White C L, Cadwalader T K, Hoekstra W G, Pope A L
University of Wisconsin, Madison 53706.
J Anim Sci. 1989 Sep;67(9):2400-8. doi: 10.2527/jas1989.6792400x.
Four groups of three ram lambs were fed, in group pens, the following diets from 4 to 19 wk of age: 1) control (6 mg Cu/kg and 1 mg Mo/kg); 2) control plus 10 mg Cu/kg; 3) control plus 10 mg Mo/kg and 4) control plus 10 mg/kg of both Cu and Mo. Copper and Mo were added to the diet as copper sulfate and sodium molybdate. The main ingredients of the diets were alfalfa hay (20%), oats (20%) and corn (59%). At 19 wk, the animals were allocated randomly to individual metabolism cages and received a single oral dose of 75Se-selenomethionine. Liver Cu concentrations at slaughter (22 wk) were 77, 259, 68 and 316 mg/kg fresh weight for treatments 1 through 4. There was clinical evidence of Cu poisoning in lambs on treatment 2. Sheep given Cu supplements without additional Mo had reduced (P less than .05) levels of 75Se activity in muscle compared with control animals. This decrease in muscle 75Se in Cu-supplemented lambs was associated with a nonsignificant increase in 75Se content of other tissues and a nonsignificant increase in fecal excretion of 75Se. Apparent absorption and net retention of 75Se was 80% and 74%, respectively. Long-term ingestion of moderate levels of Cu influenced the metabolism of Se fed as selenomethionine, possibly through effects of chronic Cu toxicity on liver function.
四组每组三只公羊羔，在群体围栏中从4周龄到19周龄饲喂以下日粮：1）对照组（铜6毫克/千克，钼1毫克/千克）；2）对照组加10毫克铜/千克；3）对照组加10毫克钼/千克；4）对照组加10毫克铜/千克和10毫克钼/千克。铜和钼分别以硫酸铜和钼酸钠的形式添加到日粮中。日粮的主要成分是苜蓿干草（20%）、燕麦（20%）和玉米（59%）。在19周龄时，将动物随机分配到个体代谢笼中，并口服单剂量的75硒-硒代蛋氨酸。处理1至4的羔羊在屠宰时（22周）肝脏铜浓度分别为77、259、68和316毫克/千克鲜重。处理2的羔羊有铜中毒的临床证据。与对照动物相比，补充铜但未额外添加钼的绵羊肌肉中75硒活性水平降低（P<0.05）。补充铜的羔羊肌肉中75硒的减少与其他组织中75硒含量的非显著增加以及75硒粪便排泄的非显著增加有关。75硒的表观吸收率和净保留率分别为80%和74%。长期摄入中等水平的铜会影响以硒代蛋氨酸形式饲喂的硒的代谢，可能是由于慢性铜中毒对肝功能的影响。
