本研究观察了24头初次产仔的母猪（长白×大白）及其后代，根据产仔数量分为两组：正常组（n=8，平均产仔数量为11.5±1.2），产仔数量在7至14之间；大量组（n=16，平均产仔数量为15.9±1.0），产仔数量在15至20之间。母猪在妊娠期间群养，在产褥期及哺乳期采用可调宽松住房系统（2.4×2.3米）进行饲养。所有母猪在分娩发动后的7天内被限制在分娩笼（0.6×2.3米）中。采集母猪的唾液样本分别在离分娩前的35、21和7天（D-35、D-21和D7，分别表示）以及分娩后的1、7和28天（D1、D7和D28，分别表示）进行收集，测量Trolox当量抗氧化能力（TEAC）、过氧化氢（H2O2）、高级氧化蛋白产物（AOPP）和肿瘤坏死因子-α（TNF-α）的水平。采集初乳样本进行催产素和泌乳素测定。通过视频分析观察分娩前24小时和分娩过程中的筑巢行为。结果显示，大量组母猪在分娩后的第1天和第7天H2O2水平以及晚孕期间AOPP水平较正常组母猪更高（p<0.05，对于所有指标），而晚孕期和分娩后第7天和第28天的TEAC水平较低（p<0.05，对于所有指标）。此外，大量组母猪在分娩后的第1天和第7天有较高的TNF-α水平趋势（p<0.10，对于两个指标）。大量组母猪在分娩前24-12小时的筑巢行为持续时间较短、频率较低（p<0.05，对于两个指标），并且泌乳素水平较低（p=0.10）。此外，大量组母猪分娩持续时间较长、死产率较高的趋势（p=0.06，p=0.07，分别表示）。总之，本研究证实大产仔数量可能会增加母猪在晚孕期和哺乳期间的氧化应激。数据还表明，这可能对泌乳素释放产生不利影响，从而导致筑巢行为减少。版权所有 © 2023 Lee, Shin, Jo, Lee and Yun.

The study examined 24 primiparous sows (Landrace × Large white) and their offspring, which were grouped based on litter size: NORMAL (n = 8, average litter size 11.5 ± 1.2), with litter size between 7 and 14, and LARGE (n = 16, average litter size 15.9 ± 1.0), with litter size between 15 and 20. Sows were group-housed during gestation, and housed in an adjustable loose housing system (2.4 × 2.3 m) during farrowing and lactation. All the sows were confined in the farrowing crates (0.6 × 2.3 m) for 7 days after the onset of parturition. Saliva samples of sows were collected on days 35, 21, and 7 before farrowing (D-35, D-21 and D7, respectively), and on days 1, 7, and 28 after farrowing (D1, D7, and D28, respectively) to measure the levels of Trolox equivalent antioxidant capacity (TEAC), hydrogen peroxide (H2O2), advanced oxidation protein products (AOPP), and tumor necrosis factor-alpha (TNF-α). Colostrum samples were collected for oxytocin and prolactin assays. Nest-building behavior (NB) for 24 h before parturition and farrowing was observed through video analysis. The results showed that LARGE sows had higher levels of H2O2 on D1 and D7 and AOPP during late gestation (p < 0.05, for all) and lower TEAC levels during late gestation and on D7 and D28 after farrowing (p < 0.05, for all) than NORMAL sows. Additionally, LARGE sows tended to have higher levels of TNF-α on D1 and D7 (p < 0.10, for both). LARGE sows showed shorter duration and lower frequency of NB during 24-12 h before parturition (p < 0.05, for both), and tended to have lower prolactin levels (p = 0.10). Furthermore, large sows tended to show longer farrowing duration and higher stillbirth rate (p = 0.06, p = 0.07, respectively). In conclusion, this study confirmed that large litter size may increase oxidative stress in sows during late gestation and lactation. The data also suggested that this could adversely impact prolactin release, leading to reduced NB.Copyright © 2023 Lee, Shin, Jo, Lee and Yun.