INDUCED MOLTING PROCEDURES IN LAYING FOWL

Several successful methods of inducing moulting have been used to recy cle laying hens, the majority of which require an optimum weight loss of 25-30% to achieve maximum egg production during the post-moulting p eriod. The conventional feed restriction procedure is most often used in the egg industry because it is a simple, practical and economical t echnique that can be used in combination with light and/or water restr iction. Mineral-induced moulting procedures, such as the use of high l evels of either aluminium in the form of a soluble salt or dietary zin c, have also been used successfully. In addition, low levels of dietar y zinc combined with a low calcium diet have also induced moulting in laying hens. The use of low sodium diets has been equally as successfu l as the conventional feed restriction technique as a means of inducin g a moult. Although mineral-induced moulting procedures produce simila r results to the conventional feed restriction techniques in post-moul ting egg production, but with lower mortality rates, some of these pro cedures may not yet be practical for use in the egg industry. Hormone- induced moulting is another method and involves the use of the gonadot ropin-releasing hormone (Gn-RH) agonist. It has an advantage over the conventional feed restriction procedure in that it does not require se vere initial body weight loss to attain maximum egg production in the post-moulting period.