Kimberly J. Reuscher, Nigel B. Cook, Courtney E. Halbach, M. Mondaca, J. V. Van Os
{"title":"商业化奶牛场稳定的牛舍气流速度与奶牛躺卧时间变化较小有关","authors":"Kimberly J. Reuscher, Nigel B. Cook, Courtney E. Halbach, M. Mondaca, J. V. Van Os","doi":"10.3389/fanim.2024.1422937","DOIUrl":null,"url":null,"abstract":"Heat stress is a known challenge for dairy farms, but standardized, practical heat abatement assessments are lacking. Our objectives were to evaluate the summer ventilation system performance of Wisconsin freestall facilities, provide farms with feedback, and refine our assessment method for knowledge transfer to the industry. Six naturally ventilated (NV) and six cross-ventilated (CV) facilities (n=12) were enrolled. On day 1, 30 focal cows received data loggers to measure resting behavior and intravaginal temperature. Data loggers recorded barn air temperature and relative humidity. Air speeds (AS) were measured manually with anemometers to characterize AS distributions at cow resting (0.5m) and standing (1.5m) heights. Data loggers were removed on day 5, resulting in 3 days of data for resting behavior, vaginal temperature, and temperature humidity index (THI). The fixed effects of average AS and daily maximum THI on daily maximum vaginal temperature (VT), 24-h lying time (LT), and the number and duration of daily lying bouts were analyzed using linear mixed models. We evaluated the fixed effects of THI, average AS, and within-facility SD in AS among stalls on within-facility SD of VT, LT, and the number and duration of lying bouts among focal cows. Stall AS in NV vs. CV barns was 1.4 ± 0.3 vs. 2.0 ± 0.7 m/s (inter-facility ranges: 0.9–1.7 vs. 1.4–3.1 m/s) at resting height and 2.3 ± 0.3 vs. 2.5 ± 0.5 m/s (range: 1.7–2.8 vs. 1.7–3.1 m/s) at standing height. When facility AS increased by 1 m/s, cows had 0.8 fewer lying bouts per day. When the within-facility SD of AS among stalls increased by 1 m/s, the SD among cows of daily lying time increased 1 h/d, driven by an increase in the SDs of lying bouts (+2.5 bouts/d) and durations (13.9 min/bout). For every 10-unit increase in THI, VT increased 0.4°C, daily lying bouts tended to increase by 0.9/d, and SD of daily lying time increased 0.4 h/d. The farms received reports with summary data and suggestions to improve the consistency of AS at cow resting height. Consistent air speeds of ≥1 m/s among stalls can improve cow comfort during heat stress by reducing variation in lying behavior.","PeriodicalId":503755,"journal":{"name":"Frontiers in Animal Science","volume":"9 2","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Consistent stall air speeds in commercial dairy farms are associated with less variability in cow lying times\",\"authors\":\"Kimberly J. Reuscher, Nigel B. Cook, Courtney E. Halbach, M. Mondaca, J. V. Van Os\",\"doi\":\"10.3389/fanim.2024.1422937\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Heat stress is a known challenge for dairy farms, but standardized, practical heat abatement assessments are lacking. Our objectives were to evaluate the summer ventilation system performance of Wisconsin freestall facilities, provide farms with feedback, and refine our assessment method for knowledge transfer to the industry. Six naturally ventilated (NV) and six cross-ventilated (CV) facilities (n=12) were enrolled. On day 1, 30 focal cows received data loggers to measure resting behavior and intravaginal temperature. Data loggers recorded barn air temperature and relative humidity. Air speeds (AS) were measured manually with anemometers to characterize AS distributions at cow resting (0.5m) and standing (1.5m) heights. Data loggers were removed on day 5, resulting in 3 days of data for resting behavior, vaginal temperature, and temperature humidity index (THI). The fixed effects of average AS and daily maximum THI on daily maximum vaginal temperature (VT), 24-h lying time (LT), and the number and duration of daily lying bouts were analyzed using linear mixed models. We evaluated the fixed effects of THI, average AS, and