Piglet pre-weaning mortality (PWM) is a significant issue in the U.S. swine industry, causing economic losses and raising sustainability and animal welfare concerns. This study conducted a multivariable analysis to identify factors associated with PWM in a Midwestern U.S. swine production system. Weekly data from 47 sow farms (7207 weaning weeks) were captured from January 2020 to December 2022. Initially, 29 variables regarding farm infrastructure, productivity parameters, health status, and interventions were selected for univariate analysis to assess their association with PWM. The initial multivariable analysis included the variables with P < 0.20 in the univariate analyses. A backward stepwise model selection was conducted by excluding variables with P > 0.05, and the final multivariable model consisted of 19 significant risk factors and 6 interaction terms. The overall average PWM for the study population was 14.02 %. Yearly variations in PWM were observed, with the highest recorded in 2020 (16.61 %) and the lowest in 2021 (15.78 %). Cohorts with a pond water source, lower farrowing rate (71.9 %), higher farrowing parity (5.1), shorter gestation length (116.2 days), and using oxytocin during farrowing had increased PWM. The higher productivity parameters such as mummies rate, stillborn rate, and average total born, the higher the PWM was. Additionally, health status and intervention-related factors were associated with PWM, where higher PWM rates were observed in herds facing porcine reproductive and respiratory syndrome virus (PRRSV) outbreaks, porcine epidemic diarrhea virus (PEDV) positive, the weeks before and during feed medication, and weeks without using Rotavirus vaccine or Rotavirus feedback. Altogether, these results corroborate that PWM is a multifactorial problem, and a better understanding of the risk factors is essential in developing strategies to improve survival rates. Therefore, this study identified the major risk factors associated with PWM for groups of pigs raised under field conditions, and the results underscore the significance of data analysis in comprehending the unique challenges and opportunities inherent to each system.

中文翻译：

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2020年至2022年美国中西部养猪生产系统仔猪断奶前死亡率相关的风险因素


仔猪断奶前死亡率 (PWM) 是美国养猪业的一个重大问题，造成经济损失并引发可持续性和动物福利问题。本研究进行了多变量分析，以确定与美国中西部养猪系统中 PWM 相关的因素。从 2020 年 1 月到 2022 年 12 月，我们捕获了 47 个母猪场（7207 断奶周）的每周数据。最初，选择了有关农场基础设施、生产力参数、健康状况和干预措施的 29 个变量进行单变量分析，以评估它们与 PWM 的关联。初始多变量分析包括单变量分析中 P < 0.20 的变量。通过排除 P> 0.05 的变量进行向后逐步模型选择，最终的多变量模型由 19 个显着风险因素和 6 个交互作用项组成。研究人群的总体平均 PWM 为 14.02%。观察到 PWM 的年度变化，最高记录出现在 2020 年（16.61%），最低记录出现在 2021 年（15.78%）。具有池塘水源、较低的产仔率（71.9%）、较高的产仔胎次（5.1）、较短的妊娠长度（116.2 天）以及在产仔期间使用催产素的队列增加了 PWM。木乃伊率、死产率、平均总出生率等生产率参数越高，PWM 越高。此外，健康状况和干预相关因素与 PWM 相关，在面临猪繁殖与呼吸综合征病毒 (PRRSV) 爆发、猪流行性腹泻病毒 (PEDV) 阳性、饲料用药前几周和期间的猪群中观察到较高的 PWM 率，以及几周没有使用轮状病毒疫苗或轮状病毒反馈。 总而言之，这些结果证实 PWM 是一个多因素问题，更好地了解风险因素对于制定提高生存率的策略至关重要。因此，本研究确定了在田间条件下饲养的猪群与 PWM 相关的主要风险因素，结果强调了数据分析在理解每个系统固有的独特挑战和机遇方面的重要性。