It is known that poultry, as well as other animals, adjust their voluntary
intake of feed to maintain appropriate daily intake when offered diets
with different energy and protein densities. Under natural or
experimental conditions, chickens eat different feedstuffs that are
individually incomplete, so that the challenge consists in evaluating all
the available feedstuffs and selecting an adequate diet from them.
The cafeteria method, or free-choice feeding, allows the animal to
formulate its own diet, selecting the feeds based on the requirements
for maintenance and production, which may increase efficiency when
compared to complete diets. Producers with little experience adapt well
to this system, which is labor-saving and offers good results in breeding
programs for high production (Oliveira, 1999).
It is necessary to know which factors might influence the selection
of the diet by the bird under a free-choice situation. Emmans (1978)