本试验旨在探究不同水平的微量元素对陕北白绒山羊断奶羔羊生产性能、营养物质消化代谢和组织中微量元素沉积量的影响.选择6月龄、体重约为20 kg的陕北白绒山羊24只,随机分为4组,每组3个重复,每个重复2只羊.各组分别添加不同水平的微量元素,Ⅰ组饲粮铁、铜、锌、锰、钴含量分别为279.30、15.35、63.41、68.51、0.22 mg/kg,Ⅱ组分别为290.14、18.19、81.62、94.10 mg/kg,Ⅲ组分别为302.23、28.20、103.28、133.85、0.43 mg/kg,Ⅳ组分别为319.74、31.60、126.64、167.07、0.67 mg/kg.饲养试验共65 d,其中预试期5 d,正试期60 d.饲养试验正试期第30天,从每个重复中随机挑选1只羊,共12只,分别放入单独的代谢笼中进行消化代谢试验.预试期7d,正试期7d.饲养试验最后1d,将剩余的12只羊屠宰,采集羊的心脏、肝脏、脾脏、肾脏及背最长肌,测定微量元素沉积量.结果表明:1)Ⅱ组平均日增重、料重比分别显著高于、低于Ⅰ组(P<0.05),与Ⅲ、Ⅳ组差异不显著(P>0.05);Ⅱ组干物质采食量显著高于其他组(P<0.05).2)Ⅰ、Ⅱ组粪能、尿能显著低于Ⅲ、Ⅳ组(P<0.05),总能消化率显著高于Ⅲ、Ⅳ组(P<0.05).3)Ⅲ组氮沉积率、进食氮、可消化氮、沉积氮最高,显著高于Ⅰ、Ⅳ组(P<0.05),与Ⅱ组差异不显著(P>0.05).4)各微量元素表观代谢率随微量元素添加水平升高呈先增加后减少趋势,Ⅱ组铜、铁、锰、锌、钴表观代谢率最高.5)Ⅱ组背最长肌、心脏的锰沉积量最高,肝脏铁、碘、铜、锰沉积量最高;在脾脏中,Ⅱ组铁沉积量最高,Ⅳ组碘沉积量最高;在肾脏中,Ⅱ组锌沉积量最高,Ⅰ组碘沉积量最高.在本试验条件下,陕北白绒山羊微量元素需要量的最佳组合为:铁290.14 mg/kg、铜18.19 mg/kg、锌81.62 mg/kg、锰94.10 mg/kg、钴0.31 mg/kg.%This study was conducted to evaluate effects of different levels of dietary trace elements on perform-ance, nutrients digestion and metabolism, trace element deposition in tissues of weaned lambs of Shaanbei white cashmere goats. Twenty-four 6-month old weaned lambs of Shaanbei cashmere goats with about 20 kg of body weight were selected and randomly assigned to four groups, each group had three replicates, and each replicate had 2 lambs. The goats in different groups were fed diets containing different trace elements levels. In group Ⅰ, iron, copper, zinc, manganese and cobalt contents in diet were 279.30,15.35,63.41,68.51 and 0.22 mg/kg, respectively,in groupⅡ,those were 290.14,18.19,81.62 and 94.10 mg/kg,respectively,in group Ⅲ, those were 302.23, 28.20, 103.28, 133.85 and 0.43 mg/kg, respectively, in group Ⅳ, those were 319.74,31.60,126.64,167.07 and 0.67 mg/kg, respectively. The feeding trial lasted for 65 d inclu-ding 5 d of pre-test period and 60 d of test period. On day 30 of test period in feeding trial, one lamb from each repeat was selected and fed individually in cage to carry out digestion and metabolism test. The pre-test pe-riod was 7 d, and the test was 7 d. At the last day of feeding trial, the rest 12 lambs were slaughtered to col-lected heart, liver, spleen, kidney and the longissimus dorsi, and trace element deposition were determined. The results showed as follows:1)average daily gain and feed to gain ratio in group Ⅱ were significantly high-er or lower than those in groupⅠ(P<0.05),and had no significant difference with those in groups Ⅲ and Ⅳ(P>0.05);dry matter intake in group Ⅱ was significantly higher than that in the other groups(P<0.05). 2) Fecal energy and urine energy in groupsⅠandⅡwere significantly lower than those in groups Ⅲ andⅣ(P<0.05), and gross energy digestibility was significantly higher than that in groups ⅢandⅣ(P<0.05). 3)Ni-trogen retention rate, nitrogen intake, digestible nitrogen and retention nitrogen in group Ⅲ were the highest, and were significantly higher than those in groupsⅠand Ⅳ(P<0.05),but had no significant differences com-pared with group Ⅱ(P>0.05). 4)With the increase of supplemental levels of trace elements,apparent meta-bolic rate of trace elements were firstly increased and then decreased, and apparent metabolic rates of iron, copper, zinc, manganese and cobalt in group Ⅱ were the highest. 5)Group Ⅱ had the highest manganese deposition rate in longissimus dorsi and heart, and the highest iron, iodine, copper and manganese deposition in liver;in spleen,iron deposition in groupⅡ was the highest,iodine deposition in group Ⅳ was the highest;in kidney, zinc deposition in group Ⅱwas the highest,and iodine deposition in group Ⅰwas the highest. Un-der the conditions in the present study, the optimal combination of trace element requirements for Shaanbei white cashmere goats were as follows: iron 290.14 mg/kg, copper 18.19 mg/kg, zinc 81.62 mg/k, manga-nese 94.10 mg/kg and cobalt 0.31 mg/kg.
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