Egg shell quality of laying hens fed on different levels of deffated rice bran and of phytase

Abstract

A total of 864 laying hens H&N Nick chick, of 90% initial egg production, were used in nine treatments with eight replications, in a completely randomized design, with a factorial arrangement 3 × 3 of treatments: 0, 20 or 40 % of deffated rice bran (DRB) and 0, 300 or 600 phytase units (PTU)/kg. Data were analysed by analysis of variance, followed by polynomial regression. As DRB increased there was a decrease of egg specific gravity, and egg shell calcium deposition and weight. Addition of phytase corrected the adverse effects on egg shell quality as dietary DRB increased.