Effects of dietary oyster peptide supplement on litter performance, immunological response of sows and growth performance of piglets

Animal breeding and reproduction techniques has led to an increase in the number of offspring of sows. However, weak piglets and low survival rate of piglets occurs frequently. During pregnancy, the late gestation is the most crucial period for fetal weight gain. Oyster peptides (OPI) are regarded as functional active substances derived from oysters with significant nutritional and medicinal value, exhibiting considerable potential for application. It remains unclear whether oyster peptides can play an important role in the field of sow reproduction. In this study, the objective was to investigate the impact of incorporating OPI into the diets of sows during the late gestation and lactation phases on litter performance, immunological response of sows and the growth and development of piglets. 100 sows were selected and were randomly divided into the control group (CON, basic diet) and the experimental group (OPI, supplemented with 2 mg/kg OPI in feed) with the feeding period from gestation day 90 to day 21 postpartum. First, litter performance, immunological response of sows and growth performance of piglets were analyzed; then, RNA-seq and q-PCR were used to detect the molecular mechanism of OPI. The results demonstrated that the supplementation of OPI to the diets of sows in late gestation and lactation resulted in a significant increase in the number of healthy piglets and weaning survival rate ; colostrum and placenta samples were collected during parturition, IgA, IgG and IgM in colostrum of sows also increased; expression levels of glucose transporter genes (GLUT4, SLC2A1), amino acid transporter genes (SNAT1, LAT1), and fatty acid transporter genes (FABP3) in the placenta were increased. The levels of pro-inflammatory factors (IL-1, IL-6, IL-8, AVPI1) were significantly decreased in the placenta, whereas the levels of anti-inflammatory factors (IL-10), antioxidant genes (SOD1, SOD2, GPX2, CAT), and anti-apoptotic genes (BCL2, BCL2L1) were significantly elevated. It can be concluded that oyster peptides can be used in pig production to increase the number of healthy piglets, this may be caused by enhancing the immune level of sows and improving expression level of transporter, antioxidant and immune genes of the placenta.

畜禽育种与繁殖技术的进步提升了母猪的产仔数，但随之而来的是弱仔频发、仔猪成活率偏低的问题。母猪妊娠期间，妊娠晚期是胎儿体重增长的关键阶段。牡蛎肽（Oyster Peptides, OPI）是从牡蛎中提取的功能性活性物质，兼具优异的营养与药用价值，具备广阔的应用潜力。目前尚不清楚牡蛎肽能否在母猪繁殖领域发挥关键作用。本研究旨在探究在妊娠晚期及泌乳期母猪日粮中添加OPI对母猪产仔性能、免疫功能以及仔猪生长发育的影响。本试验选取100头母猪，随机分为对照组（CON，基础日粮）与试验组（OPI，日粮中添加2 mg/kg OPI），试验周期为妊娠第90天至产后第21天。首先分析母猪产仔性能、免疫功能与仔猪生长性能；随后采用RNA-seq与q-PCR技术检测OPI发挥作用的分子机制。试验结果显示，在妊娠晚期及泌乳期母猪日粮中添加OPI，可显著提升健康仔猪数与断奶成活率；分娩时采集初乳与胎盘样本，母猪初乳中的IgA、IgG与IgM水平亦显著升高；胎盘中的葡萄糖转运蛋白基因（GLUT4、SLC2A1）、氨基酸转运蛋白基因（SNAT1、LAT1）以及脂肪酸转运蛋白基因（FABP3）的表达水平显著上调。胎盘中促炎因子（IL-1、IL-6、IL-8、AVPI1）的表达水平显著降低，而抗炎因子（IL-10）、抗氧化基因（SOD1、SOD2、GPX2、CAT）以及抗凋亡基因（BCL2、BCL2L1）的表达水平显著升高。综上，牡蛎肽可应用于生猪生产以提升健康仔猪数，其作用机制可能与增强母猪免疫功能、上调胎盘转运蛋白、抗氧化及免疫相关基因的表达水平有关。