The objective was to evaluate the effects of replacing inorganic trace minerals (ITM) with reduced levels of organic trace minerals (OTM) in proteinate forms and selenium yeast in the mineral premix of prepartal and lactating dairy goats on lactation performance, milk fatty acid (FA) composition, nutrient digestibility and antioxidant status. Xinong Saanen dairy goats (n = 40) were blocked by parity and body weight, and randomly assigned to either ITM or OTM treatments from 4 wk prepartum through 8 mo of lactation. Both groups received the same basal diet except for the trace mineral supplement. The ITM supplement included Fe, Cu, Zn, and Mn as sulfates, and Se as selenite to meet the recommendations. The OTM supplement included Fe, Cu, Zn, and Mn as proteinates at 50% of ITM supplement levels, and Se as Se-yeast at 100% of ITM supplement level. Sampling and measurements were performed in the 1st, 2nd, 4th, and 8th mo of lactation. Data were summarized by month and treatment, and analyzed using the Mixed Model of SPSS with repeated measures. OTM group showed lower milk fat (P = 0.02) and higher milk Se (P = 0.03) with no compromised effects on milk yield and milk protein compared to ITM group. Furthermore, OTM decreased the content of C6:0, C8:0, C10:0 (P < 0.05) and increased the content of odd- and branched-chain FAs (OBCFA) in milk fat due to greater content of C15:0 (P = 0.01) and anteiso C15:0 (P = 0.07). OTM led to greater total-tract digestibility of DM (P = 0.03), CP (P = 0.07), EE (P = 0.03) and ADF (P = 0.05). OTM goats showed less fecal excretion of Fe (P = 0.01), Cu (P < 0.01), and Zn (P = 0.08) compared to ITM goats. There was a tendency for greater serum GSH-Px activity (P = 0.09) with OTM. Overall, the long-term subsitution of reduced levels of OTM for ITM can change milk fat and fatty acid composition while maintaining milk yield, digestibility and antioxidant status.

中文翻译：

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矿物质混合物中蛋白质形式的有机微量矿物质和硒-酵母含量降低对奶山羊泌乳性能、乳脂肪酸组成、营养物质消化率和抗氧化状态的影响


目的是评估在预产期和泌乳期奶山羊的矿物质预混料中用降低水平的蛋白质形式有机微量矿物质 (OTM) 和硒酵母替代无机微量矿物质 (ITM) 对泌乳性能、乳脂肪酸 (FA) 的影响。 ) 成分、营养物质消化率和抗氧化状态。西农萨能奶山羊 (n = 40) 根据胎次和体重进行分组，并从产前 4 周到哺乳期 8 个月随机分配至 ITM 或 OTM 治疗组。除微量矿物质补充剂外，两组均接受相同的基础饮食。 ITM 补充剂包括硫酸盐形式的铁、铜、锌和锰，以及亚硒酸盐形式的硒，以满足建议。 OTM 补充剂包括 ITM 补充剂水平 50% 的 Fe、Cu、Zn 和 Mn 作为蛋白质盐，以及 ITM 补充剂水平 100% 的 Se 酵母硒。在哺乳期的第 1、2、4 和 8 个月进行采样和测量。按月份和治疗汇总数据，并使用 SPSS 混合模型进行重复测量分析。与 ITM 组相比，OTM 组乳脂较低（P = 0.02），乳硒较高（P = 0.03），但对产奶量和乳蛋白没有影响。此外，OTM 降低了乳脂中 C6:0、C8:0、C10:0 的含量 (P < 0.05)，并由于 C15:0 含量增加而增加了乳脂中奇数链和支链 FA (OBCFA) 的含量(P = 0.01) 和反异 C15:0 (P = 0.07)。 OTM 导致 DM (P = 0.03)、CP (P = 0.07)、EE (P = 0.03) 和 ADF (P = 0.05) 的全消化道消化率更高。与 ITM 山羊相比，OTM 山羊粪便中铁 (P = 0.01)、铜 (P < 0.01) 和锌 (P = 0.08) 的排泄量较少。 OTM 存在血清 GSH-Px 活性更高的趋势 (P = 0.09)。 总体而言，长期用降低水平的 OTM 替代 ITM 可以改变乳脂和脂肪酸组成，同时保持产奶量、消化率和抗氧化状态。