Studies on the Improvement of Feeding Value of Structural Carbohydrate in Wood by Explosion Treatment

木材含有大量的结构性碳水化合物，可以被反刍动物消化。然而，纤维素和木质素之间的强键通常阻止其用作饲料。即木质化是降低木材消化率的一个主要因素，爆破法是一种有效的脱木质素方法，因为爆破法能使木质素和碳水化合物键断裂。此外，在爆破过程中，木质素有时会产生酚类单体。这种材料在普通饲料中找不到。因此，在实际使用爆破木材用于动物之前，必须研究这种材料对消化率和瘤胃发酵的影响。本试验研究了爆破处理对木材营养价值的影响及爆破木材作为饲料的可能性。爆破对细胞壁组分产生冲击，半纤维素含量降低，可溶性木质素含量增加。其他成分变化不大。爆炸样品的水提取物中检测到乙酸、糠醛和单糖。爆破处理对白杨和白色桦的影响显著。膨化白杨和白色桦树在处理后的体内消化率分别为42%和36%。在离体实验中，甲醇提取物的添加降低了淀粉和纤维素的消化。添加到酪蛋白中的MeOH对氨的产生没有明显的影响。甲醇抽提物的主要成分为降解木质素，分子量为1700-1900。降解木质素可能抑制瘤胃微生物的比活力。但是，由于活体试验表明，绵羊饲喂爆碎木材对VFA的产生没有影响，因此爆碎木材实际上可以用作反刍动物的饲料成分之一。

Wood contains a large amount of structural carbohydrate which can potentially be digested by ruminants. However, strong bond between cellulose and lignin usually prohibits its utilization as feed. That is, lignification in wood is a main factor in lowering digestibility of it. Explosion is known to be one of the effective way for delignification, since the lignin and carbohydrate bond can easily cleaved by this treatment. In addition, phenolic monomers are sometimes produced from lignin during explosion process. This material is not found in usual feed. Therefore, the effect of this material on digestibility and rumen fermentation has to be investigated prior to the practical use of exploded wood for animals. In this experimant, effect of explosion treatmtnt on nutritive value and possible usage of exploded wood as feed are investigated. The cell wall component was subject to umpact by the explosion, with decrease of hemicellulose content and increase of soluble lignin. The other compositions varied very little. Acetic acid, furfural and monosaccharides were detected in water extract of exploded samples. The explosion treatment had remarkable impact on poplar and white birch. Exploded poplar and white birch gave 42 and 36 percent in vivo digestibilities after the treatment. Addition of meoh extract resulted decrease of starch and cellulose digestion in the in vitro experiment. MeOH addition to casein did not have a clear effect on ammonia production. Major component of MeOH extract was degraded lignin, 1700-1900 of molecular weight. Degraded lignin by the treatment might inhibit specific activity of rumen microorganisms. However, since in vivo experiment showed that VFA production was not influenced by feeding exploded wood in sheep, exploded wood can practically be utilized as one of the feed ingredients for ruminants.