Effect of dietary calcium and zinc levels on the performance of layers

An experiment was conducted on naked neck x White Leghorn (102) layers of 31 weeks age to determine optimum levels of Ca and Zn for egg production and egg quality traits. Six dietary treatments with two levels of calcium (2.5 and 3.0%) and three levels of zinc (30, 50 and 80 mg/kg) at each calcium level were formulated in a 2x3 factorial design. The hen day egg production, egg weight, feed intake, feed conversion ratio and body weight change did not differ (P>0.05) due to either main effects of calcium and zinc levels or their interaction in the diet. The level of calcium affected the albumin index (P<0.05), shell thickness (P<0.01) and shell weight (P<0.01). The shell thickness-and shell weight were higher (P<0.01) in 3.0% calcium diet than 2.5% calcium diet. Zinc level did not influence different egg quality parameters. The calcium x zinc interaction was significant for albumin index (P<0.01) only. The results indicated that a dietary level of 3% calcium and 30 mg Zn/kg feed was optimum for egg production and egg quality traits in naked neck x WL layers.