Efficacy of phase-feeding in supporting growth performance of broiler chicks during the starter and finisher phases.

A feeding regimen has been developed that uses regression equations to predict amino acid requirements over time. Phase-feeding (PF) of broilers was tested to evaluate its efficacy compared with feeding broilers NRC or Illinois ideal chick protein (IICP) recommendations. In Experiment 1, NRC or IICP requirements for lysine, sulfur amino acids, and threonine were fed from 0 to 21 d, whereas PF was tested using a series of three diets (0 to 7, 7 to 14, and 14 to 21 d). No differences (P > 0.05) in weight gain, feed intake, feed efficiency, digestible amino acid intake, or gain per unit digestible amino acid intake were noted among chicks fed NRC, IICP, or PF diets. In Experiment 2, NRC or IICP requirements were fed from 40 to 61 d, whereas PF was tested using a series of three diets (40 to 47, 47 to 54, and 54 to 61 d). No differences (P > 0.05) in weight gain or feed intake were observed, but the feed efficiency of birds fed the IICP diet was decreased (P < 0.05). The IICP and PF diets resulted in decreased (P < 0.05) digestible lysine and threonine intake; gain per unit digestible lysine and threonine intake was increased (P < 0.05) by PF. No differences (P < 0.05) in breast meat, wing, or leg yield were noted among treatments. Economic analysis indicated that PF may facilitate reduced dietary costs without sacrificing growth performance or carcass yield.