Engle T E, Spears J W, Fellner V, Odle J
Department of Animal Science and Interdepartmental Nutrition Program, North Carolina State University, Raleigh 27695-7621, USA.
J Anim Sci. 2000 Oct;78(10):2713-21. doi: 10.2527/2000.78102713x.
An experiment was conducted to determine the effects of Cu and soybean oil (SBO) supplementation on ruminal and tissue lipid metabolism and carcass characteristics in finishing steers. Sixty Angus steers (369.0 +/- 10.1 kg) were stratified by weight and randomly assigned to treatments in a 2 x 2 factorial arrangement, with factors being 0 or 20 mg of supplemental Cu/kg DM from Cu sulfate and 0 or 4% SBO. Steers were fed a high-concentrate basal diet that contained 5.3 mg Cu/kg DM. Average daily gain and feed intake were reduced (P < 0.01) by SBO but were not affected by Cu. Gain:feed ratio was not affected by treatment. Liver Cu concentrations were higher (P < 0.01) in steers receiving supplemental Cu and lower (P < 0.04) in SBO-supplemented steers. Copper supplementation tended to reduce (P < 0.12) and SBO supplementation tended to increase (P < 0.11) serum cholesterol concentrations. Backfat depth was reduced (P < 0.10) by Cu and SBO supplementation. Marbling scores and longissimus muscle lipid content were not affected by Cu supplementation; however, SBO supplementation reduced (P < 0.01) marbling scores. Longissimus muscle polyunsaturated fatty acids tended to be increased (P < 0.14) in Cu-supplemented steers. Longissimus muscle C18-conjugated dienes and the 18:1 trans isomer were increased (P < 0.05) in SBO-supplemented steers. Ruminal fluid 18:3 was increased (P < 0.05) and the 18:1 trans isomer was decreased (P < 0.05) in Cu-supplemented steers. These results indicate that as little as 20 mg of supplemental Cu/kg DM can reduce backfat and may alter lipid metabolism in steers fed high-concentrate diets.
进行了一项试验，以确定补充铜和大豆油（SBO）对育肥牛瘤胃和组织脂质代谢以及胴体特性的影响。60头安格斯牛（体重369.0±10.1千克）按体重分层，并随机分配到2×2析因设计的处理组中，因素分别为每千克干物质（DM）补充0或20毫克硫酸铜形式的铜，以及0或4%的SBO。给牛饲喂含5.3毫克铜/千克DM的高浓缩基础日粮。SBO降低了平均日增重和采食量（P<0.01），但不受铜的影响。料重比不受处理影响。补充铜的牛肝脏铜浓度较高（P<0.01），补充SBO的牛肝脏铜浓度较低（P<0.04）。补充铜有降低（P<0.12）血清胆固醇浓度的趋势，补充SBO有升高（P<0.11）血清胆固醇浓度的趋势。补充铜和SBO降低了背膘厚度（P<0.10）。大理石花纹评分和背最长肌脂质含量不受补充铜的影响；然而，补充SBO降低了大理石花纹评分（P<0.01）。补充铜的牛背最长肌多不饱和脂肪酸有增加的趋势（P<0.14）。补充SBO的牛背最长肌C18共轭二烯和18:1反式异构体增加（P<0.05）。补充铜的牛瘤胃液18:3增加（P<0.05），18:1反式异构体减少（P<0.05）。这些结果表明，每千克DM补充低至20毫克铜就能降低育肥牛的背膘，并可能改变其脂质代谢。
