Department of Animal Science, University of Minnesota, St. Paul 55108.
Animal Welfare Program, University of British Columbia, Vancouver, BC, Canada V6T 1Z4.
J Dairy Sci. 2017 Jul;100(7):5675-5686. doi: 10.3168/jds.2016-12501. Epub 2017 Apr 27.
Automated calf feeding systems are becoming more common on US dairy farms. The objective of this study was to evaluate calf health in these systems and to identify risk factors associated with adverse health outcomes on farms in the Upper Midwest United States. Over an 18-mo period on bimonthly farm visits to 38 farms, calves (n = 10,179) were scored for attitude, ear, eye, and nasal health, as well as evidence of diarrhea (hide dirtiness score of perianal region, underside of the tail, and tailhead). For all health score categories, a score of 0 represented an apparently healthy animal. Rectal temperatures were taken in calves scoring a ≥2 in any category, and those with a temperature >39.4°C were categorized as having a fever (n = 550). Associations were determined between farm-level variables and health scores to identify risk factors for higher (worse) scores. All health outcomes were associated with season of measurement, with fall and winter seasons increasing the odds of a high health score or detected fever. High bacterial counts measured in the milk or milk replacer were associated with increased odds for higher attitude and ear scores, and higher odds for calves having a detected fever. Higher peak milk allowance (L/d) was associated with lower hide dirtiness score, whereas a longer period of time (d) to reach peak milk allowance was associated with increased odds of higher scores for attitude, ear, eye, and hide dirtiness, as well as fever. Higher fat content in milk was associated with increased odds of high eye score. Less space per calf (m/calf) was associated with higher ear and eye scores, whereas larger group sizes were associated with increased odds of higher nasal score and decreased odds of higher hide dirtiness score. Rectangular pen shape was associated with decreased odds of higher eye score. Absence of a positive pressure ventilation tube was associated with increased odds of having a calf detected with a fever. Based on these results, we hypothesize that these factors could be managed to improve health outcomes for dairy calves on automated feeding systems.
自动化犊牛喂养系统在美国奶牛场越来越普遍。本研究旨在评估这些系统中的犊牛健康状况，并确定与美国中西部高地农场不良健康结果相关的风险因素。在 18 个月的时间里，每两个月对 38 个农场进行一次农场访问，对 10179 头犊牛的态度、耳朵、眼睛和鼻腔健康以及腹泻情况（肛周区域、尾巴下方和尾巴头部的污垢评分）进行评分。对于所有健康评分类别，0 分表示动物显然健康。在任何类别中评分≥2 的犊牛中测量直肠温度，体温>39.4°C 的犊牛归类为发热（n=550）。确定农场级别的变量与健康评分之间的关联，以确定更高（更差）评分的风险因素。所有健康结果均与测量季节相关，秋季和冬季增加了高健康评分或检测到发热的可能性。牛奶或代乳粉中测量的高细菌计数与更高的态度和耳朵评分以及检测到发热的可能性增加相关。较高的峰值牛奶允许量（L/d）与较低的污垢评分相关，而达到峰值牛奶允许量的时间（d）较长与更高的态度、耳朵、眼睛和污垢评分以及发热的可能性增加相关。牛奶中的脂肪含量较高与高眼睛评分的可能性增加相关。每头犊牛的空间（m/犊牛）较少与耳朵和眼睛评分较高相关，而较大的群体大小与更高的鼻腔评分和较低的污垢评分较高的可能性增加相关。矩形畜栏形状与较低的眼睛评分较高的可能性相关。没有正压通风管与检测到发热的犊牛的可能性增加相关。根据这些结果，我们假设可以管理这些因素以改善自动化喂养系统中犊牛的健康结果。
