Macaulay A S, Hahn G L, Clark D H, Sisson D V
USDA, ARS, Meat Animal Research Center, Clay Center, NE 68933-1066, USA.
J Dairy Sci. 1995 Apr;78(4):856-62. doi: 10.3168/jds.S0022-0302(95)76698-X.
During fall, 30 Holstein calves were randomly assigned to three housing treatments from birth to weaning: conventional wooden hutches, enclosed molded polyethylene domes, and thermomolded opaque polymer hutches with ridge-top ventilation systems. The wooden and polymer hutches had outdoor pens. Fifteen calves, 5 in each housing type, were fitted with portable data loggers to record ambient (calf microclimate) and tympanic temperatures. Additional data collected included weekly girth, BW, and feed intake; blood samples were collected within 24 h of birth and at weaning (8 wk); and behavioral observations were made at 1, 4, and 7 wk of age. Polyethylene domes had the warmest microclimate, followed by wooden and polymer hutches. Feed intake, growth measurements, blood physiology, and behavior were unaffected by housing type. Diurnal tympanic temperature rhythms of neonatal dairy calves in this study were monophasic: maximums were at 1200 to 1700 h, and minimums were at 0600 to 0900 h. Computed fractal dimensions of tympanic temperature by week indicated a gradual diminishing of stress as the calves became older and acclimated to their environment. This objective characterization provides a basis for further evaluation of physiological stress and a means of improving environmental management.
秋季期间，30头荷斯坦犊牛从出生到断奶被随机分配到三种饲养处理方式：传统木制犊牛栏、封闭式模制聚乙烯穹顶以及带有脊顶通风系统的热成型不透明聚合物犊牛栏。木制和聚合物犊牛栏设有室外围栏。15头犊牛，每种饲养类型5头，佩戴便携式数据记录器以记录环境温度（犊牛微气候）和鼓膜温度。收集的其他数据包括每周的胸围、体重和采食量；在出生后24小时内和断奶时（8周龄）采集血样；并在1、4和7周龄时进行行为观察。聚乙烯穹顶的微气候最温暖，其次是木制和聚合物犊牛栏。采食量、生长指标、血液生理学和行为不受饲养类型的影响。本研究中新生奶牛犊的昼夜鼓膜温度节律为单相：最高温度出现在12:00至17:00，最低温度出现在06:00至09:00。按周计算的鼓膜温度分形维数表明，随着犊牛年龄增长并适应环境，应激逐渐减轻。这种客观表征为进一步评估生理应激提供了基础，并为改善环境管理提供了一种方法。
