Estimation of endogenous calcium and phosphorus loss in layer parent cockerels

A study was carried out to estimate the endogenous loss of calcium (Ca) and phosphorus (P) in white leghorn parent cockerels. P is one of the most important elements both in feeding and as well as environmental point of view. It is considered as one of the most polluting nutrients in areas of intensive rearing of animals because they excrete high levels of P in their faeces. Ca and P serve a variety of functions including structure and strength of bones and cell walls, buffering systems and also energy transfer mechanisms. While calculating the factorial requirement of Ca and P for layers, the knowledge on the maintenance requirement and as well as amount of minerals excreted through the eggs. For this, thirty parent cockerels were divided into three replicates each consisting of ten birds. The birds were starved and their faeces are collected and analysed for Ca and P contents. The endogenous faecal excretion of Ca and P was found to be about 245.24±6.94 and 101.95±1.21 mg/kg of metabolic body weight, respectively.