RESUMEN
The effect of washing frequency on the physiological responses and performance of buffalo calves was studied in hot summer. Thirty Nili-Ravi calves aged 4-6 months were divided into three uniform groups of ten. The calves of group A, B and C were washed two (9 a.m. and 3 p.m.), three (8 a.m., 12 noon and 4 p.m.) and four (8 a.m., 11 a.m., 2 p.m. and 5 p.m.) times in a day, respectively. They were washed with water for 5 min at a stretch. The mean linear body measurements, body weight, dry matter intake through concentrate, green fodder and physiological responses, i.e. rectal temperature, pulse rate and respiration rate before and after washing under different daily washing frequency were recorded fortnightly. The average daily gain was also calculated. The mean total dry matter intake was increased with the increase frequency of washing. The maximum mean daily body weight gain was recorded in group C followed by group B and A. There were statistically significant (P < 0.05) differences between the three washing groups. Calves were more comfortable with increase number of washing in a day in hot summer. The rectal temperature, pulse rate and respiration rate also varied significantly (P < 0.05) between the three experiment groups. It can be concluded that daily four times washing in hot summer had more beneficial effects over three and two times washing of young Nili-Ravi buffalo calves to decrease rectal temperature, pulse rate and respiration rate and to increase average feed utilization and daily gain under tropical climate.