Abstract：
BACKGROUND: Antimicrobial use (AMU) has decreased significantly in Dutch pig farms since 2009. However, this decrease has stagnated recently, with relatively high AMU levels persisting mainly among weaners. The aim of this study was to identify farm-level characteristics associated with: i) total AMU and ii) use of specific antimicrobial classes.
METHODS: In 2020, cross-sectional data from 154 Dutch pig farms were collected, including information on AMU and farm characteristics. A mixed-effects conditional Random Forest analysis was applied to select the subset of features that was best associated with AMU.
RESULTS: The main risk factors for total AMU in weaners were vaccination for PRRS in sucklings, being a conventional farm (vs. not), high within-farm density, and early weaning. The main protective factors for total AMU in sows/sucklings were E. coli vaccination in sows and having boars for estrus detection from own production. Regarding antimicrobial class-specific outcomes, several risk factors overlapped for weaners and sows/sucklings, such as farmer\'s non-tertiary education, not having free-sow systems during lactation, and conventional farming. An additional risk factor for weaners was having fully slatted floors. For fatteners, the main risk factor for total AMU was PRRS vaccination in sucklings.
CONCLUSIONS: Several factors found here to be associated with AMU. Some were known but others were novel, such as farmer\'s tertiary education, low pig aggression and free-sow systems which were all associated with lower AMU. These factors provide targets for developing tailor-made interventions, as well as an evidence-based selection of features for further causal assessment and mediation analysis.
METHODS: In 2020, cross-sectional data from 154 Dutch pig farms were collected, including information on AMU and farm characteristics. A mixed-effects conditional Random Forest analysis was applied to select the subset of features that was best associated with AMU.
RESULTS: The main risk factors for total AMU in weaners were vaccination for PRRS in sucklings, being a conventional farm (vs. not), high within-farm density, and early weaning. The main protective factors for total AMU in sows/sucklings were E. coli vaccination in sows and having boars for estrus detection from own production. Regarding antimicrobial class-specific outcomes, several risk factors overlapped for weaners and sows/sucklings, such as farmer\'s non-tertiary education, not having free-sow systems during lactation, and conventional farming. An additional risk factor for weaners was having fully slatted floors. For fatteners, the main risk factor for total AMU was PRRS vaccination in sucklings.
CONCLUSIONS: Several factors found here to be associated with AMU. Some were known but others were novel, such as farmer\'s tertiary education, low pig aggression and free-sow systems which were all associated with lower AMU. These factors provide targets for developing tailor-made interventions, as well as an evidence-based selection of features for further causal assessment and mediation analysis.
摘要：
背景：自2009年以来，荷兰养猪场的抗菌药物使用（AMU）显着下降。然而,这种减少最近停滞不前，相对较高的AMU水平主要在断奶者中持续存在。这项研究的目的是确定与以下各项相关的农场水平特征：i）总AMU和ii）使用特定的抗菌类别。
方法：在2020年，收集了154个荷兰养猪场的横截面数据，包括AMU和农场特色的信息。应用混合效应条件随机森林分析来选择与AMU最相关的特征子集。
结果：断奶者总AMU的主要危险因素是在乳牛中接种PRRS，作为一个传统的农场(与不是),农场内部密度高，和早期断奶。母猪/哺乳中总AMU的主要保护因素是母猪的大肠杆菌疫苗接种和有公猪从自己的生产中检测发情。关于抗菌类特异性结果，断奶仔猪和母猪/乳母的几个风险因素重叠，例如农民的非高等教育，哺乳期间没有自由母猪系统，传统农业。断奶者的另一个风险因素是地板完全板条。对于育肥者来说，总AMU的主要危险因素是乳牛PRRS疫苗接种.
结论：这里发现几个因素与AMU相关。有些是已知的，但其他人是小说，如农民的高等教育，低猪攻击性和自由母猪系统都与低AMU相关。这些因素为制定量身定制的干预措施提供了目标，以及基于证据的特征选择，以进行进一步的因果评估和调解分析。
方法：在2020年，收集了154个荷兰养猪场的横截面数据，包括AMU和农场特色的信息。应用混合效应条件随机森林分析来选择与AMU最相关的特征子集。
结果：断奶者总AMU的主要危险因素是在乳牛中接种PRRS，作为一个传统的农场(与不是),农场内部密度高，和早期断奶。母猪/哺乳中总AMU的主要保护因素是母猪的大肠杆菌疫苗接种和有公猪从自己的生产中检测发情。关于抗菌类特异性结果，断奶仔猪和母猪/乳母的几个风险因素重叠，例如农民的非高等教育，哺乳期间没有自由母猪系统，传统农业。断奶者的另一个风险因素是地板完全板条。对于育肥者来说，总AMU的主要危险因素是乳牛PRRS疫苗接种.
结论：这里发现几个因素与AMU相关。有些是已知的，但其他人是小说，如农民的高等教育，低猪攻击性和自由母猪系统都与低AMU相关。这些因素为制定量身定制的干预措施提供了目标，以及基于证据的特征选择，以进行进一步的因果评估和调解分析。
