Functional corpora lutea (CL) are required for pregnancy establishment and gestational maintenance in swine, and CL function is susceptible to environmental influences. Manganese (Mn) could be critical in regulating CL function since it is a component of the antioxidant enzyme Mn superoxide dismutase (MnSOD) as well as enzymes involved in cholesterol and steroid hormone synthesis. We hypothesized that a more bioavailable dietary Mn source would increase Mn content in the CL thereby influencing luteal function during the mid-luteal phase of the estrous cycle. Postpubertal gilts (n = 32) were assigned to one of four gestation diets. The control diet (CON) met or exceeded National Research Council (2012) requirements and was formulated to contain 20 parts per million (ppm) of added Mn in the form of Mn sulfate. Three additional diets included 20 (treatment [TRT]1), 40 (TRT2), or 60 (TRT3) ppm of added Mn from a Mn–amino acid complex (Availa-Mn; Zinpro Corporation) instead of Mn sulfate. Dietary treatment began at estrus synchronization onset and continued through 12 days post estrus (dpe) of the ensuing estrous cycle. Blood samples were collected at estrus onset, which was assigned as 0 dpe, as well as 4, 8, and 12 dpe. Gilts were euthanized and tissues were collected at 12 dpe. Serum progesterone (P4) increased (P < 0.01) from 0 to 12 dpe but was unaffected by dietary treatment (P = 0.15) and there was no effect of the interaction between day and treatment (P = 0.85). Luteal Mn content increased (P ≤ 0.05) by 19%, 21%, and 24% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Luteal P4 concentrations decreased (P = 0.03) 25%, 26%, and 32% in gilts fed TRT1, TRT2, and TRT3, respectively, compared to CON. Relative to CON gilts, CL calcium content decreased (P = 0.02) by 36%, 24%, and 34% for TRT1, TRT2, and TRT3 gilts, respectively. Collectively, these data support the hypothesis that feeding a more bioavailable Mn source increases Mn accumulation in CL tissue. If and how this influences CL function may be related to altered luteal P4 concentrations.

中文翻译：

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锰氨基酸复合物对后备母猪组织特异性微量矿物质分布和黄体功能的影响

猪的妊娠建立和妊娠维持需要功能性黄体（CL），并且CL功能易受环境影响。锰 (Mn) 对调节 CL 功能至关重要，因为它是抗氧化酶锰超氧化物歧化酶 (MnSOD) 以及参与胆固醇和类固醇激素合成的酶的组成部分。我们假设生物利用度更高的膳食锰源会增加 CL 中的锰含量，从而影响发情周期黄体中期的黄体功能。将青春期后的后备母猪 (n = 32) 分配到四种妊娠日粮中的一种。对照日粮 (CON) 达到或超过了国家研究委员会 (2012) 的要求，配方中添加了 20 ppm (ppm) 的硫酸锰形式的锰。三种额外的日粮包括 20（处理 [TRT]1）、40（TRT2）或 60（TRT3）ppm 来自 Mn-氨基酸复合物（Availa-Mn；Zinpro Corporation）添加的 Mn，而不是硫酸锰。饮食治疗在发情同步开始时开始并持续到随后的发情周期的发情后(dpe) 12天。在发情开始时收集血样，分配为 0 dpe，以及 4、8 和 12 dpe。后备母猪被安乐死并在 12 dpe 时收集组织。血清黄体酮 (P4) 从 0 到 12 dpe 增加（P < 0.01），但不受饮食治疗的影响（P = 0.15），并且日和治疗之间的相互作用没有影响（P = 0.85）。与 CON 相比，饲喂 TRT1、TRT2 和 TRT3 的后备母猪的黄体 Mn 含量分别增加了 19%、21% 和 24%（P ≤ 0.05）。黄体 P4 浓度下降 (P = 0.03) 25%, 26%, 与 CON 相比，饲喂 TRT1、TRT2 和 TRT3 的后备母猪分别增加了 32%。相对于 CON 后备母猪，TRT1、TRT2 和 TRT3 后备母猪的 CL 钙含量分别降低了 (P = 0.02) 36%、24% 和 34%。总的来说，这些数据支持这样的假设，即喂养更具生物可利用性的锰源会增加 CL 组织中的锰积累。这是否以及如何影响 CL 功能可能与改变的黄体 P4 浓度有关。