Carlos M. Becerril Pérez

Niveles de fósforo disponible aparente en pollas Leghorn blanca durante las etapas de iniciación, crecimiento, desarrollo e inicio de postura

Phosphorus (P) is important for the growth and metabolism of pullets and young laying hens, although the requeriments of this mineral could be overvalued. An experiment was conducted with 750 Hy-line W-36 pullets to evaluate the effects of apparent available phosphorus (aaP) levels during starter (1 d to 6 wk), growing (7 to 12 wk), development (13 to 18 wk), and initial laying period. The analyzed variables were: body weight (BW), feed intake (FI), percentage of P in excreta (PPE) and tibia bone (TBP), tibia breaking strength (TBS), egg mass (EM), and specific gravity (SG). The evaluated aaP levels had no effect (P>0.05) on FI, FP, TBP, RB, or EM in the stages under study. There was a difference (P 0.05) in the starter period, the optimum biological levels for growing and finishing stages were 0.28 and 0.26 % of aaP, respectively. It was concluded that the requirements of apparent available phosphorus could be lower than the value suggested by NRC (1994) for the growth stages and the variables measured, without affecting the body condition and bone mineralization of pullets.