Phosphorus digestibility of copra meal for broiler chickens fed different levels of non-phytate phosphorus in the pre-experimental period

Early-life nutritional interventions in broilers may modulate subsequent digestive capacity, however, the impact of phosphorus ( P ) nutrition during the starter period on basal endogenous losses ( BEL ) of P and the P digestibility of feedstuff fed in the subsequent phase remains poorly defined. This study evaluated the influence of pre-experimental non-phytate P ( nPP ) concentrations on the BEL of P and the standardized P digestibility of a potential alternative feedstuff, copra meal ( CM ), with or without phytase supplementation. The experiment employed a 2 × 3 factorial arrangement in a split-plot design. During the pre-experimental phase (d 0 to 18 post hatching), birds were assigned to two starter diets containing either deficient (3.0 g/kg) or adequate (4.5 g/kg) nPP levels (24 replicates; 8 birds/cage). In the subsequent three days, three grower diets were administered to 8 replicates: two diets utilizing CM as the sole P source (supplemented with or without 1,000 FYT/kg of phytase) with 6 birds/cage, and one P-free diet that served to correct for BEL of P with 10 birds/cage. Statistical analysis was performed using a randomized complete block in a split-plot design with starter diets as main plots and grower diets as subplots, and the P-free diet was analyzed separately. No significant interactions were found for growth performance or digestibility data. Broilers conditioned on the deficient-nPP starter diet exhibited greater ( P < 0.05) standardized P digestibility of CM (80%) compared to the adequate-nPP starter (77%), phytase inclusion enhanced ( P < 0.05) these values to 88% and 83%, respectively. The BEL of P and Ca were estimated at 116 and 204 mg/kg of dry matter intake, respectively, and were unaffected by the starter diet nPP concentration. In conclusion, while starter nPP levels did not modulate the BEL of P or Ca, they significantly influenced P digestibility. These findings suggest that pre-experimental P nutrition should be standardized when evaluating the digestibility of feed ingredients. Furthermore, copra meal had high P digestibility that was optimized by phytase supplementation.