Egberts V, van Schaik G, Brunekreef B, Hoek G
Institute for Risk Assessment Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 2, 3584 CM, Utrecht, the Netherlands.
Epidemiology group, GD Animal Health, Postbus 9, 7400AA, Deventer, The Netherlands; Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, 3584 CM, Utrecht, the Netherlands.
Prev Vet Med. 2019 Jul 1;168:1-8. doi: 10.1016/j.prevetmed.2019.03.021. Epub 2019 Apr 3.
Extreme temperatures and air pollution are both associated with increased mortality risk in humans. However, the effects of temperature and air pollution on cattle have not been investigated much before.
Short-term effects of temperature (heat and cold) and air pollution on cattle mortality were investigated and quantified in the Netherlands during 2012-2017.
Daily data on cattle mortality, weather conditions and mean levels of particulate matter (PM), ozone (O), ammonia (NH) and nitrogen dioxide (NO) of the Netherlands during 2012-2017 were collected. Associations were investigated with time-series regression using distributed lag non-linear models including lags of up to 25 days. Effects of temperature were expressed as those associated with extreme and moderate heat or cold, defined as Temperature Humidity Index (THI) values below the 1st and 5th percentile, and above the 95th and 99th percentile of the national THI distribution. Effects of air pollutants were expressed per 10 μg/m change in daily mean concentrations.
Both high and low temperatures were associated with increased mortality amongst different age groups. For instance, the newborn calves of at most 14 days showed a cumulative relative risk (RR) of 2.13 (95%CI: 1.99-2.28) for extreme heat and the pre-weaned calves (15-55 days) showed a cumulative RR of 1.50 (95%CI: 1.37-1.64) for extreme cold. Associations of air pollution with mortality were not consistent, except for the effect of ozone of lag 0-7 and lag 0-25. Exposure to O in the newborn calves resulted in a cumulative RR of 1.09 (95%CI: 1.04-1.4) for lag 0-7 and 1.09 (95%CI: 1.03-1.16) for lag 0-25.
Both high and low temperatures were associated with increased mortality amongst pre-weaned calves of 15-55 days, whereas associations in weaned calves (56 days - 1 year) were only observed for low temperatures and in newborn calves of at most 14 days and lactating cattle >2 years only for high temperatures. Associations of air pollution with mortality in all age groups were not consistent, except for the effect of ozone of lag 0-7 and lag 0-25.
极端温度和空气污染均与人类死亡风险增加相关。然而，温度和空气污染对牛的影响此前尚未得到充分研究。
对2012年至2017年荷兰温度（炎热和寒冷）及空气污染对牛死亡率的短期影响进行调查并量化。
收集了2012年至2017年荷兰牛死亡率、天气状况以及颗粒物（PM）、臭氧（O）、氨（NH）和二氧化氮（NO）平均水平的每日数据。使用分布式滞后非线性模型进行时间序列回归分析，包括长达25天的滞后。温度影响以与极端和中度炎热或寒冷相关的影响表示，定义为温度湿度指数（THI）值低于全国THI分布的第1和第5百分位数，以及高于第95和第99百分位数。空气污染物的影响以每日平均浓度每变化10μg/m³表示。
高温和低温均与不同年龄组的死亡率增加相关。例如，最多14天的新生犊牛在极端炎热情况下的累积相对风险（RR）为2.13（95%置信区间：1.99 - 2.28），断奶前犊牛（15 - 55天）在极端寒冷情况下的累积RR为1.50（95%置信区间：1.37 - 1.64）。空气污染与死亡率的关联并不一致，除了滞后0 - 7天和滞后0 - 25天的臭氧影响。新生犊牛暴露于滞后0 - 7天的臭氧时累积RR为1.09（95%置信区间：1.04 - 1.4），滞后0 - 25天为1.09（95%置信区间：1.03 - 1.16）。
高温和低温均与15 - 55天断奶前犊牛的死亡率增加相关，而断奶犊牛（56天至1年）仅在低温时存在关联，最多14天的新生犊牛和2岁以上泌乳牛仅在高温时存在关联。空气污染与所有年龄组死亡率的关联并不一致，除了滞后0 - 7天和滞后0 - 25天的臭氧影响。
