Endemic and epidemic outbreaks of porcine reproductive and respiratory syndrome virus (PRRSV) are causing large economic losses in commercial pig production worldwide. Given the complexity of controlling this disease with vaccines or other biosecurity measures, the selection for pigs with a natural resilience to this infection has been proposed as an alternative approach. In this context, we previously reported a vaccine-based protocol to classify 6-week-old female piglets from one farm into resilient and susceptible phenotypes. Subsequent analysis showed that resilient sows had fewer lost piglets during a PRRSV epidemic. In the present study, we validated the results in four additional farms by showing a robust effect on the percentage of piglets lost (P<0.05). We were able to associate the resilient phenotype with a 2-4% reduction in piglet losses on sow farms in both endemic and endemic/epidemic situations. Also consistent with previous results, susceptible sows delivered on average, almost 0.5 more piglets born per parity (P<0.05). However, we show here that resilient sows have a longer stayability in the farm (+57 d; P<0.05) and +0.3 more successful parities (P<0.05), which balances the total number of piglets born and born alive in the full productive life of the sow between the two groups. Resilient sows thus contribute towards to a more sustainable production system, reducing sow replacement and piglet mortality. The validation of this protocol on four independent production farms paves the way for the study of the genetic variation underlying the resilient/susceptible classification, with a view to incorporating this information into selection programs in the future.

中文翻译：

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验证一种表型分析方法，以识别 PRRSV 适应力母猪及其对母猪存活率的影响


猪繁殖与呼吸综合征病毒 （PRRSV） 的地方性和流行性疫情正在给全球商品生猪生产造成巨大经济损失。鉴于使用疫苗或其他生物安全措施控制这种疾病的复杂性，已提议选择对这种感染具有天然适应力的猪作为替代方法。在此背景下，我们之前报道了一种基于疫苗的方案，将一个猪场的 6 周龄母猪分为有弹性和易感的表型。随后的分析表明，在 PRRSV 流行期间，有弹性的母猪损失的仔猪较少。在本研究中，我们通过显示对仔猪损失百分比的稳健影响 （P<0.05） 验证了另外四个猪场的结果。我们能够将弹性表型与地方性和地方性/流行情况下母猪场仔猪损失减少 2-4% 联系起来。同样与之前的结果一致，易感母猪平均每胎多产仔数近 0.5 头 （P<0.05）。然而，我们在这里表明，有弹性的母猪在猪场的存活时间更长（+57 d;P<0.05）和 +0.3 个成功胎次 （P<0.05），它平衡了两组母猪完整生产寿命中出生和活产的仔猪总数。因此，有弹性的母猪有助于建立更可持续的生产系统，减少母猪更换和仔猪死亡率。该方案在四个独立生产农场的验证为研究弹性/易感分类背后的遗传变异铺平了道路，以期将这些信息纳入未来的选择计划。