Dietary L-Thyroxine to Induce Molt Without Feed Withdrawal in Laying Chicken, Broiler Breeder, and Turkey Breeder Hens to Extend Production

Molting (reproductive rejuvenation) of poultry to extend table or fertile egg production is a well accepted commercial practice in the U.S. However, the conventional method of ~10-day feed withdrawal to induce molt is increasingly viewed as unacceptable by McDonald's, Wendy's, AVMA, and the egg consuming public. The use of dietary L-thyroxine (T4; the natural molting hormone) for poultry can provide an effective commercial method of inducing molting while providing full access to treated feed and water. These studies will gather further information on the feasibility of the concept and how it should be carried out in chickens and turkeys to extend egg production, improve profitability, and assure animal welfare.