Abstract
This experiment has following two aims. First one is to develope a rapid and simple enzymatic method for the determination of feed cell wall. Second one is to develope an enzymatic digestion method having a high accuracy in TDN prediction of hay and silage. Enzymes, source organisms were α-amylase (Bacillus subtilis), actynase E (protease from Streptomyces griseus), panchdase HP (protease from Aspergillus oryzae) and cellulase for feed analysis (Trichoderma reesei). The materials examined here as feed samples for cell wall determination were five corn silages, sorghum silage, barley, wheat bran and fecal samples when corn silages were fed. Potato starch and soybean meal were supplied as standard samples of starch and protein. Cell wall materials such as xylan, cellulose, isolated cell wall derived from grass and legume were also used to determine the cellulase and hemicellulase activity of enzymes. Furthermore, sixty five forages (hays and silages) were used to TDN prediction. Samples containing starch gelatinized firstly and then incubated with enzyme solution for 16 hr. at 40℃. Enzymatic system tried here were as follows ; 1) Two step method with α-amylase and actynase : At present, this method is used in Japan as ordinal enzymatic analysis of feeds. In this system, starch and protein digestion were carried out separetely. Therefore, two days need for analysis. 2) One step method with mixed enzymes : Sample was digested with enzyme mixture of 0.0025% (W/V) α-amylase and 0.025% (W/V) actynase. Enzymes were dissolved into pH5.8 acetate buffer solution containing 40ppm calcium acetate. 3) Panchdase-cellulase system : Sample was digested by 0.125% (W/V) panchdase and 1.0% (W/V) cellulase. Enzymes were disssolved into pH 4.4 acetate buffer solution. The main results obtained from these experiments were as follows : 1) In comparison of two step method and one step method concerning determined cell wall contents, there were no or slightly differences. And a time needed to analyze the cell wall was shorten by 24 hour by using a one step method. 2) High correlations were obtained between in vivo TDN and dry matter digestibility by panchdase and cellulase (DPC) in grass hays and grass-legume (alfalfa) mixed silages.
