Effects of Hen Age and Force Molting Programs on Some Egg Quality Traits in Laying Hens

Abstract

The aim of this study was to determine the effects of hen age and force molting programs on egg quality during postmolt period. The experiment was conducted using 320 Hy-Line W36 hens (63 and 75 week of age) randomly assigned to experimental groups (five replicates of 8 hens for each treatment). The experimental design of the study was a 2 × 4 factorial arrangement of a completely randomized design.  Eight treatments were compared in a 2 x 4 factorial arrangement with 2 age treatment (63 and 75 week of age) and 4 force molting treatments [feed withdrawal (FW), 100% alfalfa (A), 50% alfalfa and 50%oat (AO), and 100% oat (O)]). The respective diet and water were allowed ad libitum, and hens were placed on an artificial lighting program of 8L:16D during the 10 d molt period. At 11 d, all hens were fed a layer diet and the lighting program was changed to 16L:8D. Three eggs from each replicate were analyzed for egg quality traits on every 2 week from week 3 to 36 during the postmolt period. The hen age had no significant effect on egg quality traits in postmolt period. Molting methods had significantly (P<0.05) effect only on egg weight during postmolt period. The O group had significantly (P<0.05) higher egg weight than FW group. However, there were no significant differences among molting treatments for shape index, specific gravity, shell strength, albumen height and Haugh Unit during postmolt period. Our results indicated that hen age did not influence the egg quality during the postmolt period. In addition, as non feed withdrawal methods, especially O program can be used successfully for force molting.