Study On Lignocellulose Degradation Of Roughages With Different Lignin Composition In Buffalo Rumen

Lignin,which is composed of 3 monomer including guaiacyl,syringyl and p-hydroxyphenyl,is the most difficult component to be degraded of feedstuff and lignin composition is an important factor affecting lignin degradation.Buffalo is one of the few animal which is able to digest feed lignin.This study has determined quantity parameters of G?mg/g?,S?mg/g?,H?mg/g?and G+S+H?mg/g?and ratio parameters of S/G,H/G,H/S,G/?G+S+H?,S/?G+S+H?,H/?G+S+H?of all of 8 roughages including rice husk,DDGS,silage corn stover,rice straw,peanut vine,corn stover,bractea and sweet potato vine though Py-GC-MS method,then lignin composition together with lignin content,which made up lignin unique parameters,were processed by correlation analysis with in vivo nylon bag experiment results including DMD,NDFD,ADFD,CELD,HCD,ADLD and in vitro fermentation results including IVDMD,GP?ml/g?,CH₄?ml/g?,CO₂?ml/g?,VFA?mmol/L?,acetic acid?mmol/L?,propionic acid?mmol/L?,butyric acid?mmol/L?and acetic/propionic value.The prediction models were built by multiple linear regression method finally based on correlation ship data to access the effect of lignin characterization on digestibility of crude fiber in buffalo rumen.The results showed that:?1?H/S value of feeds lignin is negative to feeds DMD in vivo and S,S/G and S/?G+S+H? are positive to DMD.The multiple linear regression equation is expressed as DMD=0.405+1.072*S/G-0.036*H/S,?R²=0.753,P<0.01?.?2?H/S value of feeds lignin is negative to feeds NDFD and S,S/G and S/?G+S+H?are positive to NDFD.The multiple linear regression equation is expressed as NDFD=0.647-0.071*H/S,?R²=0.628,P<0.01?.?3?H/S value of feeds lignin is negative to feeds ADFD and S,S/G and S/?G+S+H?are positive to ADFD.The multiple linear regression equation is expressed as ADF=0.427+0.826*S/G-0.045*H/S,?R²=0.678,P<0.01?.?4?H,H/S,H/G and H/?G+S+H?value of feeds are proved to be negative to feeds ADLD and S and S/?G+S+H?are positive to ADLD.The multiple linear regression equation is expressed as ADLD=0.161-1.918*H+3.152*S,?R²=0.758,P<0.01?.?5?S/?G+S+H?value of feeds is positive to all of VFA,acetic acid,propionic acid and butyric acid concentration respectively.The multiple linear regression equation is expressed as VFA=4.787+510.299*S/?G+S+H?-1423.775*S+2.18*H/S,?R²=0.940,P<0.01?,Acetic acid=12.635+128.632*S/?G+S+H?,?R²=0.848,P<0.01?,Propionic acid=3.884+126.039*S/?G+S+H?-514.463*S,?R²=0.920,P<0.01?and Butyric acid=2.151+32.145*S/?G+S+H?,?R²=0.881,P<0.01?respectively.Conclusion:Among the 8 roughages of this study,when the H/S value higher,the rumen digestibility of dry matter and fiber component is lower according to?1??2??3?;when the H monomer content higher,the rumen digestibility of lignin is lower and when the S monomer content higher,the rumen digestibility of lignin is higher according to?4?;when the S/?G+S+H?value higher,the concentration of VFA,acetic acid,propionic acid and butyric acid is higher according to?5?.