Spore-forming bacteria, such as Paenibacillus spp. and Bacillus spp., can survive HTST pasteurization in spore form and affect the quality of dairy products (e.g., spoilage in fluid milk). With the demand for higher quality finished products that have longer shelf lives and that can be distributed further and to new markets, dairy processors are becoming interested in obtaining low-spore raw milk supplies. One method to reduce spores in the dairy system will require disrupting the transmission of spores from environmental locations, where they are often found at high concentrations (e.g., manure, bedding), into bulk tank raw milk. Previous research has suggested that cow hygiene factors (e.g., udder hygiene, level of spores in milk from individual cows) are important for the transmission of spores into bulk tank raw milk, suggesting that one potential strategy to reduce spores in bulk tank milk should target cow hygiene in the parlor. To that end, we conducted a study on 5 New York dairy farms over a 15-mo period to evaluate the effect of a combination of intervention strategies, applied together, on the levels of aerobic spores in bulk tank raw milk. The combination of interventions included (1) training milking staff to focus on teat-end cleaning during milking preparation, and (2) implementing changes in laundered towel preparation (i.e., use of detergent, chlorine bleach, and drying). Study design involved collecting bulk tank raw milk samples for a week before and a week after initiating the combination of interventions (i.e., training on the importance of teat-end cleaning and towel treatment). Observations on teat-end condition, udder hygiene scores, and number of kickoffs during milking were also collected for 24 h before and after implementation of the interventions. A total of 355 bulk tank raw milk samples were collected with mean mesophilic and thermophilic spore counts of 2.1 and 2.4 cfu/mL, respectively, before interventions were applied, and 1.6 and 1.5 cfu/mL, respectively, after the interventions were applied. These reductions represent decreases of 37 and 40% in bulk tank raw milk mesophilic spores and thermophilic spores, respectively. Importantly, spore reductions were observed during each of the 3 visits once the interventions were applied, and the largest reduction in spores was recorded for the first sampling after training the milking staff. Further, when a higher proportion of very rough teat ends was observed, bulk tank milk thermophilic spore counts were significantly higher. The intervention strategies tested here represent easy-to-execute cleaning strategies (e.g., focusing on teat-end hygiene and towel washing procedures) that can reduce bulk tank raw milk spore levels. Future studies should validate the effect of on-farm interventions for reduced spore raw milk on corresponding processed product quality and will need to verify the effects of these small changes on product shelf life.

中文翻译：

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奶牛场的挤奶时间卫生干预措施可以减少原奶中的孢子数量。

形成孢子的细菌，如Paenibacillus spp。芽孢杆菌属和芽孢杆菌属（Bacillus spp。）可以经受芽孢形式的HTST巴氏灭菌，并影响乳制品的质量（例如，液态奶变质）。随着人们对保质期更长，可以进一步分配并进入新市场的高质量成品的需求，乳制品加工企业对获得低孢子原料奶的兴趣日益浓厚。减少乳制品系统中的孢子的一种方法将需要中断孢子从环境位置的传播，环境位置通常以高浓度（例如粪便，被褥）发现它们进入散装桶装生乳。先前的研究表明，奶牛的卫生因素（例如，乳房卫生，每头奶牛的牛奶中的孢子水平）对于将孢子传播到散装原料奶中非常重要，建议减少散装罐装牛奶中的孢子的一种潜在策略应针对奶牛场的卫生。为此，我们在15个月的时间内对纽约的5个奶牛场进行了一项研究，以评估联合应用干预策略对散装罐装原奶中好氧孢子水平的影响。干预措施的组合包括（1）培训挤奶人员在准备挤奶过程中着重于乳头端清洁，以及（2）改变洗过的毛巾的准备（即使用洗涤剂，氯漂白剂和干燥剂）。研究设计涉及在采取联合干预措施之前（即，对奶头端清洁和毛巾处理的重要性进行培训），在开始前一周和之后一周收集散装储罐的原奶样品。观察奶头状况，乳房卫生评分，在实施干预之前和之后的24小时内，还收集了挤奶期间的开瓶次数和开瓶次数。在进行干预之前，总共收集了355个散装罐生乳样品，其中温和嗜热孢子计数分别为2.1和2.4 cfu / mL，而在进行干预之后，分别为1.6和1.5 cfu / mL。这些减少分别代表散装罐生乳中温孢子和嗜热孢子分别减少了37％和40％。重要的是，一旦采用干预措施，在3次就诊中每次都观察到孢子减少，并且在对挤奶人员进行培训后的第一次采样中记录到最大的孢子减少。此外，当观察到较高比例的非常粗糙的奶头时，大罐牛奶中的嗜热孢子计数明显更高。此处测试的干预策略代表易于执行的清洁策略（例如，着重于乳头端卫生和毛巾洗涤程序），可以降低散装桶中生乳孢子的水平。未来的研究应验证减少孢子原奶的农场干预对相应加工产品质量的影响，并需要验证这些微小变化对产品保质期的影响。