Nasr Mohammed A F, El-Tarabany Mahmoud S
Animal Wealth Development Department, Faculty of Veterinary Medicine, Zagazig University, Egypt.
Animal Wealth Development Department, Faculty of Veterinary Medicine, Zagazig University, Egypt.
J Therm Biol. 2017 Feb;64:73-77. doi: 10.1016/j.jtherbio.2017.01.004. Epub 2017 Jan 17.
In Egypt, cow's milk represents 52.11% of the total milk production. Climatic condition is mainly expected to impact the welfare and productive performance of livestock animals. Thus, we aimed to explore the impact of temperature-humidity index (THI) on somatic cell count (SCC), milk production and composition on daily milk test records (33600) of Holstein cows under subtropical Egyptian conditions with different levels of THI. Our results revealed that daily milk yield and composition (fat%, protein %, yielded fat, yielded protein and the percentage of lactose) were higher in low THI (31.91kg, 3.91%, 3.22%, 418kg, 349kg and 4.20%, respectively) when compared with high THI. SCC significantly increased 36% from low to high THI. In addition to, it was increased with advanced parities 231.11% from 2nd to 7th parities. At high THI level, SCC was negatively correlated with total MY (r=-0.12P<0.05), 305 MY (r=-0.16P<0.05), protein % (r=-0.15P<0.01), fat% (r=-0.14P<0.01) and lactose % (r=-0.26P<0.01). The current study concluded that dairy cows performance was better in most of the investigated parameters at low THI than those in high THI. Thus, indicating a detrimental effect of THI on both welfare and economic return.
在埃及，牛奶产量占总奶产量的52.11%。气候条件主要预计会影响家畜的福利和生产性能。因此，我们旨在探讨温度湿度指数（THI）对埃及亚热带条件下不同THI水平的荷斯坦奶牛每日牛奶检测记录（33600条）中的体细胞计数（SCC）、产奶量及成分的影响。我们的研究结果显示，与高THI相比，低THI时的日产奶量及成分（脂肪百分比、蛋白质百分比、产脂肪量、产蛋白量和乳糖百分比）更高（分别为31.91千克、3.91%、3.22%、418千克、349千克和4.20%）。SCC从低THI到高THI显著增加了36%。此外，随着胎次增加，SCC从第2胎到第7胎增加了231.11%。在高THI水平下，SCC与总产奶量（r = -0.12，P<0.05）、305天产奶量（r = -0.16，P<0.05）、蛋白质百分比（r = -0.15，P<0.01）、脂肪百分比（r = -0.14，P<0.01）和乳糖百分比（r = -0.26，P<0.01）呈负相关。当前研究得出结论，在大多数调查参数中，低THI下奶牛的性能优于高THI下的奶牛。因此，表明THI对福利和经济回报均有不利影响。
