为了研究日粮营养水平(精料进食水平)对肉牛日粮消化能和粪能排出量的影响,试验选用体况良好、体重一致(347 kg±25 kg)的杂交后备母牛(西门塔尔牛(♂)×中国黄牛(♀))16头,随机分为4组,即处理Ⅰ组、Ⅱ组、Ⅲ组和Ⅳ组,每组4头,各试验组日粮精料进食量分别为1.5、2.5、3.5和4.5 kg,粗料(青贮)自由采食.总试验期为30 d,预饲期20d后进入正试期,试验期最后7 d全收集粪样.结果表明:不同日粮处理间全消化道蛋白质、淀粉的表观消化量和日粮消化能有显著差异(P＜0.05),并随日粮营养水平(精料进食水平)的增加而增加,但不同日粮处理间中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的表现可消化量没有差异,粪中能量的排出量也没有明显差异(P＞0.05).日粮可消化有机物与消化能的进食量呈直线强相关,即消化能DE(MJ/d)=0.669+18.476 DOM(kg/d)(R2=0.999 6,n=4).%The objective of this study was to determine the effect of dietary nutrient intake on the digestible energy. Four dietary treatments were designed in a 4 × 4 factorial arrangement. Heifers were allotted by the following dietary treatments: ①1.5 kg concentrate; ②2.5 kg concentrate; ③3.5 kg concentrate; ④4.5 kg concentrate. All feces were collected using the direct collection during the last week. The results showed that apparent digestible organic matter, protein, starch and digestible energy were significantly different (P＜0.05) among the different treatments. The excretion of fecal energy has no significant differences among different nutrient intakes (P＞0.05). As the digestible organic matter increased, the digestible energy linearly increased(P＜0.01 ), the regression equation was DE( MJ/d )=0.669+ 18.476 DOM(kg/d).
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