National Institute of Animal Nutrition and Physiology, Adugodi, Bangalore 560030, India.
J Trace Elem Med Biol. 2010 Apr;24(2):89-94. doi: 10.1016/j.jtemb.2009.11.007. Epub 2010 Jan 13.
The effect of feeding Cu- and Zn-methionine to ewes was studied in a 240d feeding trial. The plasma and tissue Cu and Zn concentrations and Cu/Zn-superoxide dismutase (Cu/Zn-SOD) activity were employed to assess the relative bioavailability from Cu- and Zn-methionine. The macro and micronutrient intake, utilization, plasma mineral status, tissue accumulation of Cu and Zn as well as wool concentration of Cu and Zn were studied in ewes (n=12) fed a corn-soybean meal based basal diet with 50% more Cu and Zn supplementation over the basal diet either from Cu- and Zn-sulfate (Cu-Sulf+Zn-Sulf group) or Cu- and Zn-methionine (Cu-Meth+Zn-Meth group). The average daily feed intake and body weight gain of ewes did not differ due to dietary supplementation of Cu- and Zn-methionine. However, dry matter intake was comparatively lower and thus resulted in better feed: gain in Cu- and Zn-methionine group as compared to ewes fed Cu- and Zn-sulfate. Supplementation of Cu and Zn over the basal diet either from methionine-chelated or sulfate sources resulted in increased plasma Cu and Zn as well as Cu/Zn-SOD activity on d-30, which indicated a positive correlation between plasma Cu and Zn and Cu/Zn-SOD activity. The gut absorption, liver concentrations of Cu and Zn, and liver Cu/Zn-SOD activity were significantly (P<0.01) higher in ewes supplemented with Cu- and Zn-methionine compared to Cu- and Zn-sulfate. Periodical analysis of wool samples indicated no significant difference in Cu and Zn content between Cu-and Zn-methionine and Cu- and Zn-sulfate groups. Feeding of Cu and Zn from methionine-chelated source resulted in reduced (P<0.01) excretion of Cu and Zn in feces indicating their better utilization, and this will have positive implication on environment. The gut absorption values, plasma and liver tissue concentrations of Cu and Zn supported the hypothesis that Cu- and Zn-methionine supplements have better bioavailability compared to Cu- and Zn-sulfate and Cu- and Zn-dependent enzyme (Cu/Zn-SOD) could be used to determine the bioavailability of Cu and Zn.
在一项为期 240 天的饲养试验中，研究了向母羊投喂铜和锌蛋氨酸的效果。利用血浆和组织铜和锌浓度以及铜/锌超氧化物歧化酶（Cu/Zn-SOD）活性来评估铜和锌蛋氨酸的相对生物利用度。在以玉米-豆粕为基础的基础日粮中，用 50%的基础日粮补充铜和锌，用铜和锌硫酸盐（Cu-Sulf+Zn-Sulf 组）或铜和锌蛋氨酸（Cu-Meth+Zn-Meth 组）补充，研究了母羊的宏量和微量营养素摄入、利用率、血浆矿物质状况、铜和锌在组织中的积累以及羊毛中的铜和锌浓度。由于日粮中补充了铜和锌蛋氨酸，母羊的日均采食量和体重增重没有差异。然而，由于干物质摄入量较低，因此与饲喂铜和锌硫酸盐的母羊相比，铜和锌蛋氨酸组的饲料/增重比更好。无论从蛋氨酸螯合还是硫酸盐来源补充铜和锌都可以在第 30 天增加血浆铜和锌以及 Cu/Zn-SOD 活性，这表明血浆铜和锌与 Cu/Zn-SOD 活性之间存在正相关。与补充铜和锌硫酸盐的母羊相比，补充铜和锌蛋氨酸的母羊的肠道吸收、肝脏铜和锌浓度以及肝脏 Cu/Zn-SOD 活性显著（P<0.01）更高。定期分析羊毛样本表明，铜和锌蛋氨酸组与铜和锌硫酸盐组之间的铜和锌含量没有显著差异。从蛋氨酸螯合来源补充铜和锌会导致粪便中铜和锌的排泄量减少（P<0.01），表明其利用率更高，这对环境有积极影响。肠道吸收值、血浆和肝脏组织中铜和锌的浓度支持了这样的假设，即与铜和锌硫酸盐相比，铜和锌蛋氨酸补充剂具有更好的生物利用度，并且铜和锌依赖性酶（Cu/Zn-SOD）可用于确定铜和锌的生物利用度。
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