A Formula to Describe the Relation between Heat Production at Thermoneutral as well as below Thermoneutral Temperatures Simultaneously

Abstract

The relation between heat production and ambient temperature is mostly described by two separate linear models; one for data obtained in the zone of thermoneutrality and one for data of conditions below the thermoneutral zone. In this study a continuous model is developed to describe the relation in the thermoneutral zone and below the critical temperature (Tcr) simultaneously. Data on energy balances as reported by Close (1970) and Verstegen (1971) were used to test the formula. These data were obtained in experiments on 54 animals at various temperatures and housed in groups of 3 to 5. In the formula heat producton is described as a function of intake of metabolizable energy (ME), metabolic weight (WP) and ambient temperature (T):

$$H = \left( {1 - a} \right) * ME + a * {k_m} * {W^p} + \ln \left( {l + {e^{\left( { - c * \left( {Tcr - T} \right) * {W^p}} \right)}}} \right)$$

Results show that the residual error with this model is lower as compared to the error with linear functions used so far.