peak of CHO（P<0.05）,there was no significant correlation among the remaining secondary molecular structures with corn straw.Experiment 3:Using different time point in vitro gas production in vitro analysis of different proportions of corn stover treated CaO the change of the rate of producing gas,find different proportion CaO corn straw in 6,12,24,48,72h in vitro gas production all have significant differences,and along with the increase of CaO addition amount,in vitro gas production rate significantly increased,and gas production in vitro and in vitro gas rate are7%>5%>3%>0%.Conclusion:it can be concluded that the destruction of lignocellulose structure of corn straw after CaO treatment exposes the part of corn straw which is easy to be digested and absorbed by ruminant microorganisms,and changes the structure of corn straw,and increases the digestibility in ruminants.The two proportions of 5%and 7%were better treated with CaO,which provided theoretical and technical support for the alkali treatment of corn straw as ruminant animal feed in practice production.Through the comprehensive analysis of XRF,SEM and ATR-FT/IR techniques,it is concluded that 5%×60%of the corn stalk treatment group is the optimal treatment combination.