統進統出(All-in and all-out, AIAO)蛋雞場易於經營管理，可減少雞隻與雞蛋的病原菌汙染機率，確保食品安全。然而臺灣一般蛋雞場仍不清楚統進統出之有效管理，常無法達到預期效益。本研究目的在比較統進統出與常見的多雞齡飼養模式下之微生物衛生指標上的差異，以釐清統進統出飼養模式下，其微生物衛生安全指標是否優於多雞齡飼養模式，且能提升產蛋率與降低雞隻死亡率。試驗以兩棟開放式傳統平面蛋雞舍為研究對象，分別為統進統出與多雞齡飼養模式之雞舍，進行兩次微生物衛生狀態之採樣分析。樣品採樣來源包括飼料槽、飲水器及產蛋籠底部；雞隻的泄殖腔、喉頭及場內蛋表面之微生物，分析項目包括總生菌數、沙門氏菌及志賀氏菌的盛行率。結果發現，沙門氏菌普遍存在於兩種飼養模式中(10~60%檢出率)。統進統出雞舍中年老雞隻本身及其所處環境之微生物衛生指標劣於三個月後採樣時所置換的年輕雞隻；多雞齡飼養之微生物衛生指標於採樣期間無明顯變化，但優於統進統出飼養模式下之年老雞隻組別(p<0.05)。兩飼養模式產蛋率與死亡率也都相當不穩定。綜上所述，統進統出飼養管理模式，需定期徹底執行生物安全防治措施，才能提供完整統進統出經營條件，以維持良好微生物衛生安全狀態。

The operation of the all-in and all-out (AIAO) practice of laying hen farms have achieved excellent management efficiency, which has become a global trend in the egg production industry. It can reduce the chance of pathogen contamination in chickens and eggs and reduce the risk of food poisoning to ensure food safety. However, Taiwan has not fully implemented the AIAO housing practice for laying hens, and the average breeder does not know how to correctly implement this management system, which also diminished the expected benefits. Therefore, this research aims to investigate the differences between the AIAO and multi-age laying hen management practices from the microbiological hygiene perspective and to clarify whether the farmers operate under the AIAO housing practice can get the benefits from this housing practice by lowering the death rate of laying hens and increase the production rate of eggs. This research took place at two laying hen houses located in the southern part of Taiwan owned by the same business manager. However, one of the buildings was operated under the AIAO system, and the other was the multi-age housing practice. Microorganisms in two buildings were collected from the feed trough, the drinking fountain, the bottom of the laying cages, the chicken cloaca, the throat, and the eggs in the building. Samples were analyzed for the amount of total bacterial and the prevalence of Salmonella sp. and Shigella sp. Salmonella sp. was constantly being detected in two laying hen management systems (prevalence 10~60%). The results also showed that in the AIAO laying hen house, the microbiological hygiene indicators of the old laying hens (135 weeks old) and their living environment were inferior to those young laying hens (68 weeks old), which scheduled to replace the old laying hens three months before the time of sampling ( p < 0.05). In addition, there was no statistical difference between the samples collected from two different time points of the multi-age farming practice in terms of the microbiological hygiene indicators ( p < 0.05). The microbiological hygiene indicators of the multi-age practice were also better than those of the old chickens raised under the AIAO housing system (p < 0.05). Besides, the egg production rate and death rate of laying hens were extremely unstable in two of the farm management systems. In summary, the AIAO housing system for laying hens should not only focus on what so-called “chickens into the farm simultaneously and removed at the same time.” It is necessary to regularly implement biosafety prevention and control measures to comply with the AIAO management conditions and maintain good microbial health and safety.