稻草和精料及非蛋白氮对水牛瘤胃纤维素酶活力的影响

Change of Cellulase Activity Induced by Supplemented with Concentrate and Non-protein Nitrogen to Rice Straw Based Diet Fed to Water Buffalo

试验用 3头安装永久性瘤胃瘘管的成年水牛。采用自身对照方式在不同日粮条件下分别测定了瘤胃液内纤维素酶 (CMCase和FPase)活力以及厌氧真菌孢子数量。试验分为 4期 :稻草期 (Ⅰ期 ) ,稻草 +精料期 (Ⅱ期 ) ,稻草、精料 +羟甲基尿素期 (Ⅲ期 )和稻草、精料、羟甲基尿素 +硫酸铵期 (Ⅳ期 ) ,每期 2 0d。Ⅱ期稻草添喂精料 (2kg/d)时CMCase和Fpase平均活力分别下降 39% (P <0 .0 1)和 11% (P <0 .0 5 ) ;Ⅲ期加入羟甲基尿素 (80 g/d)CM Case和Fpase平均活力比Ⅱ期上升 89% (P <0 .0 1)和 19(P <0 .0 5 ) ,且显著高于Ⅰ期 (P <0 .0 5 )。Ⅳ期饲喂稻草、精料、羟甲基尿素 +硫酸铵 ,FPase活力比Ⅲ期进一步提高 (9% ,P <0 .0 5 )。Ⅰ、Ⅱ、Ⅲ期之间真菌孢子数量没有显著差异 ,Ⅳ期显著低于其它 3期 (P <0 .0 5 )。结果表明稻草基础日粮添加淀粉等非结构多糖时加入羟甲基尿素和硫酸铵显著提高瘤胃微生物纤维素酶活性。

adult water buffalo with fixed fistula in rumen were f ed: rice straw based diet (R, Period Ⅰ), R supplemented with 2 kg/d concentrate (R+C, Period Ⅱ), R+C + urea 80 g/d (RCU, Period Ⅲ) and RCU + 14 g/d (NH 4 ) 2SO 4 (RCUS, Period Ⅳ). Each period was lasted for 20 d. At the e nd of each period the CMCase (Carboxymethyl cellulase) and FPase activity (The f ilter paper assay), and the rumen anaerobic fungal spore number in rumen fluid w ere determined to evaluate the effects of these three added nutrients on ruminal cellulase activity. Supplemented concentrate to R, in Period Ⅱ,caused the decr eases of CMCase and FPase activity by 39%(P<0.01) and 11% (P<0.05), respectively. In Period Ⅲ, CMCase and FPase activity dramatically enhanced by 8 9%(P<0.01)and 19%(P<0.05) than those in Period Ⅱand by 36%(P <0.01) and 11%(P<0.01) than those in period Ⅰ due to added urea to R+ C (R+C+U). Additional intake of (NH 4) 2SO 4(RCUS) by wat er buffalo in Period Ⅳ resulted in a further increase of FPase activity by 9% (P<0.05) following significant stimulating effect of urea in Period Ⅲ. H owever, fungal spores neither change in Period Ⅱ nor in Period Ⅲ. It reduced s ignificantly in Period Ⅳ. The results of this study show that dietary nutrients of carbon, nitrogen, non-protein nitrogen (urea) and sulfate are of importance to ruminal crude fiber digestion. Supplement of non-structure starch and urea and sulfate synchronously to basal diet of rice straw intake by water buffalo in creases ruminal cellulose degradation.