Legrand A L, von Keyserlingk M A G, Weary D M
Animal Welfare Program, Faculty of Land and Food Systems, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada.
J Dairy Sci. 2009 Aug;92(8):3651-8. doi: 10.3168/jds.2008-1733.
The aim of the current study was to assess if cows preferred pasture or indoor housing, and how diurnal and environmental factors affected this preference. Lactating dairy cows (n = 5 groups, each containing 5 cows) were sequentially housed either in a free-stall barn on pasture, or given the choice between the 2 environments. Each group was tested 3 times under each condition, for a total of 21 d, to assess the effects of varying climatic conditions (outdoor temperature ranged from 9.9 to 28.2 degrees C and daily rainfall from 0 to 65 mm/d over the course of the experiment). When provided the choice, cows spent on average (+/- SD) 13.0 +/- 0.6 h/d on pasture, mainly at night. The time cows spent on pasture during the day decreased with the temperature-humidity index (R(2) = 0.55); time on pasture at night decreased with rainfall (R(2) = 0.12). When provided a choice, cows spent more of their lying time on pasture (69.4 +/- 0.02% of the total lying time/d) than indoors in the free-stalls. Cows also spent more time in total lying down when provided a choice than when confined to pasture [0.6 h/d more lying time; standard error of the difference (SED) = 0.21 h/d] and spent even more time lying down when confined indoors (1.1 h/d more time; SED = 0.21 h/d). Cows used the indoor housing especially for feeding; feeder use peaked when cows returned from morning and afternoon milkings. However, cows with free access to pasture spent 1.0 h/d (SED = 0.09 h/d) less time eating the TMR available indoors, resulting in a decline in intake of 2.9 kg of dry matter/d (SED = 0.36 kg of dry matter/d). How cows used the indoor housing differed when cows were provided a choice; for example, cows spent a greater percentage of their time indoors at the feed alley both during the day (47% of the total time spent indoors, versus 41% for cows confined indoors, SED = 0.02%) and at night (22 vs. 5%, SED = 0.04%). In conclusion, under the housing and environmental conditions tested, cows showed a strong preference for access to pasture at night and for access to indoor housing during the day when temperature and humidity increased.
本研究的目的是评估奶牛更喜欢牧场还是室内圈舍，以及昼夜和环境因素如何影响这种偏好。泌乳奶牛（n = 5组，每组5头）被依次安置在牧场的自由牛舍中，或者在两种环境之间进行选择。每组在每种条件下测试3次，共21天，以评估不同气候条件的影响（实验过程中室外温度范围为9.9至28.2摄氏度，日降雨量为0至65毫米/天）。当可以选择时，奶牛平均每天（±标准差）在牧场停留13.0±0.6小时，主要是在夜间。奶牛白天在牧场停留的时间随温湿度指数下降（R² = 0.55）；夜间在牧场停留的时间随降雨量下降（R² = 0.12）。当可以选择时，奶牛躺卧时间中在牧场的比例（占每天总躺卧时间的69.4±0.02%）高于在室内自由牛舍。当可以选择时，奶牛总的躺卧时间也比只限制在牧场时更多[多躺卧0.6小时/天；差异标准误（SED） = 0.21小时/天]，而在室内圈养时躺卧时间更多（多1.1小时/天；SED = 0.21小时/天）。奶牛尤其在进食时使用室内圈舍；当奶牛早晚挤奶回来时，采食槽的使用达到峰值。然而，可自由进入牧场的奶牛每天在室内吃全混合日粮（TMR）的时间少1.0小时（SED = 0.09小时/天），导致干物质摄入量每天减少2.9千克（SED = 0.36千克干物质/天）。当奶牛可以选择时，它们使用室内圈舍的方式有所不同；例如，奶牛白天在采食通道室内停留的时间占其在室内总停留时间的比例更大（47%，而圈养在室内的奶牛为41%，SED = 0.02%），夜间也是如此（22%对5%，SED = 0.04%）。总之，在所测试的圈舍和环境条件下，奶牛表现出强烈的偏好，即在夜间进入牧场，在白天温度和湿度升高时进入室内圈舍。
