Food choice and intake in chickens.

Abstract

The choices birds make when confronted with more than one food have been studied in a variety of contexts. This chapter focuses on the domestic fowl (both growing broilers and laying hens) as its example species, as this is where much of the relevant research has been carried out. The chapter considers the factors that affect food choice and the controls exerted by sensory and nutritional factors in the context of learned preferences and aversions. This is linked to the control of intake of a single food, which is also subject to learning. Many studies on food choice have been carried out without proper consideration of the nutritional context, which pertains to the metabolic consequences of eating a particular food. In order to make a proper study of birds' ability to choose between foods for the optimum nutritional benefit, it is necessary to know not only the composition of the foods on offer but also the weight eaten. Observations in the wild do not usually give sufficient information for proper interpretation of observations to be made and the focus of this chapter will be on experiments carried out under controlled conditions in which appropriate measurements can be made.