Egg production, tissue deposition and mineral metabolism in two strains of commercial layers with various levels of manganese in diets

Abstract

An experiment was conducted to study the effects of dietary manganese levels on performance and metabolism of minerals in two strains of commercial layers. A maize and soya-bean meal basal diet containing 25 mg kg −1 of manganese was supplemented with 0, 20, 40 and 80 mg kg −1 of the element from reagent grade manganese oxide. No significant difference in egg production, egg weight or feed conversion was observed when the supplement of manganese in the diet increased from 0 to 80 mg kg −1, but the shell thickness for two strains improved significantly. No interaction in mineral deposition was observed between the two strains. Tibia and liver manganese concentrations were increased linearly with increasing level of the element in the diet and retention of manganese was increased from 20.2 to 62.8% for Hy-line and from 15.2 to 63.2% for Lohman strain. Thus, the manganese requirement of laying hens appears to be at least 105 mg kg −1 (25 from basal diet + 80 ppm of supplement).