Moulting and the laying hen
Mature birds normally undergo one complete moult 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.
Moulting often ends by July and the hen will start to lay again. The main factors that trigger moulting are:
- hormones secreted by the thyroid gland
- physical exhaustion and fatigue
- 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.
Induced or forced moulting is no longer considered industry practice in Queensland. In emergency or unforeseen situations, such as a disease outbreak, it may be considered an option.
Pullets and laying
Pullets hatched in season (i.e. spring) should produce eggs continuously for 11 months. For example:
- Pullets that start laying in June (at 6 months of age) should continue to lay until the following April.
- Pullets that start laying in March should continue to lay until the following February. Occasionally some of these birds may moult after laying for only a few weeks, but should begin laying again after the shortest day of the year (22 June), and continue until the following autumn.
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.
Hens and laying
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.
- moult early (November–December)
- are out of production for 6–7 months
- replace their feathers in 6–8 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 2–4 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.
Birds in their second year of egg production (after the first adult moult) will produce 10–30% less than in their first year of laying. Their laying rate is lower and they do not lay early in the following autumn.
Birds in their third year of egg production (after the second adult moult) produce:
- only 70–80% of the eggs they produced in their second year
- approximately 60% of the number produced in their first year.
Year-round egg production
You can achieve year-round egg production by purchasing pullets in autumn at point-of-lay (5–7 months). This provides sufficient eggs while the older birds are moulting. As the rate of laying by pullets declines in summer, the additional eggs from the older moulted birds should sustain an adequate supply.
The following autumn, allow the best pullets to moult, cull older birds and purchase more point-of-lay pullets (20% pullet wastage occurs because of deaths and culling). You only need to buy 70% of pullets to give a relatively constant year-round supply of eggs.
Keeping hens during the moult
- It may be cheaper to keep a bird through a moult than to buy replacement pullets.
- Fewer replacement pullets are needed and buying can often be deferred.
- Only high-producing, efficient birds remain if strict culling occurs during the first year.
- Hens in their second and third years of laying produce fewer eggs.
- Conversion of feed into eggs and feed cost per dozen eggs is higher.