INRA, UMR1300 Bio-Agression Epidémiologie et Analyse de Risque en santé animale, F-44300 Nantes, France.
J Anim Sci. 2011 Jul;89(7):2210-9. doi: 10.2527/jas.2010-2916. Epub 2011 Feb 4.
In Europe, on-farm biosecurity measures, involving a strict all-in/all-out batch-management system and decontamination of the rearing rooms between consecutive batches, are recommended to control Salmonella infection in growing pigs. However, implementation of these measures is often relaxed under common farming conditions. Therefore, this study was conducted to assess the relative contributions of batch-management system and room decontamination efficacy on Salmonella seroprevalence for different growing rates and subsequent slaughter ages of pigs. Because the impact of these factors cannot be easily evaluated by an observational approach in commercial farms, a stochastic simulation model representing the population dynamics, herd management, and Salmonella infection within a farrow-to-finish pig herd was used. Realistic levels were set for each factor under study (3 for batch-management system and slaughter age; 4 for room decontamination) to generate 54 simulation scenarios. Salmonella shedding prevalence in groups of slaughter pigs was then compared. A sensitivity analysis was performed to rank the impacts of the 3 factors on output. Batch-management system had little effect. In contrast, room decontamination efficacy had the greatest impact on Salmonella prevalence in pigs at slaughter. A drop in decontamination efficacy from 100 to 50%, with a strict all-in/all-out batch-management system and for all slaughter ages tested, noticeably increased (P<0.001) the prevalence and almost doubled it for the reference slaughter age. Our results suggest that the control of Salmonella in pig herds should primarily focus on room decontamination efficacy. Provided that a good level of room decontamination is ensured, some flexibility in batch management, in terms of pig mixing, would be acceptable to limit the number of underweight pigs delivered to the slaughterhouse.
在欧洲，推荐在农场实施生物安全措施，包括严格的全进全出批次管理系统和连续批次间养殖室的消毒，以控制生长猪中的沙门氏菌感染。然而，在常见的养殖条件下，这些措施的实施往往会放宽。因此，本研究旨在评估批次管理系统和房间消毒效果对不同生长速度和随后屠宰年龄的猪的沙门氏菌血清阳性率的相对贡献。由于这些因素的影响在商业农场中很难通过观察方法进行评估，因此使用了一个代表种群动态、 herd 管理和生长猪群内沙门氏菌感染的随机模拟模型。为每个研究因素（批次管理系统和屠宰年龄为 3；房间消毒为 4）设定了现实水平，以产生 54 个模拟场景。然后比较了屠宰猪群中沙门氏菌脱落的流行率。进行了敏感性分析，以对 3 个因素对输出的影响进行排名。批次管理系统的影响很小。相比之下，房间消毒效果对屠宰时猪的沙门氏菌流行率影响最大。严格的全进全出批次管理系统和所有测试的屠宰年龄下，消毒效果从 100%降至 50%，明显增加（P<0.001）了流行率，并使参考屠宰年龄的流行率几乎翻了一番。我们的研究结果表明，猪群中沙门氏菌的控制应主要侧重于房间消毒效果。只要确保良好的房间消毒水平，在混合猪只方面，批次管理的灵活性在限制交付到屠宰场的体重不足的猪的数量方面是可以接受的。
