Dietary calcium concentration does not affect endogenous phosphorus loss in broiler chickens fed purified diets during a 3-day experimental period

A study was conducted to evaluate the impact of increasing levels of dietary calcium in phosphorus-free diets on the determination of basal endogenous loss (BEL) of P in broiler chickens. Male Cobb 500 broilers were fed a corn–soybean meal diet that met their requirements until day 19 post hatching, when they were allotted to three dietary treatments (8 replicates each with 10 birds/replicate) consisting of purified P-free diets with 0, 4, or 8 g/kg of calcium in a randomized complete block design using body weight as blocking factor. Data were analyzed in a two-way ANOVA. The diets were fed for 3 days, and excreta and ileal digesta samples were taken at the end of the trial. Calcium concentration in the excreta and terminal ileum linearly increased ( P < 0.001) as dietary calcium increased. The BEL of P were 205, 230, and 236 mg/kg dry matter intake (DMI) in the diets containing 0, 4, and 8 g/kg calcium ( P = 0.400), respectively. Additionally, the BEL of calcium was determined to be 99 mg/kg DMI using the calcium and P-free diet. In conclusion, increasing dietary calcium from 0 to 8 g/kg in P-free diets did not affect the BELs of phosphorus.