Maternal proline (Pro) supplementation enhances fetal survival and placental development in mice. However, the effect of Pro on fetal and placental development in gilts remains to be investigated, particularly in the context of obesity-induced impaired pregnancy. Here, we investigated the effect of dietary Pro on fetal and placental development in obese gilts. Exp.1: On day 60 of gestation, forty-eight gilts with similar delivery times were selected and followed up until delivery to determine the relationship between maternal obesity, litter performance, and Pro abundance in term placentae. The results showed that impaired reproductive performance was associated with body condition parameters and inadequate placental Pro availability of gilts. Exp. 2: A total of 114 gilts were then used in a 2 × 3 factorial design to investigate the interaction between body condition (factor I: normal or obese gilts) and dietary Pro levels [factor II: low (0.89%, L-Pro), medium (1.39%, M-Pro), and high (1.89%, H-Pro)] on farrowing performance and placental angiogenesis. This resulted in six treatment combinations: normal-L-Pro, obese-L-Pro, normal-M-Pro, obese-M-Pro, normal-H-Pro, and obese-H-Pro. The effective number of replicates per group was 17, 21, 19, 21, 18, and 18, respectively (1 gilt per replicate). The results showed that increasing Pro intake increased piglet birth weight (P = 0.001), litter weight (P < 0.001), placental efficiency (P = 0.036) and placental vascular density (P < 0.001), and decreased the number of mummified fetuses (P = 0.001), the rate of low-birth-weight piglets (P = 0.005), and the rate of invalid piglets (P = 0.029). Interaction effects were observed between body condition and dietary Pro levels on piglet birth weight (P = 0.046), within-litter birth weight variation (P = 0.012), and placental vascular density (P = 0.007). Moreover, the beneficial effect of Pro on farrowing performance may be related to the improvement of sirtuin 1-superoxide dismutase 2-mitochondrial reactive oxygen species axis homeostasis and angiogenesis in the placenta. Our results suggest that gestation diets need to provide adequate Pro to meet the needs of fetal and placental development, particularly in obese gilts.

中文翻译：

---

妊娠期间增加脯氨酸摄入量可缓解后备母猪肥胖相关的胎儿发育和胎盘功能受损


母体脯氨酸 （Pro） 补充剂可提高小鼠的胎儿存活率和胎盘发育。然而，Pro 对后备母猪胎儿和胎盘发育的影响仍有待研究，特别是在肥胖诱导妊娠受损的情况下。在这里，我们研究了饮食 Pro 对肥胖后备母猪胎儿和胎盘发育的影响。实验 1： 在妊娠第 60 天，选择具有相似分娩时间的 48 头后备母猪并随访直至分娩，以确定母体肥胖、窝产性能和足月胎盘原丰度之间的关系。结果表明，繁殖性能受损与身体状况参数和后备母猪胎盘 Pro 可用性不足有关。实验 2：然后，在 2 × 3 析因设计中使用总共 114 头后备母猪，以研究身体状况（因子 I：正常或肥胖的后备母猪）与日粮 Pro 水平 [因子 II：低 （0.89%，L-Pro）、中 （1.39%，M-Pro） 和高 （1.89%，H-Pro）] 对分娩性能和胎盘血管生成的影响。这导致了六种治疗组合：normal-L-Pro、obese-L-Pro、normal-M-Pro、obese-M-Pro、normal-H-Pro 和 obese-H-Pro。每组有效重复数分别为 17 、 21 、 19 、 21 、 18 和 18 （每个重复 1 头后备母猪）。结果表明，增加 Pro 摄入量增加了仔猪出生体重 （P = 0.001）、窝重 （P < 0.001）、胎盘效率 （P = 0.036） 和胎盘血管密度 （P < 0.001），并降低了木乃伊胎儿的数量 （P = 0.001）、低出生体重仔猪率 （P = 0.005） 和无效仔猪率 （P = 0.029）。观察到身体状况和日粮 Pro 水平对仔猪出生体重的交互作用 （P = 0.046）、窝内出生体重变异 （P = 0.012） 和胎盘血管密度 （P = 0.007）。此外，Pro 对分娩性能的有益影响可能与胎盘中 sirtuin 1-超氧化物歧化酶 2-线粒体活性氧轴稳态和血管生成的改善有关。我们的结果表明，妊娠日粮需要提供足够的 Pro 来满足胎儿和胎盘发育的需要，尤其是在肥胖的后备母猪中。