Feather Removal from Spent Hens up to 24 Hr Post-Mortem

Abstract

Rendering spent hens is an option for egg producers who find it difficult to sell aging flocks to traditional markets. Renderers, however, may have problems with feathers on hen carcasses which can make the product difficult to handle and adulterate it with indigestible material. Whole-bird hydrolyzation would improve the digestibility of the feather proteins but degrade the quality of the meat proteins. These problems could be eliminated if feathers were removed from the carcasses before rendering. Our experiments indicated that feed withdrawal for up to 3 days before hens are killed has little influence on ease of feather removal and that spent hens dead for up to 24 hr can be picked adequately for rendering. The feathers remaining on picked hen carcasses constituted only 0.1-0.2% of the total picked body mass. This feather-picking efficiency would allow Renderers to accept spent hens virtually without limitation, making it feasible, perhaps, to install simple batch scalding and picking facilities at rendering plants to receive hen carcasses. Picking spent hens that have been dead for at least several hours requires attention to scalding bath temperature, scalding time, and carcass temperature because the primary and secondary feathers of the wings release under different conditions than feathers on other body areas, and carcasses of different temperature require different scalding conditions for an optimum pick.