| Abstract | The objective of this study was to investigate how the bullocks perform in terms of speed, power developed and work output as a function of their
body size, draft, duration of work and climate. Four pairs of Hallikar bullocks of different average body weights were selected. These four pairs
of bullocks, five levels of draft and three levels of climate (cold, hot and warm and humid) were used to formulate a Randomized Complete Block design
experiment. Duration of work was six hours and was considered as a sub-plot factor. The responses measured were the speed, respiration and pulse rates of bullocks at intervals of one hour. It was found that the bullocks could pull maximum drafts of 13 to 16 percent of their body weight for six hours. Their average speed, power and work
output in a six-hour working day were 3 km ph, 0.91 hp per pair and 5.23 hp hours per pair. Their performance was, however, found to depend on their body size, draft, duration of work and climate. The body weight was found to be a better measure of their size than their body dimensions. The Temperature Humidity Index was found to represent climate fairly well.
At increased draft, the speed decreased but power and work· output increased. At higher drafts, the bullocks were not able to work for as long as they could at lighter drafts. The speed, power and work output increased with body weight. The increase in work output was 1.57 hp-hour per pair for an increase of 100 kg body weight per animal. The bullocks' performance was better in cold climate than in hot or warm and humid climates. Their speed and power decreased with duration of work. In six hours, the decrease was about one fourth of the initial speed and power. Relationships were developed to predict speed, power and work
output of bullocks body weight, draft, duration of work and Temperature Humidity Index (THI). The respiration and pulse rates of bullocks increased during work. The increase was rapid in the first hour of work and, thereafter, it was slow. The respiration rate increased with increase in draft, but the pulse
rate did not. |