The use of dietary thyroxine as an alternate moulting procedure in turkey breeder hens
Induced moult in poultry is traditionally achieved by removing feed and shortening photoperiod. This causes many health and welfare concerns and is thus banned in many countries. Being vital to the poultry industry, a welfare-friendly, economically viable alternative is necessary. This research investigated using thyroxine to induce moult in spent turkey breeder hens. Forty ppm dietary thyroxine supplementation for 10 days effectively induced moult when combined with a decrease in photoperiod. To further determine the minimum effective dose and its impact on the second laying cycle, a second experiment was performed. Interestingly, a successful and humane moult followed by an acceptable return into lay was achieved by simply shortening the photoperiod and providing a low energy diet for 12 weeks pre-photostimulation. Birds given at least 10 ppm dietary thyroxine for 10 days, however, had quicker, more synchronized moults and could thus be returned into production more rapidly.