Abstract
Observations in the shed were made for 3 years on groups of cattle and buffaloes of both sexes for pulse rate, respiration rate, rectal temperature and haemoglobin level during the summer months under low and high humid conditions. The average figures for these physiological reactions were always less for buffaloes than for cattle under both dry and humid conditions. Under high humidity conditions cattle cows showed a significant increase in the pulse rate and decrease in rectal temperature whereas respiration rate remained unchanged. In the buffalo cows these physiological reactions showed less change. In both the haemoglobin level was significantly lower during the rainy season. On exposure to direct sun, the buffalo reacted very badly; the Iberia index was 88 for cattle and 61 for buffalo. Because of the smaller variation in the physiological reactions due to increase in humidity at higher temperature in buffaloes (85–93° F.), this species may be considered a better dairy animal than cattle in humid tropical zones if they are protected from direct sun, which can be easily done by altering the time of grazing from day to night.