Department of Animal Science, Iowa State University, Ames, IA 50011, USA.
Zinpro Corporation, Eden Prairie, MN 55344, USA.
J Anim Sci. 2021 Aug 1;99(8). doi: 10.1093/jas/skab155.
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.
功能性黄体（CL）对于猪的妊娠建立和妊娠维持是必需的，CL 功能易受环境影响。锰（Mn）在调节 CL 功能方面可能很重要，因为它是抗氧化酶 Mn 超氧化物歧化酶（MnSOD）以及参与胆固醇和甾体激素合成的酶的组成部分。我们假设，更具生物利用度的膳食 Mn 来源将增加 CL 中的 Mn 含量，从而影响发情周期中期的黄体功能。青春期后的母猪（n = 32）被分配到四种妊娠日粮之一。对照日粮（CON）符合或超过国家研究委员会（2012 年）的要求，并被设计为含有 20ppm 的硫酸锰作为添加 Mn。另外三种日粮包括 20（TRT1）、40（TRT2）或 60（TRT3）ppm 的添加 Mn，来自 Mn-氨基酸络合物（Availa-Mn；Zinpro 公司）而不是硫酸锰。日粮处理从发情同步开始，持续到发情周期的 12 天后（dpe）。在发情开始时采集血液样本，将其指定为 0dpe，以及 4、8 和 12dpe。母猪被安乐死，组织在 12dpe 时收集。血清孕酮（P4）从 0 到 12dpe 增加（P < 0.01），但不受日粮处理的影响（P = 0.15），并且日龄和处理之间没有相互作用的影响（P = 0.85）。与 CON 相比，分别饲喂 TRT1、TRT2 和 TRT3 的母猪黄体 Mn 含量分别增加了 19%、21%和 24%（P ≤ 0.05）。与 CON 相比，分别饲喂 TRT1、TRT2 和 TRT3 的母猪黄体 P4 浓度分别下降了 25%、26%和 32%（P = 0.03）。与 CON 母猪相比，TRT1、TRT2 和 TRT3 母猪的 CL 钙含量分别下降了 36%、24%和 34%（P = 0.02）。总的来说，这些数据支持这样的假设，即饲喂更具生物利用度的 Mn 源会增加 CL 组织中的 Mn 积累。如果以及如何影响 CL 功能可能与改变黄体 P4 浓度有关。
