Moulting in poultry

Moulting in chickens and other poultry is the natural process of shedding and renewing feathers.

Moulting is triggered by:

• hormones secreted by the thyroid gland
• completion of the laying cycle (birds lay eggs for a certain period of time)
• reduction of day length, resulting in reduced feeding time and consequent loss of body weight.

Other external factors can also bring on feather loss. Induced or forced moulting is not considered industry practice.

Laying hens

Adult birds will normally moult once a year. This usually occurs in autumn when daylight hours are getting shorter but may vary depending on the time of year the bird started laying.

The first adult moult will usually occur at 16–17 months, depending on the time of year the hen started laying. During the moult, egg production ceases while the bird builds up its nutrient reserves. This is the most important moult for producers.

Moulting often ends by July and the hen will start to lay again.

Pullets

Before pullet hens (young hens less than 1 year old) start to lay eggs, they will go through 1 complete moult as a chick and then 3 partial ones.

Pullets that start laying in early spring (August) should lay well into April (9 months) but, unless artificial lighting is provided, most will moult during May and June.

Egg production

The time a laying hen ceases production and goes into moult is usually a reliable indication of whether or not she is a good egg producer.

Poor layers:

• moult early (November–December)
• are out of production for 6 to 7 months
• replace their feathers in 6 to 8 weeks
• seldom cast more than a few feathers at a time and rarely show bare patches.

High egg producing hens:

• moult late and for a short period of time (no more than 12 weeks)
• replace their feathers in 2 to 4 weeks
• come back into production very quickly.

It is common to see a late and rapid moulting hen practically devoid of feathers, showing many bare patches over its body.

Hens in their second year of egg production (after the first adult moult) will produce 10 to 30% less than in their first year of laying. Their laying rate is lower and they do not lay early in the following autumn.

Hens in their third year of egg production (after the second adult moult) produce:

• only 70 to 80% of the eggs they produced in their second year
• approximately 60% of the number produced in their first year.

Cockerels

Cockerels (male chickens or roosters) also moult. While undergoing a moult they are nearly always infertile because they lose weight and their reproductive physiology is in a resting phase.

Take care to ensure cockerels do not lose more than 25% of their body weight while moulting as this can lead to sterility.