Supplemental Magnesium in Diets for Growing Pullets and Hens: Growth, Skeletal Development, and Egg Production

Abstract

SUMMARY: Growing pullets and subsequently laying hens were fed practical type corn-soybean meal diets with and without 0.1% supplemental magnesium oxide (MgO) through 36 wk of age. During the pullet phase, one half the chicks were allowed access to perches beginning at a day of age (2.5 cm) and perch height was increased in 2.5 cm weekly increments through 3 wk. Access to perches had no effect on body weight or skeletal development, and there were no significant perch x MgO interactions. There was a significant increase in cortical bone density between 6 and 12 wk of age and an increase in cortical density in pullets fed supplemental MgO (P < 0.065). Pullets fed supplemental magnesium had increased body weight at 18 wk (P < 0.039) and 21 wk (P ≤ 0.077) of age. There were no subsequent effects on hen-day egg production or egg weight except during the fourth period when hens fed supplemental MgO had increased egg size (P ≤ 0.071). In conclusion, supplemental MgO had a positive effect on selected aspects of pullet skeletal development during the early phases of growth and body weight near photostimulation and the onset of egg production.

Keywords

• magnesium
• pullets
• egg production
• skeletal development
• perches