Challenges of accurately defining the nutrient requirements of heat-stressed poultry

Faculty of Veterinary Science, University of Sydney, Camden, New South Wales, Australia 2570. derick.balnave@bigpond.com

The number of factors that influence the nutrient requirements of heat-stressed poultry, through alterations in metabolism and biological responses, are much greater than those that influence the nutrient requirements of poultry at thermoneutral temperatures. Therefore, multiple dietary nutrient specifications adjusted for different intensities of heat stress experienced in different geographical locations, and for different management options used to combat such conditions, are likely to be required by poultry nutritionists. Financial constraints on the construction of suitable research facilities have limited the accumulation of knowledge concerning dietary nutrient specifications for heat-stressed poultry. Thus, input from commercial enterprises has contributed significantly to the accumulation of existing knowledge. Knowledge of the energy and amino acid requirements of birds during heat stress are best known, whereas vitamins and trace minerals remain among the least-researched groups of nutrients.