Department of Clinical Science, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC, Canada J2S 2M2.
Lactanet, Sainte-Anne-de-Bellevue, QC, Canada H9X3R4.
J Dairy Sci. 2024 Sep;107(9):7276-7285. doi: 10.3168/jds.2024-24700. Epub 2024 May 31.
The objective of this study was to examine the influence of different environmental factors on ATP luminometry measurements of feeding equipment and to investigate associations with health of preweaning calves and the levels of ATP identified through luminometry. On 50 commercial dairy farms in Quebec, Canada, ATP luminometry measurements (in relative light units, RLU) were obtained using the direct swabbing technique with Hygiena UltraSnap swabs and a liquid rinsing technique with the same swab for automatic milk feeders (AMF), bottles, buckets, esophageal tube feeders (ET), milk replacer, nipples, and water. During this visit, environmental factors (including temperature, air draft, humidity, ammonia, and bacterial count) were collected, and a clinical examination (including respiratory score and fecal score) was performed for all preweaning calves present at the farm. This process was repeated 4 times in a year, leading to collection of luminometer results, environmental parameters, and overall health of calves for each season per farm. Overall, a difference in luminometer results was seen between the different periods sampled for all feeding equipment (except the ET), milk replacer, and water, showing higher RLU values in spring and summer and lower values in autumn and winter. When comparing RLU measurements with environmental factors, only a low to negligible correlation could be found. When feeding equipment was classified as not contaminated or contaminated based on previously described cutoff values, a good agreement within a farm for the different seasons was noticed only for nipples (Gwet's agreement AC1 = 0.64), with a poor to moderate agreement for other feeding equipment. Regarding the different models of nipples, Peach Teat nipples showed higher RLU values compared with Merrick's nipples. An association was seen between the proportion of preweaning calves suffering from diarrhea on the farm and the contamination of AMF based on ATP luminometry (logistic regression estimate = 0.52). For other feeding equipment, milk replacer, and water, no significant associations were found. This study showed that ATP luminometry measurements of feeding equipment from preweaning calves are susceptible to seasonality and type of nipple. Thus, these factors should be taken into consideration when interpreting results. Additionally, an association could be made between diarrhea in preweaning calves and the contamination of AMF based on ATP luminometry, showing the potential clinical importance of this on-farm hygiene assessment tool.
本研究旨在探讨不同环境因素对喂养设备 ATP 发光测定的影响，并研究其与断奶前犊牛健康和发光测定中鉴定的 ATP 水平之间的关系。在加拿大魁北克的 50 个商业奶牛场，使用 Hygiena UltraSnap 拭子的直接擦拭技术和相同拭子的液体冲洗技术，对自动奶料器（AMF）、奶瓶、桶、食管管饲器（ET）、代乳料、奶嘴和水进行 ATP 发光测量（以相对光单位，RLU 表示）。在此访问期间，收集了环境因素（包括温度、气流、湿度、氨和细菌计数），并对农场中所有存在的断奶前犊牛进行了临床检查（包括呼吸评分和粪便评分）。每年重复进行 4 次，为每个农场的每个季节收集发光计结果、环境参数和犊牛整体健康状况。总体而言，所有喂养设备（除 ET 外）、代乳料和水的不同采样期之间的发光计结果存在差异，春季和夏季的 RLU 值较高，秋季和冬季的 RLU 值较低。当将 RLU 测量值与环境因素进行比较时，仅发现低到可以忽略不计的相关性。当根据先前描述的截止值将喂养设备分类为未污染或污染时，仅注意到不同季节的奶嘴在农场内具有良好的一致性（Gwet 的一致性 AC1=0.64），而其他喂养设备的一致性较差。对于不同型号的奶嘴，Peach Teat 奶嘴的 RLU 值高于 Merrick 奶嘴。在基于 ATP 发光法的 AMF 污染方面，观察到农场中腹泻的断奶前犊牛比例与污染之间存在关联（逻辑回归估计值=0.52）。对于其他喂养设备、代乳料和水，未发现显著关联。本研究表明，来自断奶前犊牛的喂养设备的 ATP 发光测量易受季节性和奶嘴类型的影响。因此，在解释结果时应考虑这些因素。此外，基于 ATP 发光法，腹泻的断奶前犊牛与 AMF 的污染之间存在关联，表明这种农场卫生评估工具具有潜在的临床重要性。
