甲醛处理对豆饼干物质和蛋白质瘤胃降解率及胃蛋白酶消化率的影响

Efect of Formaldehyde Levels on Soybean Dry Matter and Crude Protein Degradability in the Rumen and Digestibility in Pepsin Solution at different pH and Incubation Time

豆饼用２ｇ／ｋｇＤＭ甲醛处理后，１０ｈ瘤胃干物质（ＤＭ）降解率从８７．１９％下降到豆饼含水量为１４％的６０．９３％和含水量１８％时的５６．２９％，粗蛋白降解率从８７．６９％分别下降到４８．３６％和４３．４３％。随着甲醛用量的增加，干物质和粗蛋白的降解率可进一步下降，但下降幅度减少。在甲醛用量低于２ｇ／ｋｇＤＭ的情况下，甲醛用量对ｐＨ为４．５时的胃蛋白酶４ｈ和８ｈ干物质和粗蛋白消化率没有明显影响，但甲醛用量超过２ｇ／ｋｇＤＭ后，随着甲醛用量的增加，ｐＨ为４．５时的胃蛋白酶干物质和粗蛋白消化率呈直线下降。但是ｐＨ为１．５时的４ｈ和８ｈ胃蛋白酶干物质和粗蛋白消化率几乎不受甲醛用量的影响。

The dry matter(DM)degradability of soybean meal treated with 2g/kg DM formaldehyde for 10 hour incubation in the rumen decreases from 87.17% to 60.93%for 14% moisture soybean and 56.29% for 18% mositure soybean.The crude protein (CP) degredability decreases from 87.69% for untreated soybean to 48.36% and 43.43% for 14% and 18% moisture soybean meal treated with formaldehyde.The DM and CP degradability may further decrease as the level of formaldehyde increases.Soybean meal that treated with formaldehyde in excess of 2g/kg DM result in a marked reduction of DM and CP digestibility after incubation with pepsin at pH 4.5 for 4 and 8 hours.However,soybean meal incubated with pepsin-dyhychloric acid(pH=1.4)for 4 and 24 hours did not indicate any change in DM and CP digestibility with different amounts of formaldehyde.