不同日粮对肉牛瘤胃可发酵有机物和全消化道有机物表观消化的影响

Effects of Dietary Intake on Rumen Fermentable Organic Matter and Organic Matter Total Tract Apparent Digestion in Steers Fed Varying Amounts of Concentrate

为了研究不同日粮有机物瘤胃发酵量与全消化道消化量之间的关系,选择体重600 kg左右的荷斯坦(Holstein)公牛3头,安装瘤胃、真胃瘘管,以三氧化二铬(Cr2O3)作真胃食糜标记物,全收粪法收集粪样,测定真胃食糜和粪中的有机物(OM)、中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)流量及在瘤胃内、全消化道的表观消化,分别以3×3拉丁方和2×3不完全拉丁方试验设计测定不同日粮有机物瘤胃发酵率和消化道表观消化率,试验Ⅰ为饲喂粗料进食量相同而精料进食量不同的3种日粮,试验Ⅱ为以豆粕、全脂大豆为蛋白质补充料来源的2种等蛋白日粮。结果表明:不同日粮对瘤胃及全消化道的OM、NDF、ADF表观消化率没有显著影响(P>0.05),但明显影响有机物瘤胃可发酵量(P<0.05);日粮有机物瘤胃表观发酵量(FOM,g/d)与日粮有机物全消化道消化量(DOM,g/d)有显著的相关关系:DOM(g/d)=1.27×FOM(g/d)+962.81(r2=0.95,n=5,P<0.01)。

An experiment was carried out to determine the relationship between the amount of dietary fermentable organic matter in tureen and the organic matter amount apparently digested in the total gastrointestinal tract of steers. Three Holstein steers （initial BW 600 kg） were used in a 3×3 latin square or a 2× 3 non-latin square to determine the influence of concentrate amount or protein supplementation on organic matter diges- tion. In Exp I , the three treatments were designed with different amount of grain-based concentrate （4,5, or 6 kg/d）. During Exp II, two iso-protein diets were designed with solvent-ex- tracted soybean meal and soybean respectively for 2 treatments. Steers fed hay and concentrate were adapted to diets for 15 d, followed by a 7d collection period. Digestibilities of organic matter, neutral and acid detergent fiber in the rumen and total tract were unaffected by different treatments （P〉0.05）. The results showed that the amount of OM to the abomasum and total tract in- creased with the amount of dietary organic matter.The prediction equation of organic matter apparently digested in the total gas- trointestinal tract （DOM,g/d） by rumen fermentable dietary organic matter （FOM,g/d） were：DOM （g/d）=l.27×FOM （g/d）＋ 962.81 （ r2=0.95, n=5, P〈0.01 ）.