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The practice of forced moulting involves inducing hens to shed their feathers unnaturally quickly by shocking their system. This ‘shock’ can be achieved by withdrawing feed for 10-14 days and reducing lighting.
After one year of production, hens will naturally stop laying whilst undergoing an annual moult. Forced moulting is carried out to make hens return to lay in as short a time as possible.
Forced moulting is widely practised in countries such as the USA and Japan.
Forced moulting results in a huge increase in stress and suffering to the hens, and a dramatic increase in mortality.
UK legislation has resulted in the abolition of the most severe aspects of forced moulting, namely any total withdrawal of food, water and lighting.
There are 30 million laying hens in the UK, 270 million in the USA

Moult: The periodic shedding of hair or fur in mammals, or of feathers in birds.” Concise Oxford Veterinary Dictionary

Forced moulting is carried out at the end of the annual laying cycle and, in its severest form, involves depriving hens of food for 10-14 days and reducing day length. This shocks their bodies into moulting, replacing their feathers and returning birds to lay much more quickly than under natural conditions. Forced moulting therefore shortens the period of non-production in those flocks where a second year of lay is required (in Europe, most hens are slaughtered after their first year of lay). It also results in high mortality and “a huge increase in stress and suffering”1.

Bone Weakness

Bone weakness in laying hens is a major cause of concern. Although it is mainly attributable to the battery hen’s almost total lack of exercise2, the great demand for calcium for the formation of egg shells depletes natural stores of calcium in the hen’s body, often leading to severe osteopenia3. Under commercial conditions, farmers who keep the same flocks beyond one year are eager to hurry the moulting process along, in order to minimise the unprofitable period of non-production. It is likely that hens force moulted for a second or even third year of lay suffer from a greater incidence of brittle bones.

Malignant Tumours

Another welfare problem associated with pushing hens to lay more eggs is the development of malignant tumours of the oviduct, likely to be exacerbated by force moulting for a second term of production.

Under natural conditions, wild hens and other birds lay eggs with the sole purpose of hatching their young - sitting on a clutch of a few (mainly fertilized) eggs once or twice yearly, when day length is increasing. Now the modern hybrid layer can produce up to 300 eggs in her first year of lay, but not without cost to her health.

In one investigation, a significant proportion of malignant tumours of the oviduct was identified in 20,000 ‘spent’ layers selected from ten different farms. The researchers concluded, “...the increase in the prevalence of the (magnum) tumour coincides with continued selection of fowl for high egg production.”4 A second year of lay is likely to exacerbate the problem.

The Legal Situation

THE WELFARE OF FARMED ANIMALS (ENGLAND) REGULATIONS 2000 (Statutory Instrument 2000 No. 1870)

In the UK, inducing moult by feed withdrawal is illegal. Under schedule 2, which is specific to battery hens, para 5 states: “Except where therapeutic or prophylactic treatment demands otherwise, all laying hens shall have access to adequate, nutritious and hygienic feed each day in sufficient quantity to maintain them in good health and to satisfy their nutritional needs, and to adequate fresh drinking water at all times.” Induced moulting would not qualify as therapeutic or prophylactic treatment.

Furthermore, in Schedule 1, under the section entitled “Feed, water and other substances”, para. 22 states: “Animals shall be fed a wholesome diet which is appropriate to their age and species and which is fed to them in sufficient quantity to maintain them in good health, satisfy their nutritional needs and to promote a positive state of well-being.” Para 25 states: “All animals shall either have access to a suitable water supply and be provided with an adequate supply of fresh drinking water each day or be able to satisfy their fluid intake needs by other means.”

Government Guidelines - Codes of Practice

There are Codes of Practice for all UK farm animals, drawn up following consultation with the independent Farm Animal Welfare Council and “a very wide range of organisations interested in the care of farm livestock”5, issued with the approval of Parliament. These codes are not mandatory, but are intended to give guidance. Nevertheless: “...in the event that a livestock keeper is prosecuted for causing unnecessary pain or unnecessary distress, a breach of the code can be brought forward in evidence and may be regarded by the court as tending to establish guilt.”

Paragraph 39 of the Codes of Recommendations for the Welfare of Livestock - Domestic Fowls, reinforces the legal requirement: “In no circumstances should birds be induced to moult by withholding feed and water.”

NB: Some years ago, Chickens’ Lib urged ADAS (the then MAFF-funded Agricultural Development and Advisory Service) to change the advice in its booklet on forced moulting, which suggested that farmers turn off the lights for 24 hours, to start the forced moult period. This advice condoned illegal practice, since daily inspection, with adequate lighting, was (and still is) a legal requirement.

Forced Moulting in the UK?

Some defend forced moulting by arguing that the birds can be fed a “filling” diet, but one which will nevertheless induce a rapid moult. In the barren battery cage, the same type of feed (a fine textured meal with precise amounts of nutrients, etc) is fed, day after day. During the forced moult, plain barley or oats may be supplied instead. The shock to the birds’ system of this sudden change can achieve the desired result of a more rapidly induced moult. The additional suffering of these deprived birds being force-moulted (legally) in this way in the UK might be hard to prove in a court of law.

Forced moulting is carried out in the UK, though not on a wide scale. No figures are kept for the percentage of moulted birds, but the general impression is that the practice is less common now than it was a few years ago. Most laying hens are slaughtered when around 76 weeks of age (i.e. after one year in lay). The reason for forcing a moult is to keep the birds for a further year of lay: eggs from older hens are larger, a feature favoured by some consumers, and using the same birds for a further year saves on buying new stock.

Probably the main reason for the decrease in the popularity of forced moulting springs from the fact that some supermarkets put an age limit on laying hens supplying them. This is because shell and egg quality deteriorate markedly when the birds reach around 60 weeks into lay. In FAWN’s experience, this deterioration applies far more to factory-farmed hens’ eggs than to eggs produced under humane, extensive conditions.


Duncan, I.J.H., undated. Animal Welfare Issues in the Poultry Industry. University of Guelph, Ontario.

, D.M., Dept. of Clinical Veterinary Medicine, University of Cambridge. The Needs of Laying Hens and Some Indicators of Poor Welfare. Paper presented at the Seminar organised by The European Conference Group on the Protection of Farm Animals, (Brussels, 1992).

Page 6 in Report on conference sponsored by the RSPCA, Osteopenia in Laying Hens. April 1989.

Anjum, A.D. et al, (1989). Oviduct Magnum Tumours in the Domestic Fowl and Their Association With Laying. Veterinary Record, Volume 125, Number 2, 42-43.

Notes from Ministry of Agriculture, Fisheries and Food accompanying new welfare codes of recommendations for sheep, but applicable to all MAFF farm animal Codes of Recommendations.


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