Anzures Filiberto, Gaytán Leticia, Macías-Cruz Ulises, Avendaño-Reyes Leonel, García José E, Mellado Miguel
Department of Animal Nutrition, Autonomous Agrarian University Antonio Narro, 25315, Saltillo, Coahuila, Mexico.
Department of Veterinary Science, Autonomous Agrarian University Antonio Narro, 27054, Torreon, Mexico.
Trop Anim Health Prod. 2019 Jun;51(5):1253-1257. doi: 10.1007/s11250-019-01819-z. Epub 2019 Jan 30.
This study was conducted to evaluate the effects of hair coat characteristics on thermophysiological variables and body surface temperatures (BST), measured with infrared thermography, as well as milk yield of Holstein cows in a hot environment. Physiological and milk yield variables were assessed using 103 pluriparous Holstein cows. Also, hair angle (HA), density of hair coat (D), diameter of hair (HD), hair length (HL), weight of hair coat (Wt), and coat thickness (CT) were recorded. Biplot analysis (principal components analysis) revealed that HL was closely associated with Wt, CT, and HD and all these variables had a positive association with rectal temperature. Both CT and HL were found to be negatively associated with shoulder and neck temperature; tympanic temperature showed no association with BTS. Cows with short hair coat (length < 17 mm) did not produce more milk in 305 days than cows with longer hair coat (9673 ± 1604 vs. 9277 ± 817; P = 0.12). On the other hand, milk fat percentage at the middle of lactation was higher (P < 0.01) in cows with longer hair relative to cows with coat hair < 17 mm (3.71 vs. 3.35%, respectively). In conclusion, physical characteristics of the coat of Holstein cows were not associated with the 305-day milk yield but cows with longer hair produced a greater milk fat percentage at the middle of lactation compared to cows with short hair.
本研究旨在评估在炎热环境下，奶牛被毛特征对热生理变量、通过红外热成像测量的体表温度（BST）以及荷斯坦奶牛产奶量的影响。使用103头经产荷斯坦奶牛评估生理和产奶量变量。此外，记录了毛角（HA）、被毛密度（D）、毛发直径（HD）、毛长（HL）、被毛重量（Wt）和被毛厚度（CT）。双标图分析（主成分分析）表明，HL与Wt、CT和HD密切相关，所有这些变量与直肠温度呈正相关。发现CT和HL均与肩部和颈部温度呈负相关；鼓膜温度与BTS无关联。被毛短（长度<17毫米）的奶牛在305天内的产奶量并不比被毛长的奶牛多（9673±1604对9277±817；P=0.12）。另一方面，泌乳中期的乳脂率在被毛长的奶牛中更高（P<0.01），相对于被毛长度<17毫米的奶牛（分别为3.71%对3.35%）。总之，荷斯坦奶牛被毛的物理特征与305天产奶量无关，但与被毛短的奶牛相比，被毛长的奶牛在泌乳中期产生的乳脂率更高。
