秸秆粗饲料中粗纤维结构层次的研究

通过酶解实验提出秸秆粗饲料中的粗纤维成分分为两个结构层次，即粗纤维中易被酶水解的是游离型半纤维素和纤维素，难以被酶水解的是与木质素键合的结合型半纤维素和纤维素。试验结果表明，棉花秸秆中半纤维素酶降解部分占半纤维素总量的80.98%，被纤维素酶降解部分占纤维素总量的19.31%；玉米秸秆中被半纤维素酶降解部分占半纤维素总量的60.23%，被纤维素酶降解部分占纤维素总量的44.36%；小麦秸秆中被半纤维素酶降解部分占半纤维素总量的46.20%，被纤维素酶降解部分占纤维素总量的43.04%；水稻秸秆中被半纤维素酶降解部分占半纤维素总量的47.60%，被纤维素酶降解部分占纤维素总量的51.80%。这可能是造成粗饲料消化代谢率低的主要原因。

Study on the Structural Layer of Crude Fiber in Roughage

The structural layer of crude fiber in the roughage of cereal was investigated by enzymatic hydrolysis. The crude fiber consists of two layers, i.e., the free type of cellulose and hemicellulose , it was easy to be hydrolyzed by enzyme ;and the combined type of cellulose and hemicellulose bonded to lignin, it was hard to be hydrolyzed by enzyme . It was found that the former was hydrolyzed by enzyme containing 80.98% of the total hemicellulose and containing 19.31% of the total cellulose in cotton stalk. That the former was hydrolyzed by enzyme containing 60.23% of the total hemicellulose and containing 44.36% of the total cellulose in maize stalk. That the former was hydrolyzed by enzyme containing 46.20% of the total hemicellulose and containing 43.04% of the total cellulose in wheat stalk. That the former was hydrolyzed by enzyme containing 47.60% of the total hemicellulose and containing 51.80% of the total cellulose in rice stalk. It suggests that this is could be the main reason for lower ratio of digestibility and metabolism of roughage.