The Influence of Dietary Phosphorus Level on Plasma Calcium and Phosphorus, Eggshell Calcium and Phosphorus

Abstract

This study was conducted to determine the effect of dietary nonphytate phosphorus level and vitamin-D₃ on serum and eggshell calcium and phosphorus concentrations of laying hens in late production period. One hundred ninety two 70 weeks white Lohman LSL laying hens were randomly assigned to eighty groups equally (n = 24) each treatment was replicates six times. Experimental diets were prepared by adding non phytate phosphorus at the levels of 0, 0.15, 0.30 and 0.45% to basal diet with and without vitamin D₃ (3000 IU/kg) respectively. Study was lasted for 8 weeks. All diets were isocaloric and isonitrogenous. Serum calcium and phosphorus, eggshell calcium and phosphorus concentrations were evaluated in this study. All parameters were measured the serum Ca and P, eggshell Ca and P levels were influenced from dietary treatments by statistically significant (P < 0.01). NPP supplementation decreased serum Ca levels, incontrast, increased eggshell Ca levels linearly as increasing dietary NPP levels. NPP supplementation also increased both serum and eggshell P levels, when vitamin D₃ was omitted from diet. On the other hand, vitamin D₃ supplementation caused some significant changes on Ca and P levels in serum and eggshell content. Vitamin D₃ supplementation increased both serum Ca and eggshell Ca, but, decreased serum P level. On the other hand, vitamin D₃ supplementation significantly increased eggshell P in first two groups but decreased the eggshell P in following groups. Serum phosphorus was directly related to dietary phosphorus levels whereas, serum calcium was inversely related to dietary phosphorus levels.