within-facility SD in AS among stalls on within-facility SD of VT, LT, and the number and duration of lying bouts among focal cows. Stall AS in NV vs. CV barns was 1.4 ± 0.3 vs. 2.0 ± 0.7 m/s (inter-facility ranges: 0.9–1.7 vs. 1.4–3.1 m/s) at resting height and 2.3 ± 0.3 vs. 2.5 ± 0.5 m/s (range: 1.7–2.8 vs. 1.7–3.1 m/s) at standing height. When facility AS increased by 1 m/s, cows had 0.8 fewer lying bouts per day. When the within-facility SD of AS among stalls increased by 1 m/s, the SD among cows of daily lying time increased 1 h/d, driven by an increase in the SDs of lying bouts (+2.5 bouts/d) and durations (13.9 min/bout). For every 10-unit increase in THI, VT increased 0.4°C, daily lying bouts tended to increase by 0.9/d, and SD of daily lying time increased 0.4 h/d. The farms received reports with summary data and suggestions to improve the consistency of AS at cow resting height. 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引用次数: 0
摘要
热应激是奶牛场面临的一个众所周知的挑战,但却缺乏标准化、实用的防暑降温评估。我们的目标是评估威斯康星州自由牧场夏季通风系统的性能,为牧场提供反馈意见,并改进我们的评估方法,以便向业界传授知识。六个自然通风(NV)设施和六个交叉通风(CV)设施(n=12)参加了评估。第 1 天,30 头重点奶牛接受了数据记录仪,以测量休息行为和阴道内温度。数据记录器记录牛舍空气温度和相对湿度。风速(AS)由风速计手动测量,以确定奶牛休息(0.5 米)和站立(1.5 米)高度的 AS 分布特征。第 5 天移除数据记录器,从而获得 3 天的休息行为、阴道温度和温湿度指数(THI)数据。我们使用线性混合模型分析了平均AS和日最大温湿度指数对日最高阴道温度(VT)、24小时卧床时间(LT)以及日卧床次数和持续时间的固定效应。我们评估了THI、平均AS以及不同牛舍间AS的设施内SD对VT、LT的设施内SD以及病灶奶牛的卧姿次数和持续时间的固定效应。NV牛舍与CV牛舍的牛舍AS在静止高度为1.4 ± 0.3 vs. 2.0 ± 0.7 m/s(设施间范围:0.9-1.7 vs. 1.4-3.1 m/s),在站立高度为2.3 ± 0.3 vs. 2.5 ± 0.5 m/s(范围:1.7-2.8 vs. 1.7-3.1 m/s)。当设施AS增加1米/秒时,奶牛每天的卧地次数减少0.8次。当栏舍内AS的SD增加1米/秒时,奶牛每天躺卧时间的SD增加了1小时/天,这主要是躺卧阵数(+2.5阵/天)和持续时间(13.9分钟/阵)的SD增加所致。THI每升高10个单位,VT升高0.4°C,日卧次增加0.9次/天,日卧时SD增加0.4小时/天。奶牛场收到的报告中包括汇总数据和提高奶牛静卧高度时AS一致性的建议。牛舍间气流速度≥1 m/s的一致性可减少卧地行为的变化,从而提高奶牛在热应激期间的舒适度。
Consistent stall air speeds in commercial dairy farms are associated with less variability in cow lying times
Heat stress is a known challenge for dairy farms, but standardized, practical heat abatement assessments are lacking. Our objectives were to evaluate the summer ventilation system performance of Wisconsin freestall facilities, provide farms with feedback, and refine our assessment method for knowledge transfer to the industry. Six naturally ventilated (NV) and six cross-ventilated (CV) facilities (n=12) were enrolled. On day 1, 30 focal cows received data loggers to measure resting behavior and intravaginal temperature. Data loggers recorded barn air temperature and relative humidity. Air speeds (AS) were measured manually with anemometers to characterize AS distributions at cow resting (0.5m) and standing (1.5m) heights. Data loggers were removed on day 5, resulting in 3 days of data for resting behavior, vaginal temperature, and temperature humidity index (THI). The fixed effects of average AS and daily maximum THI on daily maximum vaginal temperature (VT), 24-h lying time (LT), and the number and duration of daily lying bouts were analyzed using linear mixed models. We evaluated the fixed effects of THI, average AS, and within-facility SD in AS among stalls on within-facility SD of VT, LT, and the number and duration of lying bouts among focal cows. Stall AS in NV vs. CV barns was 1.4 ± 0.3 vs. 2.0 ± 0.7 m/s (inter-facility ranges: 0.9–1.7 vs. 1.4–3.1 m/s) at resting height and 2.3 ± 0.3 vs. 2.5 ± 0.5 m/s (range: 1.7–2.8 vs. 1.7–3.1 m/s) at standing height. When facility AS increased by 1 m/s, cows had 0.8 fewer lying bouts per day. When the within-facility SD of AS among stalls increased by 1 m/s, the SD among cows of daily lying time increased 1 h/d, driven by an increase in the SDs of lying bouts (+2.5 bouts/d) and durations (13.9 min/bout). For every 10-unit increase in THI, VT increased 0.4°C, daily lying bouts tended to increase by 0.9/d, and SD of daily lying time increased 0.4 h/d. The farms received reports with summary data and suggestions to improve the consistency of AS at cow resting height. Consistent air speeds of ≥1 m/s among stalls can improve cow comfort during heat stress by reducing variation in lying behavior.