6种饲料原料瘤胃降解特性和瘤胃非降解蛋白质的小肠消化率

本试验旨在研究新疆地区玉米青贮、棉籽壳、苜蓿草粉、苜蓿干草、葡萄籽粕、蕃茄酱渣6种奶牛饲料原料的瘤胃降解特性和瘤胃非降解蛋白质(RUP)的小肠消化率(Idg)。选用3头装有永久性瘤胃瘘管的泌乳荷斯坦奶牛,采用尼龙袋法和改进三步体外法测定饲料原料的干物质(DM)、粗蛋白质(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的瘤胃降解特性以及RUP的Idg和小肠可消化粗蛋白质(IDCP)含量。结果表明:1)苜蓿草粉和玉米青贮的DM有效降解率最高,显著高于次之的苜蓿干草、番茄酱渣(P0.05),葡萄籽粕、棉籽壳最低,显著低于其他原料(P0.05);CP有效降解率为番茄酱渣苜蓿草粉玉米青贮苜蓿干草棉籽壳葡萄籽粕,各原料间差异显著(P0.05);NDF有效降解率为玉米青贮苜蓿草粉棉籽壳苜蓿干草番茄酱渣葡萄籽粕,各组饲料原料间差异显著(P0.05);ADF有效降解率为玉米青贮棉籽壳苜蓿干草番茄酱渣苜蓿草粉葡萄籽粕,各组饲料原料间差异显著(P0.05)。2)苜蓿草粉RUP的Idg和IDCP含量最高,Idg显著高于依次降低的苜蓿干草、玉米青贮、番茄酱渣、葡萄籽粕、棉籽壳(P0.05),IDCP含量与苜蓿干草差异不显著(P0.05),显著高于依次降低的玉米青贮、番茄酱渣、葡萄籽粕、棉籽壳(P0.05)。综上所述,不同饲料原料具有不同的瘤胃降解特性,进入小肠IDCP的含量也不同。玉米青贮的DM、NDF和ADF在瘤胃的有效降解率较高,苜蓿草粉RUP的Idg较高,苜蓿草粉和苜蓿干草的IDCP含量较高。

Ruminal Degradation Characteristics and Small Intestinal Digestibility of Rumen Undegraded Protein of Six Feed Ingredients

This experiment was conducted to determine the ruminal degradation characteristics and small intestinal digestibility of rumen undegraded protein (RUP) of six feed ingredients for dairy cows from Xinjiang, including corn silage, cottonseed hulls, alfalfa meal, alfalfa hay, grape seed meal and tomato sauce residue.Three lactating Holstein cows fitted with permanent rumen fistulas were selected to estimate the ruminal degradation characteristics of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) and small intestinal digestibility and intestinal digestible crude protein (IDCP) content of RUP by nylon-bag technique and modified three-step in vitro method.The results showed as follows:1) DM effective degradability of alfalfa meal and corn silage was higher, which was significantly higher than that of alfalfa hay and tomato sauce residue (P<0.05), and DM effective degradability of grape seed meal and cottonseed hulls was significantly lower than that of the other feed ingredients (P<0.05);CP effective degradability showed tomato sauce residue > alfalfa meal > corn silage > alfalfa hay > cottonseed hulls > grape seed meal with significant differences among feed ingredients (P<0.05);NDF effective degradability showed corn silage > alfalfa meal > cottonseed hulls > alfalfa hay > tomato sauce residue > grape seed meal, and the differences among feed ingredients were significant (P<0.05);ADF effective degradability showed corn silage > cottonseed hulls > alfalfa hay > tomato sauce residue > alfalfa meal > grape seed meal with significant differences among feed ingredients (P<0.05).2) Small intestinal digestibility and IDCP content of RUP of alfalfa meal were the highest;small intestinal digestibility of alfalfa meal was significantly higher than that of alfalfa hay, corn silage, tomato sauce residue, grape seed meal and cottonseed hulls (P<0.05), which was decreased in order;there was no significant difference of IDCP content of RUP between alfalfa meal and alfalfa hay, which was significantly higher than that of corn silage, tomato sauce residue, grape seed meal and cottonseed hulls (decreased in order) (P<0.05).In conclusion, different feed ingredients have different ruminal degradation characteristics and the efficiency of IDCP production.Effective degradability of DM, NDF and ADF of corn silage is higher, small intestinal digestibility of RUP of corn silage was the highest, and alfalfa meal and alfalfa hay have higher IDCP content.