Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States; Setor de Suínos, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States.
Prev Vet Med. 2024 Nov;232:106316. doi: 10.1016/j.prevetmed.2024.106316. Epub 2024 Aug 16.
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.
仔猪断奶前死亡率（PWM）是美国养猪业的一个重大问题，导致经济损失，并引发可持续性和动物福利方面的担忧。本研究对美国中西部养猪生产系统中的 PWM 相关因素进行了多变量分析。该研究从 2020 年 1 月至 2022 年 12 月期间，每周从 47 个母猪场（7207 个断奶周）收集数据。最初，选择了 29 个与农场基础设施、生产参数、健康状况和干预措施有关的变量进行单变量分析，以评估它们与 PWM 的关系。初步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，最终的多变量模型包括 19 个显著的风险因素和 6 个交互项。研究人群的总体平均 PWM 为 14.02%。观察到 PWM 的年度变化，2020 年记录的 PWM 最高（16.61%），2021 年最低（15.78%）。池塘水源、较低的产仔率（71.9%）、较高的产仔胎次（5.1）、较短的妊娠期（116.2 天）和产仔时使用催产素的猪群，PWM 增加。产仔率、死胎率和平均总产仔数等较高的生产参数，PWM 越高。此外，健康状况和干预相关因素与 PWM 有关，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、投药前和投药期间以及未使用轮状病毒疫苗或轮状病毒反馈的猪群中，PWM 率较高。总的来说，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存活率的策略至关重要。因此，本研究确定了与在田间条件下饲养的猪群相关的 PWM 的主要风险因素，结果强调了数据分析在理解每个系统所面临的独特挑战和机遇方面的重要性。
