Olson P A, Brink D R, Hickok D T, Carlson M P, Schneider N R, Deutscher G H, Adams D C, Colburn D J, Johnson A B
Department of Animal Science, University of Nebraska, Lincoln 68583-0908, USA.
J Anim Sci. 1999 Mar;77(3):522-32. doi: 10.2527/1999.773522x.
The objective of this study was to determine whether a combination of Cu, Co, Mn, and Zn in an organic or inorganic form fed at higher than nutrient recommendations for 2-yr-old cows from calving to breeding would affect pregnancy rate, calving date, calf performance, and cow liver and serum mineral concentrations. Crossbred 2-yr-old cows were used after calving in 1994 (n = 127) and 1995 (n = 109). Cows were blocked by calving date to one of three treatments: 1) no supplemental minerals (CTL), 2) organic minerals (ORG), or 3) inorganic minerals (ING). Minerals were fed for the same daily intake for both organic and inorganic treatments: Cu (125 mg), Co (25 mg), Mn (200 mg), and Zn (360 mg). Cows were individually fed a mineral-protein supplement with grass hay from calving (February-March) to before breeding (May 15). Hay intakes were calculated using chromium oxide boluses to determine fecal output. Fecal excretion of minerals was calculated following trace element analysis of feces. Liver biopsies were obtained before calving, after calving (start of supplementation), at the end of supplementation, and in midsummer. Over 2 yr, more cows did not become pregnant (P < .01) in ORG (11/78) and ING (11/78) treatments than in CTL (0/80) treatments. A treatment x year interaction was found for day of conception. Cows in the ORG group conceived later (P < .01) than cows in the ING or CTL groups in 1994. In 1995, there was no difference (P > .10) in day of conception among groups. Liver Zn and Mn concentrations were not different (P > .10) and Cu concentrations increased (P < .01) for the ORG and ING groups. Cows in the ORG and ING groups had higher (P < .01) concentrations of Cu, Mn, and Zn in the feces than the CTL cows. Trace elements in the feces did not differ for ORG and ING groups. Results indicate that combinations of Cu, Co, Mn, and Zn fed at higher levels than are required reduced reproductive performance.
本研究的目的是确定在1994年（n = 127头）和1995年（n = 109头）产犊至配种期间，以高于营养推荐量的有机或无机形式饲喂2岁母牛的铜、钴、锰和锌组合是否会影响妊娠率、产犊日期、犊牛性能以及母牛肝脏和血清矿物质浓度。1994年和1995年产犊后的杂种2岁母牛被用于试验。母牛按产犊日期分为三种处理之一：1）不补充矿物质（对照，CTL），2）有机矿物质（ORG），或3）无机矿物质（ING）。有机和无机处理中矿物质的每日摄入量相同：铜（125毫克）、钴（25毫克）、锰（200毫克）和锌（360毫克）。从产犊（2月至3月）到配种前（5月15日），给母牛单独饲喂矿物质 - 蛋白质补充剂和禾本科干草。使用氧化铬丸剂计算干草摄入量以确定粪便排出量。通过对粪便进行微量元素分析计算矿物质的粪便排泄量。在产犊前、产犊后（开始补充时）、补充结束时和仲夏采集肝脏活检样本。在两年期间，ORG组（11/78）和ING组（11/78）中未怀孕的母牛比CTL组（0/80）更多（P < 0.）。发现受孕日期存在处理×年份交互作用。1994年，ORG组的母牛受孕时间比ING组或CTL组的母牛晚（P < 0.）。1995年，各组之间受孕日期没有差异（P > 0.10）。ORG组和ING组的肝脏锌和锰浓度没有差异（P > 0.10），铜浓度升高（P < 0.）。ORG组和ING组母牛粪便中的铜、锰和锌浓度高于CTL组母牛（P < 0.）。ORG组和ING组粪便中的微量元素没有差异。结果表明，以高于所需水平饲喂铜、钴、锰和锌的组合会降低繁殖性能。
