Lipori Chiara, Reimert Inonge, Knol Egbert F, Graat Elisabeth A M, van As Inge M, Kemp Bas, Soede Nicoline M
Adaptation Physiology Group, Wageningen University & Research, Wageningen, The Netherlands.
Research Center, Topigs Norsvin, Den Bosch, The Netherlands.
J Anim Sci. 2025 Jan 4;103. doi: 10.1093/jas/skaf134.
Selecting sows with a high genetic merit for mothering ability to ensure the survival of liveborn piglets may be a promising strategy to reduce piglet mortality in free farrowing (FF) systems. This genetic merit, reflected in the Estimated Breeding Value for Mothering Ability (EBVma), is currently estimated based on information from sows housed in conventional crated farrowing systems. Therefore, the objective of the present study was to assess the predictive ability of crated sow breeding values for mothering ability on early piglet mortality, litter characteristics, and farrowing performance in an FF environment. This was achieved by comparing the performance of sows during early lactation in FF with those that were temporarily crated (TC) for the first five days of lactation. A total of 56 healthy TN70 sows were assigned to either TC (crated from approximately 2 d pre-farrowing to day 5 of lactation, n = 28) or FF (n = 28). Overall, higher EBVma were associated with reduced liveborn piglet mortality within the first 5 d of lactation (P = 0.04). In FF, liveborn piglet mortality was higher in low EBVma sows (14.8%) compared to high EBVma sows (6.1%) (odds ratios [OR]: 3.4, 95% CI: 1.5-7.4, P = 0.003). Additionally, piglet crushing rates were higher in low EBVma sows (9.8%) versus high EBVma sows (3.3%) (OR: 2.9, 95% CI: 1.3-7.6, P = 0.01). In TC, the association was less pronounced for liveborn piglet mortality (OR: 2.4, 95% CI: 0.8-7.0, P = 0.11) but present for piglet crushing (OR: 8.4, 95% CI: 1.5-∞, P = 0.02). Higher EBVma values were also associated with a reduced probability of stillbirths (P = 0.02). However, no significant association was found between EBVma and farrowing duration in either housing system, nor was there an effect of housing system on farrowing duration (FF: 251 ± 48.5 min, TC: 251 ± 51.3 min, P = 0.96). As anticipated, piglet mortality was higher in FF (14.2%) compared to TC (5.9%), with piglet crushing being the predominant cause of piglet mortality in FF (11.8%), while deaths of nonviable piglets were more common in TC (4.2%). This study demonstrates that EBVma retain their predictive value in FF and suggests a stronger association with piglet survival in this environment. The significant association between higher EBVma and lower piglet mortality, particularly due to reduced piglet crushing, highlights the potential of genetic selection to enhance piglet survival in FF systems through selection for maternal influence on survival.
选择具有高遗传母性能力的母猪以确保出生仔猪的存活，可能是降低自由分娩（FF）系统中仔猪死亡率的一种有前景的策略。这种遗传价值通过母性能力估计育种值（EBVma）来体现，目前是根据传统产仔箱分娩系统中母猪的信息进行估计的。因此，本研究的目的是评估产仔箱母猪育种值对母性能力在FF环境下对早期仔猪死亡率、窝产特征和分娩性能的预测能力。这是通过比较FF环境下早期泌乳期母猪与泌乳前五天临时关在产仔箱（TC）中的母猪的性能来实现的。总共56头健康的TN70母猪被分配到TC组（从产前约2天至泌乳第5天关在产仔箱中，n = 28）或FF组（n = 28）。总体而言，较高的EBVma与泌乳前5天内出生仔猪死亡率降低相关（P = 0.04）。在FF组中，低EBVma母猪的出生仔猪死亡率（14.8%）高于高EBVma母猪（6.1%）（优势比[OR]：3.4，95%置信区间：1.5 - 7.4，P = 0.003）。此外，低EBVma母猪的仔猪被压死率（9.8%）高于高EBVma母猪（3.3%）（OR：2.9，95%置信区间：1.3 - 7.6，P = 0.01）。在TC组中，出生仔猪死亡率的关联不太明显（OR：2.4，95%置信区间：0.8 - 7.0，P = 0.11），但仔猪被压死情况存在关联（OR：8.4，95%置信区间：1.5 - ∞，P = 0.02）。较高的EBVma值也与死胎概率降低相关（P = 0.02）。然而，在两种饲养系统中，均未发现EBVma与分娩持续时间之间存在显著关联，饲养系统对分娩持续时间也没有影响（FF组：251 ± 48.5分钟，TC组：251 ± 51.3分钟，P = 0.96）。正如预期的那样，FF组的仔猪死亡率（14.2%）高于TC组（5.9%），仔猪被压死是FF组仔猪死亡的主要原因（11.8%），而在TC组中，无活力仔猪死亡更为常见（4.2%）。本研究表明，EBVma在FF环境中仍保持其预测价值，并表明在这种环境下与仔猪存活的关联更强。较高的EBVma与较低的仔猪死亡率之间的显著关联，特别是由于仔猪被压死减少，突出了通过选择对仔猪存活有母性影响的因素，利用遗传选择提高FF系统中仔猪存活率的潜力。
