Microbes play key roles in animal welfare and food safety but there is little understanding of whether microbiomes associated with livestock vary in space and time. Here we analysed the bacteria associated with the carcasses of the same breed of 28 poultry broiler flocks at different stages of processing across two climatically similar UK regions over two seasons with 16S metabarcode DNA sequencing. Numbers of taxa types did not differ by region, but did by season (P = 1.2 × 10⁻¹⁹), and numbers increased with factory processing, especially in summer. There was also a significant (P < 1 × 10⁻⁴) difference in the presences and abundances of taxa types by season, region and factory processing stage, and the signal for seasonal and regional differences remained highly significant on final retail products. This study therefore revealed that both season and region influence the types and abundances of taxa on retail poultry products. That poultry microbiomes differ in space and time should be considered when testing the efficacy of microbial management interventions designed to increase animal welfare and food safety: these may have differential effects on livestock depending on location and timing.

微生物在动物福利和食品安全中发挥着关键作用，但很少有人了解与牲畜相关的微生物组是否在空间和时间上有所不同。在这里，我们通过 16S 元条形码 DNA 测序，在两个气候相似的英国地区两个季节的不同加工阶段分析了与同一品种的 28 只家禽肉鸡的屠体相关的细菌。分类群类型的数量不因地区而异，但因季节而异（P = 1.2 × 10 ^-19），并且数量随着工厂加工而增加，尤其是在夏季。还有一个显着的（P < 1 × 10 ^-4) 按季节、地区和工厂加工阶段分类群类型的存在和丰度的差异，以及季节性和地区差异的信号在最终零售产品上仍然非常显着。因此，这项研究表明，季节和地区都会影响零售家禽产品分类群的类型和丰度。在测试旨在增加动物福利和食品安全的微生物管理干预措施的有效性时，应考虑家禽微生物群在空间和时间上的不同：这些可能对牲畜产生不同的影响，具体取决于地点和时间。