Maintenance energy of buffaloes in different environmental temperatures.

将3头水牛和3头荷斯坦奶牛放在气候实验室中饲养7天，恒温为30ﾟC(60%相对湿度，12L12D)，每隔3小时饲喂一次。然后，在空气温度在25~35ﾟC(平均30ﾟC，相对湿度60%，12L12D，波动条件)之间昼夜波动的房间里禁食5天。在波动条件下，水牛的产热量显著低于荷斯坦牛。相反，在恒温条件下，这两个物种之间的s13EA没有显著差异。当气温从25ﾟC(0：00)升高到35ﾟC(12：00)时，荷斯坦牛的呼吸速率、呼吸量和产热量几乎同时增加，而直肠温度几乎保持不变。水牛的呼吸频率、呼吸量和产热量在前6小时没有增加，在此期间，直肠温度随着气温的升高而升高了13个百分点。这些结果表明，水牛通过在早晨气温上升时将热量储存在身体内，将呼吸维持在相当低的水平。水牛的这种热稳定性可能与S在气温日变化过程中不进行呼吸运动有关，从而有助于这种动物的节能特性。

Three buffalo-cows and three Holstein cows were maintained in a climatized laboratory(Zootron, NIAI) for 7days at constant temperature of 30ﾟC(60%RH,12L12D) and fed every 3hours(constant condition). Then, they were fasted for 5days in the room where13EA\ : the air temperature fluctuated diurnally between 25 and 35ﾟC(average 30ﾟC, 60%RH, 12L12D, fluctuating condition). Under the fluctuating condition, heat productions in buffaloes were significantly lower than those in Holsteins. On the contraly, no s13EA\ : ignificant difference was observed between the two species in the constant temperature. when air temperature increased from 25ﾟC(0 : 00) to 35ﾟC(12 : 00), the respiration rate, respiratory volume and heat production in Holsteins increased almost sim13EA\ : ultaneously, while the rectal temperature in this species was almost constant. In the other hand, respiration rate, respiratory volume and heat production in buffaloes did not increased first 6hours, duing which rectal temperature increased associat13EA\ : ed with the increase of air temperature. These results indicate that buffaloes maintain their respiration at a fairly low level by storing heat within their body mass when the air temperature increases in the morning. This thermolability in buffaloe13EA\ : s may contribute to the energy saving characteristics of this animal by refraining the respiratory exercise in the course of diurnal changes of air temperature.