Wilson L L, Terosky T L, Stull C L, Stricklin W R
Department of Dairy and Animal Science, The Pennsylvania State University, University Park 16802, USA.
J Anim Sci. 1999 Jun;77(6):1341-7. doi: 10.2527/1999.7761341x.
The objectives of this study were to determine effects of housing design (calves tethered in open stalls vs untethered in individual pens) and widths of 56, 66, and 76 cm (2 x 3 factorial arrangement of treatments) on indicators of stress and behavior in special-fed veal calves. Three production cycles (groups) were used, each with 36 Holstein bull calves. Calves (n = 108) were randomly allotted to treatments upon arrival at the facility. Blood samples were collected four times (wk 4, 9, 13, and 18) during the 18-wk production cycle. Blood serum values for cortisol and alpha1-acid glycoprotein (AGP) exhibited few treatment differences. Blood leukocyte differential counts at 4 and 18 wk (segmented neutrophils [N], banded neutrophils, lymphocytes [L], basophils, and the N:L ratio) were not different (P > .05) among housing designs or widths. However, there were differences (P < .05) in monocytes and eosinophils during the 28-d period after arrival; calves in stalls 76 cm wide had the greatest percentage of both leukocytes, and calves in the 66-cm stalls had the lowest monocyte percentage. Calves were recorded on videotape during wk 4, 13.5, and 18 to determine frequencies and durations of postures and behaviors (e.g., lying, standing, chewing, tongue playing, grooming, and investigative activities). There were no consistent differences (P > .05) in postures or behaviors among calves in different housing designs or widths. Calves spent approximately 71 and 31% in lying and standing positions, with no preference for the right or left side while recumbent. There was a tendency for calves in wider stalls or pens at wk 9 and 18 to exhibit more self-grooming activities. Tongue playing and investigative and chewing activities were exhibited in all treatments, but no differences (P > .05) were observed. However, calves housed in the 56-cm pens displayed difficulty in changing from lying to a standing position and were unable to extend one or more legs while recumbent. Even though there were few differences in behavioral, physiological, growth, or anatomical traits in this study, further increases in age and(or) weight of finished calves will require a reassessment of the appropriateness of individual veal calf housing design and dimensions.
本研究的目的是确定饲养设计（犊牛拴系在开放式牛栏中与不拴系在个体围栏中）以及56厘米、66厘米和76厘米的宽度（2×3析因处理安排）对特殊饲养的犊牛应激和行为指标的影响。使用了三个生产周期（组），每组有36头荷斯坦公牛犊。犊牛（n = 108）在抵达设施时被随机分配到各处理组。在18周的生产周期内采集了四次血样（第4周、第9周、第13周和第18周）。皮质醇和α1-酸性糖蛋白（AGP）的血清值几乎没有处理差异。第4周和第18周的血液白细胞分类计数（分叶中性粒细胞[N]、杆状中性粒细胞、淋巴细胞[L]、嗜碱性粒细胞以及N:L比值）在饲养设计或宽度之间没有差异（P > 0.05）。然而，在抵达后的28天内，单核细胞和嗜酸性粒细胞存在差异（P < 0.05）；76厘米宽牛栏中的犊牛这两种白细胞的百分比最高，66厘米宽牛栏中的犊牛单核细胞百分比最低。在第4周、第13.5周和第18周对犊牛进行录像记录，以确定姿势和行为（如躺卧、站立、咀嚼、舔舌、梳理毛发和探究活动）的频率和持续时间。不同饲养设计或宽度的犊牛在姿势或行为方面没有一致的差异（P > 0.05）。犊牛大约71%和31%的时间处于躺卧和站立姿势，躺卧时对右侧或左侧没有偏好。在第9周和第18周，较宽牛栏或围栏中的犊牛有表现出更多自我梳理毛发活动的趋势。所有处理组都有舔舌、探究和咀嚼活动，但未观察到差异（P > 0.05）。然而，饲养在56厘米围栏中的犊牛从躺卧姿势转变为站立姿势有困难，躺卧时无法伸展一条或多条腿。尽管本研究中行为、生理、生长或解剖特征的差异很少，但育成犊牛年龄和（或）体重的进一步增加将需要重新评估个体犊牛饲养设计和尺寸的适宜性。
