A practical method for induced moulting of caged layers that combines full access to feed and water, dietary thyroactive protein, and short day length

Abstract

This paper reviews and presents data suggesting that the use of thyroxine (T₄) to induce moult in poultry may be a viable alternative to previous methods involving feed withdrawal or feed avoidance. Studies completed in wild and domestic avian species have indicated that T₄ is associated with the natural moulting process. Four experiments, spanning the range from using a purified, injectable form of T₄ to a cost effective commercially available product, iodinated casein (economical source of T₄) that can be fed to hens via a standard poultry ration, are presented. Since hens have full access to the diet during the induced moult, it is hoped that the procedure will be acceptable both to the poultry industry and to organizations concerned about the welfare of birds during this period of their annual cycle.

Keywords::

• hens
• thyroxine
• iodinated casein
• photoperiod
• moulting procedure