Dislocated calcium alimentation for broilers

The University of Sydney

  • Project code: PRJ-006015

  • Project stage: Closed

  • Project start date: Friday, July 1, 2011

  • Project completion date: Thursday, August 1, 2013

  • National Priority: CME-Priority 3-Contributing to efficient and secure chicken production systems


Calcium is an essential nutrient for poultry, being involved in various digestive processes and of course of pivotal importance in bone development. It is generally recognized that broiler diets should contain 0.9-1.1% total Ca in order to satisfy the animals requirement and that this be coupled to digestible P in a ratio of 2:1. However, though Ca is an essential nutrient its presence in broiler diets results in a drastic reduction in the digestibility of phytate-P and also impairs the value of microbial phytase (Selle et al., 2009). One obvious way to satisfy the animals Ca appetite but to minimize the adverse effects of Ca is to dislocate the provision of Ca from the diet and to offer instead a supplementary Ca source. Thus, this project will explore the usefulness of a novel Ca delivery strategy whereby supplemental Ca is removed from the diet and offered instead as grit for concomitant consumption. The effect of this strategy, as compared with conventional feeding, on Ca intake, leg health, FCR and the opportunity for feed cost reduction will be explored.


Chicken Meat

Research Organisation

The University of Sydney

Objective Summary

It is the purpose of this project to explore a novel Ca provision strategy where supplemental Ca will be removed from the diet and offered instead as a ‘choice-feeding’ grit. Wood-Gush & Kare (1966) identified that poultry have a specific appetite for Ca and ‘dislocated’ Ca alimentation has been attempted successfully in broilers previously (Joshua & Mueller, 1979) though not in the context of phytase and phytate interactions. Thus, this project will assess the usefulness of choice-feeding Ca in broiler production in conjunction with microbial phytase. Various aspects must be explored including equilibrating Ca intake, assessing leg health, FCR, optimum phytase dosing, Ca:P ratios, formulation of the Ca-deficient diet, the Ca concentration of the supplemental source, litter moisture, economics, environmental impact, feeding behaviour and optimum positioning of the Ca source in the context of the rest of the diet. The ultimate objective is to establish whether the dislocation of Ca from the rest of the diet offers economic advantages for broiler production. This may be achieved by radical feed cost control in the basal (Ca deficient) diet via ‘space saving’, improved P and AA digestibility and also via improved performance and leg health.