The effects of providing shade to lactating dairy cows in a temperate climate
The effects of providing shade to lactating dairy cows in a temperate climate
复制标题
DOI：
10.1016/j.livsci.2006.02.004
复制
发表时间：
2006-08-01
影响因子：
1.8
通讯作者：
Matthews, L. R.
中科院分区：
文献类型：
--
作者：
Kendall, P. E.;Nielsen, P. P.;Matthews, L. R.
采用两期重复交叉试验设计，将4组泌乳荷斯坦奶牛（每组10头）饲养在牧场上，研究夏季人工遮荫对其阴道温度、行为和产奶量的影响。两组有树荫，另外两组在相邻的围场没有树荫，在处理转换之前的10天内。使用阴道数据记录仪记录所有动物的体温节律。测定每头奶牛的日产奶量和乳成分。在每10 d的处理期内，观察员连续记录站立不放牧、躺卧和放牧行为。从每天0800至2000小时记录遮荫使用情况。提供遮荫降低了阴道平均温度（P < 0.05）。这在1000 ~ 1500 h之间尤为明显，与没有遮荫的奶牛相比，遮荫奶牛阴道温度的升高显著（P < 0.001）降低。遮荫对阴道最高、最低温度及阴道温度节律幅度无显著影响（P < 0.05）。有阴凉处的奶牛主要在下午三点左右使用阴凉处（P < 0.001），而没有阴凉处的奶牛在这个时候凝视的时间更长（P < 0.001）。24 h放牧、不放牧和躺卧总时间在不同处理间无显著差异（P < 0.05）。遮荫处理的奶牛产奶量高于未遮荫处理的奶牛（P < 0.05），但对乳成分没有影响（P < 0.05）。这些数据表明，在新西兰夏季条件下，提供遮荫是减少奶牛热负荷的有效方法，此外，还可能提高日产奶量。尽管只有温和的夏季条件，但与遮荫奶牛相比，未遮荫奶牛的阴道温度在下午三点左右升高，但并未对潜在的昼夜体温节律造成显著破坏。(c) 2006 Elsevier B.V.版权所有
in a two-period replicated crossover design, four groups of lactating Holstein Friesian dairy cows (n = 10 per group) were kept on pasture to investigate the effects of providing artificial shade in summer on their vaginal temperature, behaviour and milk production. Two groups had access to shade and two groups in adjacent paddocks had no shade for a 10-day period before the treatments were switched. The body temperature rhythm was recorded in all animals using vaginal data loggers. Daily milk yield and milk composition was measured for each cow. Standing without grazing, lying and grazing behaviour was recorded continuously by observers for two 24-h periods during each 10-day treatment period. Shade use was recorded daily from 0800 to 2000 h. The provision of shade reduced (P < 0.05) mean vaginal temperature. This was particularly evident between 1000 and 1500 h, when the increase in vaginal temperature was significantly (P < 0.001) lower in shaded cows compared to cows without shade. No effect of shade (P > 0.05) on the maximum and minimum vaginal temperature, or the amplitude of the vaginal temperature rhythm was found. Cows with access to shade preferred (P < 0.001) using it mainly during the mid-afternoon, while, in contrast, cows with no shade gazed more (P < 0.001) at this time. The total time spent grazing, standing without grazing and lying per 24 h did not differ (P > 0.05) between treatments. Milk production was higher (P < 0.05) in cows that had access to shade compared to those without, but milk composition was not affected (P > 0.05) by shade treatment. These data suggest that the provision of shade is an effective method to reduce heat load in dairy cows under New Zealand summer conditions and, in addition, may increase daily milk yield. Despite only mild summer conditions, vaginal temperature was elevated during the mid-aftentoon in non-shaded cows but did not cause a significant disruption in the underlying circadian body temperature rhythm compared to shaded cows. (c) 2006 Elsevier B.V. All rights reserved.