Diet energy and feed intake in chickens

Abstract

Energy homeostasis is of fundamental importance to animal well-being as well as in the feeding of species like chickens. Optimizing the balance between energy intake and expenditures is required for efficient, highly productive flocks, and understanding its relationship to production characteristics including energy and feed intake is fundamental to the formulation of chicken diets and levels of other dietary nutrients. A historical perspective on this relationship is that chickens alter feed intake to maintain energy intake when diets contain variable dietary energy. In turn levels of other nutrients, and in particular amino acids, should be adjusted in accordance. However, control of feed intake is complex and even if this perspective were correct, multiple factors can compromise the appropriate adjustment in feed intake. The validity of broilers altering feed intake in response to dietary energy has been questioned for some time and more recent evidence suggests that modern strains of laying hens also are unable to accurately or reliably alter feed intake in response to dietary energy levels. Based on the premise that chickens do not appropriately respond to dietary energy, diets must therefore be formulated to ensure adequate dietary energy to meet the bird’s requirements for maintenance and production, and thereby maximize the protein accretion potential of the diet.