Mature chickens normally undergo one complete moult a year, usually in autumn. However, this can depend on the time of the year the bird started laying.
Natural moulting usually begins sometime during March or April, and should be finished by July, when egg production recommences.
The three main factors that bring about moulting are:
- physical exhaustion and fatigue
- completion of the laying cycle (usually 11 months)
- reduction of the day length, resulting in reduced feeding time and consequent loss of body weight
Natural moults can occur any time of year if chickens are subjected to stress. Common stress factors that can induce moulting include disease, temperature extremes, poor nutrition, predators and poor management.