Hopkins Danielle, Poljak Zvonimir, Farzan Abdolvahab, Friendship Robert
Department of Population Medicine, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1.
Can Vet J. 2018 Jun;59(6):623-630.
The objective of this study was to investigate the association between sow- and litter-level factors with mortality in a swine nursery barn experiencing a severe disease outbreak. All-cause mortality data from a 300-sow farrow-to-finish herd was analyzed using a Cox's regression model. The data were recorded over 6 months and included 24 cohorts, 297 sows, 295 litters, and 2779 piglets with an average of 14.4% post-weaning mortality. If the sows had 2 litters within the study period and pigs from their first litter experienced mortality, then pigs from their subsequent litter had a decreased risk of mortality [hazard ratio (HR) = 0.34, < 0.05]. Pigs were more likely to experience mortality if at least 1 additional littermate experienced mortality (HR = 9.22, = 0.001). Under conditions of this study, the results suggest mechanisms related to sow immunity and within-litter spread that could have contributed to the risk of mortality during the outbreak.
本研究的目的是调查在经历严重疾病爆发的仔猪保育舍中，母猪和窝内因素与死亡率之间的关联。使用Cox回归模型分析了一个拥有300头母猪的全进全出猪群的全因死亡率数据。数据记录了6个月，包括24个群组、297头母猪、295窝仔猪和2779头仔猪，断奶后平均死亡率为14.4%。如果母猪在研究期间产了2窝仔猪，且其第一窝仔猪出现了死亡情况，那么其后续窝的仔猪死亡风险降低[风险比(HR)=0.34，<0.05]。如果至少有1头同窝仔猪死亡，仔猪更有可能死亡(HR = 9.22，= 0.001)。在本研究条件下，结果表明与母猪免疫力和窝内传播相关的机制可能导致了疾病爆发期间的死亡风险。
