Selfselection of dietary protein and energy by broilers grown under a tropical climate : Effect of feed particle size on the feed choice. Poultry Sci

ABSTRACT Three hundred broiler chicks (Hubbard) of both sexes were assigned to five feeding treatments: T0 received a complete diet (control), T1 was a choice feeding system with simultaneous access to an energy-rich feed (ground corn) and a protein concentrate (43.7% CP), and T2, T3, and T4 were introduced to choice feeding after 1, 3, and 5 wk, respectively, of consuming the complete diet. At 1-d-old, T1 chicks showed a marked preference for corn, with only 21.4 % of their intake being the protein concentrate diet. Intake of the concentrate progressively increased to 40 to 45 % after 3 d of adaptation, resulting in diets with 22.5 to 24.3 % CP. When broilers fed the complete diet for 1 to 5 wk (T2, T3, T4) were changed to choice feeding, on the 1st d, their feed choice intake was similar to that of T1 chicks at the same age. Visual observation and tactile assess-ment of the feed particles during the initial period allowed the chicks to quickly evaluate the new feeds and to adapt their feeding behavior. Although total feed intake to 6 wk of age was not significantly affected by the feeding treatments, broilers on choice feeding selected diets with a lower percentage of CP and had lower live body weights at 6 wk than those fed the complete diet (T0)