Automatic gravimetric calorimeter with simultaneous recording of physical activity for poultry.

An automatic calorimeter, based on gravimetric principles, for studies on the energy metabolism of the fowl, with simultaneous recording of the physical activity, is described. In order to reduce errors in the determination of heat production to below 3% a three hour experimental period is necessary. The length of this period in comparison to that of the Pettenkofer system is discussed. The relation between heat production and physical activity shows a good fit in a linear regression equation, from which resting heat production is derived. Up to 25% of the total heat production is related to physical activity, mainly during the day-time.