The productive performance of brown egg-laying hens induced to molt at different ages

Objective. The application of the ovarian rest technique on brown egg layer birds was evaluated in this investigation as well as the effect of age and feed duration withdrawal have over their productive behavior. Materials and method. 840 Hy Line Brown hens at 64 weeks of age, evaluating three ages (65, 70 and 75 weeks) and three feed withdrawal periods (5, 10 and 15 days) in a completely randomized, nested, fixed and balanced effects model was used. The calcium consumption during feed withdrawal (g/bird/day), percentage of production, egg weight (g), conversion per egg mass and eggs per housed hen were evaluated. Results. The age factor presented a significant effect (p<0.05) for food consumption, day of the first egg laid post-molting, days without production, day of return to 50% of the production post-molting, egg weight, number of eggs average, egg mass, conversion and (p<0.01) production percentage. After comparing the control treatments, the 75-5 treatment presented a significant effect (p<0.05) for food consumption, average number of eggs, egg mass and conversion. Conclusions. Birds with a greater feed withdrawal period presented a greater unproductive post-molting period, greater weight loss and greater consumption of food which reflects on high conversion and could be defined as productive inefficiency. The comparison between lines showed that cease of production.