The Influence of Force Molting on the Incidence of Uncollectable Eggs

Two experiments were conducted to determine the influence of force molting on egg shell quality. Approximately 15,000 Honegger and 15,000 Babcock hens, 17 months of age, were force molted using conventional methods. Just prior to force molting, the incidence of shell-less, ultra-thin shell and thin-shell eggs (uncollectable) was determined. Sheets of metal were hung at random beneath the cages of 800 birds in each population to catch all eggs that dropped through the cages. Fifty hard-shell eggs were collected at 2-hr. intervals from 6:00 a.m. to 6:00 p.m. and specific gravity and egg weight were determined. The above procedure was repeated at 8, 13 and 24 weeks after the molt. The hens in both experiments were laying an average of 12.6% uncollectable eggs prior to molt. The incidence was reduced to 2.9%, 1.4% and 8.1% for the 8, 13 and 24-week post-molt period, respectively. Egg weight significantly increased at the 8-week (experiments 1 and 2) and 24-week (experiment 1) test periods. Egg specific gravity was increased only by the 13-week test period in experiments 1 and 2. Time of oviposition had no influence on the degree of increase in specific gravity or weight of eggs caused by force molting. It was concluded that the incidence of uncollectable eggs can be significantly reduced at least 3 months by force molting.