Midnight Feeding of Commercial Laying Hens Can Improve Eggshell Quality

Abstract

Three field experiments were conducted to determine the influence of midnight feeding of commercial egg layers on eggshell quality. Experiment 1 consisted of four houses containing 90,000 hens each, which received feed at midnight. Four other houses served as controls. Specific gravity increased on the eggs collected at 09:00 hr from hens fed at midnight. Shell weight also increased in three of the four comparisons as did specific gravity of eggs collected at 15:00 hr. Shell weight decreased in three of the four comparisons when the hens were given the midnight feeding and eggs were collected at 15:00 hr. In Experiment 2, eggshell quality was measured before initiating the midnight feeding program in two cool-cell-pad houses (containing 71,000 hens each). There was an improvement in shell weight, percent shell, and shell weight per unit surface area (SWUSA) in the cool end of both houses. However, shell weight was not affected in the warm end of the houses. In Experiment 3, comparisons were made in two pairs of houses. Eggshell quality was measured on day 1 and after four days of midnight feeding. Shell weight was increased with both comparisons. However, percent shell and SWUSA were not affected.