Non-phytate phosphorus requirements of egg laying pullets from 0-3 weeks of age and carryover effects of phosphorus deficiency at 6, 9, 12 and 18 weeks of age

The objectives were to determine the non-phytate phosphorus (nPP) requirement in 0 3-wk-old laying hen pullets using body weight (BW), mortality corrected feed conversion ratio (FCRm), tibia ash expressed as (TAW) and percentage (TAP), total bone mineral content (BMC) understand longer term effects of early deficiency on over time. Hy-Line W36 distributed across 42 cages resulting 7 dietary treatments (0.15, 0.22, 0.29, 0.36, 0.43, 0.49, 0.53% nPP 1.0% Calcium) fed 6 replicate 30 chicks. After 3 wk, all birds switched common corn-soybean meal diets that contained 0.48, 0.45, 0.48% 1.0, 2.5% Ca from 3–6, 6-12, 12–15, 15–18, respectively. Pullets euthanized at 3, 6, 9, 12, 18 wk age for BMC determination. Linear quadratic broken-lines used estimate requirements pullets. was 0.31% BW; 0.27% FCRm; TAP; TAW; 0.32% linear broken line analysis. Low concentrations period reduced BW (P ≤ 0.05), but after 9 no response criteria different among > 0.05). These data indicate is between 0.27 dependent used, there are few long-term low feeding when provided an adequate diet