1Faculty of Life Sciences, Department of Large Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, DK-1870 Frederiksberg C, Denmark.
Animal. 2010 Nov;4(11):1922-8. doi: 10.1017/S1751731110001102.
Sows suffering from clinical signs of disease (e.g. lameness, wounds and shoulder ulcers) are often involuntarily culled, affecting the farmer's economy and the welfare of the animals. In order to investigate the interrelationships between clinical signs of individual pregnant group-housed sows, we performed an explanatory factor analysis to identify factors describing the patterns of variation of clinical signs. Moreover, we investigated how these emerging factors affected the probability of a sow to be either (i) euthanized, (ii) suddenly dead, (iii) sent to slaughter due to clinical signs of disease such as claw lesions or wounds or (iv) involuntarily culled (representing a pool of sows that were either euthanized, dead or sent to slaughter due to disease). Data from 2.989 pregnant sows in group-housing systems from 33 sow herds were included in the study. A thorough clinical examination was performed for each sow by using a protocol including 16 different clinical signs. Farmers recorded all cullings and deaths and the reasons for these actions in a 3-month period after the clinical examination. Among the observed sows, 4.2% were involuntarily culled during the 3-month period. From the explanatory factor analysis, we identified three factors describing the underlying structure of the 16 clinical variables. We interpreted the factors as 'pressure marks', 'wounds' and 'lameness' Logistic analyses were performed to investigate the effect of the three factors and the parity number of each sow on the four outcomes: (i) euthanized, (ii) suddenly dead, (iii) sent to slaughter due to clinical signs of disease and (iv) involuntarily culled. The analyses showed that 'lameness' significantly increased the risk of sows to be involuntarily culled (P = 0.016) or sent to slaughter due to clinical signs of disease (P = 0.026). Lameness is generally considered to be an important welfare problem in sows, which could explain the increased risk seen in this study. By contrast, 'pressure marks' and 'wounds' did not have any significant effect on the four outcomes (P > 0.05).
患有临床疾病（例如跛行、伤口和肩部溃疡）的母猪通常会被非自愿淘汰，这会影响农民的经济和动物福利。为了研究个体妊娠群体饲养母猪的临床体征之间的相互关系，我们进行了一项解释性因素分析，以确定描述临床体征变化模式的因素。此外，我们还研究了这些新出现的因素如何影响母猪被（i）安乐死、（ii）突然死亡、（iii）因爪病或伤口等疾病临床症状而被送往屠宰场或（iv）非自愿淘汰的概率（代表因疾病而被安乐死、死亡或送往屠宰场的母猪池）。该研究纳入了来自 33 个母猪场的 2989 头妊娠母猪的数据。通过使用包括 16 种不同临床体征的方案，对每头母猪进行了彻底的临床检查。农民在临床检查后 3 个月内记录了所有淘汰和死亡以及这些行动的原因。在所观察的母猪中，有 4.2%在 3 个月内被非自愿淘汰。从解释性因素分析中，我们确定了描述 16 个临床变量潜在结构的三个因素。我们将这些因素解释为“压力痕迹”、“伤口”和“跛行”。进行了逻辑分析，以研究三个因素和每头母猪的产仔数对四个结果的影响：（i）安乐死，（ii）突然死亡，（iii）因临床症状而被送往屠宰场，以及（iv）非自愿淘汰。分析表明，“跛行”显著增加了母猪被非自愿淘汰（P=0.016）或因临床症状被送往屠宰场的风险（P=0.026）。跛行通常被认为是母猪的一个重要福利问题，这可以解释本研究中观察到的风险增加。相比之下，“压力痕迹”和“伤口”对四个结果没有任何显著影响（P>0.05）。
