Effects of dietary copper source and concentration on carcass characteristics and lipid and cholesterol metabolism in growing and finishing steers.
Effects of dietary copper source and concentration on carcass characteristics and lipid and cholesterol metabolism in growing and finishing steers.
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DOI：
10.2527/2000.7841053x
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发表时间：
2000-04
影响因子：
3.3
通讯作者：
T. Engle;J. Spears;T. A. Armstrong;C. Wright;J. Odle
中科院分区：
文献类型：
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作者：
T. Engle;J. Spears;T. A. Armstrong;C. Wright;J. Odle
本试验旨在研究饲粮铜（Cu）来源和水平对阉牛胴体特性、最长肌脂肪酸组成以及血清和肌肉胆固醇浓度的影响。60头安格斯和安格斯×赫里福德阉牛按体重和初始肝脏铜浓度进行分层，随机分配到不同处理组。处理包括：1)对照组（不添加Cu）；2)硫酸铜（CuSO4） 20 mg Cu/kg DM；3)从CuSO4中提取40 mg Cu/kg DM；4)从柠檬酸铜中提取20 mg Cu/kg DM；5)铜蛋白20 mg Cu/kg DM；6)从三碱式氯化铜中提取20 mg Cu/kg DM。以玉米青贮-豆粕为基础的饲粮饲喂56 d，然后转至高精料饲粮。在饲喂育肥期饲粮101或121 d后，每组屠宰同等数量（n = 5）的肉牛。生长期血清胆固醇不受处理影响，但在育肥期第84 d时，血清胆固醇水平降低（P < 0.05），并保持在较低水平（P < 0.05）。05)在随后的采样周期。铜有降低最长肌胆固醇浓度的趋势（P < .11）。添加Cu组热胴体重和背膘显著降低（P < 0.05）。然而，补铜组和对照组的大理石纹评分相似。最长肌多不饱和脂肪酸浓度（18:2和18:3）升高（P < 0.01），饱和脂肪酸浓度升高（P < 0.01）。11)通过补充铜来降低。由此可见，在高精料饲粮中添加20 mg Cu/kg即可降低肉牛背脂和血清胆固醇，增加肌肉多不饱和脂肪酸。
We conducted an experiment to determine the effects of dietary copper (Cu) source and level on carcass characteristics, longissimus muscle fatty acid composition, and serum and muscle cholesterol concentrations in steers. Sixty Angus and Angus x Hereford steers were stratified by weight and initial liver Cu concentration within a breed and randomly assigned to treatments. Treatments consisted of: 1) control (no supplemental Cu); 2) 20 mg Cu/kg DM from Cu sulfate (CuSO4); 3) 40 mg Cu/kg DM from CuSO4; 4) 20 mg Cu/kg DM from Cu citrate; 5) 20 mg Cu/kg DM from Cu proteinate; and 6) 20 mg Cu/kg DM from tribasic Cu chloride. A corn silage-soybean meal-based diet was fed for 56 d. Steers were then switched to a high-concentrate diet. Equal numbers (n = 5) of steers per treatment were slaughtered after receiving the finishing diets for either 101 or 121 d. Serum cholesterol was not affected by treatment during the growing phase but was decreased (P < .05) in steers supplemented with Cu by d 84 of the finishing period and remained lower (P < . 05) at subsequent sampling periods. Longissimus muscle cholesterol concentration tended to be reduced (P < .11) by Cu supplementation. Hot carcass weight and backfat were lower (P < .05) in animals receiving supplemental Cu. However, Cu-supplemented and control steers had similar marbling scores. Longissimus muscle polyunsaturated fatty acid concentrations (18:2 and 18:3) were increased (P < .07) and saturated fatty acid concentrations tended (P < . 11) to be reduced by Cu supplementation. These results indicate that as little as 20 mg of supplemental Cu/kg diet can reduce backfat and serum cholesterol and increase muscle polyunsaturated fatty acids in steers fed high-concentrate diets.