Understanding LAYERS
Laying hens are kept in flocks made up of only a few hens to many thousands. Because of this variation in the size of the units and the various preferences of the market, there are a number of systems for housing a flock. The various systems include:
• Extensive (free-range)
• Semi-Intensive
• Intensive
THE EXTENSIVE SYSTEM
The extensive system of poultry production (commonly known as “free-range”) is based on the practice of allowing the bird access to foraging areas outside the poultry house.
This system was widely practiced prior to the development of more productive strains of poultry and better management facilities (automated feeding and watering, better housing, environmental control) around the middle of the 20th century.
Nowadays, extensive poultry production is generally practiced by a specific range of growers, including:
• Organic farmers
• Village and community groups
• Hobbyists
Housing
In broad terms there are two basic forms of housing for extensive poultry production:
1. A house or number of houses established in a permanent position
2. A number of smaller houses fitted with skids or wheels which can be moved around (see figure 7 below).
With either of these methods, the house is used to protect the birds at night and to provide somewhere for the birds to lay their eggs. Whatever the size, the hen house should be fitted with perches to allow the birds to roost at night.
There should also be sufficient nesting boxes to allow for laying.
Preventing predators from gaining access to the birds is a major consideration with free-range systems, and there are a number of ways of addressing this problem.
One popular method is to fit the houses with a small hatch (pop-hole) which can be closed to keep the hens in at night to preclude predators and opened in the morning to allow the hens out.
Another method gaining in popularity is to construct predator proof fencing around the forage areas, and place some form of guard animal (mareema dogs and wethered alpacas are both used for this purpose) to ensure the predators don’t get near the birds.
Housing for Free-range Birds
Management
The normal system is to move young pullets into a laying house about four weeks before they are due to start laying. This is done to allow them to become used to the new house and to give them time to settle in.
The pullets should be kept in the house and not allowed to range for the first two days after the move. After this time, they can be allowed out in the day. They will find their own way back to the house at nightfall – “putting themselves to bed” so to speak.
If any of the pullets roost on top of the house or in nearby branches at nightfall, they should be caught by hand and placed in the house. Birds that roost outside will almost certainly be taken by predators so it is worth trying to break this habit as soon as you notice it.
Hens on free-range are sometimes provided with food and water outside the house, however this practice is not recommended, particularly in those areas where there is a risk of avian influenza and other diseases being carried by wild birds.
Regardless of whether the feed and water is presented inside or outside the house, it is important to ensure that adequate feed and water space is provided. As a general rule, allow 100mm (4”) of feed trough space and 50mm (2”) of water trough space per bird.
Management of the forage areas is an important consideration for free-range production systems. When any class of poultry is allowed access to natural forage in the form of grasses, herbs and other green forage, they will invariably denude the area immediately adjacent to the house.
This fact is one of the reasons that moveable houses have gained popularity, particularly in organic and Permaculture applications, where sustainability and effective use of resources are important.
By regularly moving the house, the birds are presented with new forage areas on a regular basis, whilst the previously foraged areas get the opportunity to recover and rejuvenate. This process has the added bonus of preventing the build-up of harmful organisms, particularly internal parasites.
If permanent housing is to be used, careful planning is essential if the area immediately adjacent to the house is not to become denuded, overworked and “stale”. The most effective means of achieving this goal is to divide the forage area around the house into small sections, using either fixed netting fences, or moveable electrified netting.
This allows the birds to forage over a single small area at a time, and then move on to a fresh area, allowing the previously “worked” area to recover.
It is advisable to provide the birds with adequate shade away from the house. Not only does this provide for a more suitable environment during periods of hot weather and reduce the potential for certain forms of behavioural dysfunction (e.g. feather picking and cannibalism), it also encourages the birds to move away from the house, thus reducing the forage pressure on the pasture adjacent to the house.
Egg collection
Most extensive poultry operations rely on manual labour to collect the eggs. This is normally done once or twice per day. If only once a day, collection should not commence prior to 10.00am, by which time the majority of the eggs will be laid.
All laying is generally finished by around 2.00pm. It is often necessary to wash some or all of the eggs from extensive systems due to the level of fouling with dirt, faeces and contaminants on the shells of the eggs.
Disease management
Effective prevention and management of disease is another important consideration for free-range systems, as there are a number of factors that expose birds in these systems to the risk of infection. These include:
• Faecal/oral cycle: This phrase describes the process whereby faecal material containing a potential disease causing agent is re-ingested by an animal. Due to the natural foraging behaviour of poultry, this situation occurs constantly in birds that have access to their own faeces.
• Wild birds: Unless the foraging area of free-range poultry is completely netted and bird proof, it is virtually impossible to prevent some contact with wild birds. This contact can lead to the transfer of disease, including internal and external parasites.
The risk of exposure to exotic diseases such as Avian Influenza is a significant concern for both free-range producers and the poultry industry at large.
• Internal and external parasites: As noted in the points above, a combination of the faecal/oral cycle and potential exposure to wild birds makes control of internal parasites a significant problem for free-range poultry operations.
External parasites can also be carried by wild birds, and once established on a site, can be very difficult to eradicate.
• Behavioural dysfunction: In free-range operations where modern egg laying hybrids have been used, a tendency toward certain negative or damaging behaviours has been observed.
These include feather pecking, vent pecking and cannibalism. It is generally accepted that these behaviours are a result of a number of factors, such as genetics, environment and nutrition.
• Inability to effectively control environment: Due to the relatively simple nature of most houses used in free-range egg production systems, there is little capacity to protect the birds from extremes of climate, particularly heat.
Birds have a tremendous capacity to tolerate cold conditions providing they are protected from wetness and drafts, but have few mechanisms to cope with extreme heat. Provision of adequate shade outside the house is a key welfare measure in areas prone to extreme temperatures.
• Spotty liver: This condition is the cause of loss of production and some mortality across free-range flocks. Whilst the causative agents have not been identified, it is known that the faecal/oral cycle is a factor.
• Bacterial infections of the reproductive tract: Unlike caged poultry, where the egg is deposited onto a relatively clean wire floor, laying birds run under extensive conditions can lay their eggs in a number of places, including the nest boxes provided, the floor of the house, or even the ground outside the house.
When a bird lays an egg, there is a certain amount of eversion of the reproductive tract takes place. If the environment in which the bird is laying its egg is unhygienic, there is the potential for some contaminated material to attach to the everted reproductive tract, which is then taken back into the body, and an infection ensures.
