两种洗涤处理对纤维饲料细胞壁组分和单糖组成变化的影响

采用连续和直接洗涤处理来分析高木质素、高易消化纤维和高果胶等3种类型牧草纤维和细胞壁单糖组成的变化。结果表明:连续洗涤的酸性洗涤纤维(ADF)和纤维素含量低于直接洗涤,半纤维素含量呈相反趋势(P<0.05),2种洗涤之间的酸性木质素含量无显著差异(P>0.05)。连续洗涤的高木质素类(小麦秸)、高易消化纤维类(大豆皮)和高果胶类饲料(苜蓿干草)的酸性洗涤残渣(ADR)中总单糖含量分别为37.54%、43.02%和34.01%,直接洗涤处理分别为40.92%、44.71%和37.74%。与直接洗涤相比,连续洗涤的ADR中半纤维素单糖含量低(P<0.05)。对2种洗涤的ADR进行单糖种类分析发现,木糖是主要的半纤维素细胞壁单糖污染。进一步研究发现,应用木聚糖酶能够部分消除木糖污染,提示半纤维素污染同时存在于2种洗涤的ADR中,但连续洗涤比直接洗涤所得的ADF结果更准确。

Effect of Two Detergent Methods in Van Soest Fibre Detergent System on Components of Fibre Fractious and Monosaccharide of Acid Detergent Residues in Fibrous Feedstuffs

A experiment was conducted to investigate the effect of the sequential and direct detergent methods in Van Soest fiber detergent system on the content of various fiber fractions and monosaccharide compositions of acid detergent residues(ADR) in three sources of fibrous feedstuffs.The three sources of fibrous feedstuffs were lignified,high digestible and high pectic ones,respectively.The results showed that contents of acid detergent fiber(ADF) and cellulose were lower for the sequential detergent method than those of the direct detergent method,while a contrary situation occurred with hemicellulose(HCE)(P<0.05).The content of acid detergent lignin(ADL) was similar between the two detergent methods(P>0.05).The total monosaccharide content found in the ADR varied between the two detergent methods.When the sequential detergent method was performed,the contents of total monosaccharides derived from ADR were 37.54%(lignified feedstuff),43.02%(high digestible feedstuff),and 34.01%(high pectic feedstuff) of the feedstuff DM,respectively.The corresponding results on ADR obtained from the direct detergent method were 40.92%(lignified feedstuff),44.71%(high digestible feedstuff),and 37.74 %(high pectic feedstuff),respectively.Compared with the direct detergent method,the sequential detergent method produced lower(P<0.05) percentages of remaining hemicellulosic contaminants of ADR,including xylose,mannose,arabinose and galactose.Xylanase was used to remove the contaminated xylose from ADR.It was found that xylanase partially removed the contaminated xylose in both detergent methods.Based on the present data,the sequential detergent method would be recommended in regular laboratory analysis of fiber in ruminant feedstuffs,because it is more effective to remove contaminated HCE sugar units than the direct detergent method.