【摘要】 为研究过瘤胃硫酸锌对肉牛瘤胃营养物质瘤胃降解率的影响,试验选用4头,24月龄,体重(513±5.7)kg的装有永久性瘤胃瘘管的晋南牛阉牛,采用4×4拉丁方试验设计,对照组日粮中添加300 mg锌(ZnSO47H2O),LRPZn、MRPZn和HRPZn组分别在日粮中添加200、300和400 mg的锌(过瘤胃硫酸锌,RPZn)。结果表明,玉米青贮干物质和有机物的有效降解率从高到低依次为HRPZn、MRPZn、LRPZn和对照组差异显著(P<0.05);中性洗涤纤维有效降解率HRPZn组显著高于其余各组(P<0.05)。混合精料干物质和有机物有效降解率HRPZn组显著高于对照组(P<0.05);粗蛋白质有效降解率HRPZn组显著高于对照组和LRPZn(P<0.05)。肉牛日粮中以过瘤胃硫酸锌形式添加400mg锌对提高日粮养分瘤胃降解率效果最佳。更多还原

【Abstract】 The effects of rumen-protected zinc(RPZn)supplementation on nutrient degradability of steers were studied.Four ruminally fistulated Jinnan beef steers(24 months of age and(513±5.7)kg of body weight)were used in a 4×4 Latin square experimental design.The treatments were:control(with 300 mg/d of zinc as ZnSO47 H2 O),low RPZn(LRPZn),medium RPZn(MRPZn)and high RPZn(HRPZn)with 200,300 and 400 mg/d of zinc as RPZn,respectively.The effective degradability(ED)of dry matter and organic matter in corn silage was the highest for HRPZn,followed by MRPZn and then LRPZn,and the lowest for control(P<0.05).The ED of neutral detergent fibre in corn silage was significantly higher for HRPZn compared with other groups(P<0.05).The ED of dry matter and organic matter in concentrate was significantly higher for HRPZn compared with control(P<0.05).The ED of crude protein in concentrate was significantly higher for HRPZn than for control and LRPZn(P<0.05).The results indicated that the optimum dose for improving nutrient degradability was 400 mg Zn as RPZn supplementation in steers.更多还原