The Effects of Seasons (Hot/Dry and Cool/Humid) on Thermoregulatory Responses of Male and Female Bali-Cattle Working in the Field

A study was conducted on the effects of ploughing on physiological responses of male and female Bali-cattle. A $2{\times}2{\times}6{\times}8$ factorial design (2 seasons, 2 sexes, 6 days and 8 consecutive time of measurements every 30 minutes) was employed. Responses during the cool/humid season were lower than hot/dry; respiration rate (RR) was 52 vs 75/min, rectal temperature(RT) was 39.1 vs $39.5^{\circ}C$ and skin temperature (ST) was 37.1 vs $37.6^{\circ}C$. Within sexes, males were less tolerant than females in that their RR (66 vs 61 breath/min), RT (39.4 vs $39.2^{\circ}C$) and ST (37.6 vs $37.1^{\circ}C$) were each higher than females during work. With increasing time, during the average 2.5 h working period gradual increases in RR, RT and ST were recorded and the overall increases of 84 breath/min, $1.9^{\circ}C$ and $13.8^{\circ}C$ respectively (p < 0.001). Packed cell volume (PCV) data indicated significant difference between sexes, time and season (p < 0.001, p < 0.05 and p < 0.001 respectively). Within time (before and after 2.5 h working) the PCV decreased from 27.4 to 25.6%.