Commercial meat chicken farms are intensive, highly mechanised operations that occupy relatively small areas compared with other forms of farming.

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Growing Meat Chickens

Broiler Farm

Most commercial meat chicken farms are intensive, highly mechanised operations that occupy relatively small areas compared with other forms of farming.

Commercial broilers are run on litter (e.g. rice hulls, wood shavings) floors in large poultry sheds. THEY ARE NOT KEPT IN CAGES in all of the production systems used in the industry. The main production systems are generally referred to as conventional, free-range and organic. 

Hatchery to farm

Chicks are transported from the hatchery to broiler farms, usually in ventilated chick boxes in specially designed, air-conditioned trucks. Although the remains of yolk sac taken into its abdomen at hatching contains nutrients and moisture to sustain the chick for up to 72 hours, it is important that chicks receive warmth, feed and water within a reasonable time of hatching.

Shedding

Meat chickens are farmed in large open poultry houses, usually referred to as ‘sheds’, ‘houses’ or barns, but sometimes as ‘units’. Shed sizes vary, but a typical new shed is 150 meters long and 15 meters wide and holds about 40,000 adult chickens.

The larger sheds can contain up to 60,000 broiler chickens. There are often three - ten sheds on the one farm. A typical new farm would house approximately 320,000 chickens, with eight sheds holding approximately 40,000 chickens/each.

Traditionally, broiler sheds in Australia have been ‘naturally ventilated’, with the sides of the shed open to fresh air. The amount of air circulating through the shed is changed by raising/lowering curtains running along the side of the shed, or by a vent opening at the top of the shed. Fans encourage air flow, and water misting systems cool birds by evaporative cooling in very hot conditions.

An increasing number of chicken sheds in Australia have ‘tunnel ventilation’.

Tunnel ventilation sheds have fans at one end of the shed which draw air into the shed through cooling pads in the walls, over the chickens and out the fan end of the house at high speed. Three or four temperature sensors in the poultry house allow the fan, heating and cooling settings to be adjusted as often as every three minutes.

Feed lines and pans run the length of the shed and are supplied automatically by silos from outside. 

Water lines run the length of the shed, with drinkers at regular intervals. 

Water and feed are placed so that chickens are never more than about 2 metres from food and water. 

Rearing the chickens

·      Spreading a thick layer of clean and fresh litter, such as sawdust, wood shavings or other material such as rice hulls across the floor for bedding for the bird.

·      Preheating the shed

·      Checking feed and water systems.

On arrival at the broiler farm, day-old chicks are placed onto the floor of the shed, where they are initially confined to an area of between a half to one third of the total shed area (the ‘brooding area’) and given supplementary heating from gas heaters or heat lamps.

This is called brooding and the heaters are referred to as brooders. Extra feed pans and water dispensers are provided in the brooding area, and the bedding may be partly covered with paper to stop dropped feed from getting into the bedding and spoiling.

Both male and female chicks are reared as meat chickens. While the flocks are usually of mixed sex, some operations may grow male and female chickens separately, depending on market requirements. For example, one company grows out only male chickens in one area, allowing its operations and processing plant in that area to be geared up specifically for larger birds, while sending female chicks to another area.

For the first two days of the flock’s life, the shed temperature is held at 31 - 32ºC, the optimum temperature for baby chick comfort, health and survival.

As the chickens grow, they need less heat to keep them warm, so the temperature of the shed is gradually lowered by about 0.5°C each day after the first two days, until it reaches 21 - 23°C at 21 days. The farmer aims to maintain shed temperatures within this range, although in sheds of large birds towards the end of grow-out, the temperature may be reduced.

Shed temperature and humidity can be managed by altering ventilation and using stirring fans and water mists. Air quality is also managed by varying shed ventilation.

Depending upon ambient conditions, the brooders will be removed at some time between 4 and 14 days.

As the chickens grow, the area available to them is increased until they have free run over the floor of the entire shed.

Generally, feed and clean water is available 24 hours a day, although some operators make feed available at specific 'meal times' only. This practice may stimulate better digestion, improve bone strength and prevent birds from becoming over fat.

The chickens have adequate lighting to see by and to find feed and water, with dark periods each day to allow them to rest. The lighting provided is usually dimmer than natural lighting to promote calm.

Shed temperature, humidity and air quality are checked and adjusted regularly, either manually by the farmer or automatically by computer controllers.

The farmer also checks his flocks regularly to monitor the flock’s health and progress, remove any dead birds, and cull any sick or injured ones.

Farmers also check feeders and waterers. Careful management of ventilation and waterers helps keep the litter clean and dry, as poor litter affects air quality and can affect bird health and performance.

Over the life of the broiler flock only about 4% of chickens are lost. This is through natural causes or selective culling.

Harvesting the meat chickens

In Australia, a percentage of chickens are harvested from most flocks on several occasions. Harvesting, also known as ‘partial depopulation’, ‘thinning out’, or ‘multiple pick-up’, may be done up to four times, depending on need for light or heavy birds. Thinning out sheds allows more space for the remaining birds and reduces the natural temperatures in the shed.

The first harvest might occur as early as 30-35 days and the last at 55-60 days.

Chickens are often harvested at night as it is cooler and the birds are more settled. They are generally picked up by specialised contract ‘pick-up’ crews under low lighting conditions so that they are calm and easy to handle. They are usually caught by hand and placed into plastic crates or aluminium modules designed for good ventilation and safety from bruising during transport. These crates or modules are handled by specialist forklift equipment and loaded onto trucks for transport to the processing plant.

Cleanout

When all the birds have been removed from the shed (after about 60 days), it is cleaned and prepared for the next batch of day old chickens.

The next batch generally arrives in five days to two weeks, giving time to clean the shed and prepare for the next batch. The break also reduces the risk of common ailments being passed between batches as many pathogens die off.

Many farms undertake a full cleanout after every batch. This includes removing bedding, brushing floors, scrubbing feed pans, cleaning out water lines, scrubbing fan blades and other equipment, and checking rodent stations. High pressure hoses clean the whole shed thoroughly. The floor bases are usually rammed earth and because low water volumes are used, there is little water runoff.

The shed is disinfected, using low volumes of disinfectant which is sprayed throughout. An insecticidal treatment may be applied in areas where shed insects such as beetles are a problem and may threaten the next batch.

Company veterinarians or servicemen may test sheds after a full cleanout to confirm sheds have been adequately cleaned and potential disease agents removed.

On other farms, a partial clean up of the shed is done, including removing old litter and/or topping up fresh litter and cleaning and sanitising equipment. A full cleanout is done after every second or third batch of chickens.

Number of Batches a Year

As each broiler flock spends 6-7 weeks in a shed and there is a two week break between batches, farmers run about 5.5 batches through a shed each year.

Farm Biosecurity

Farmers take precautions to prevent entry of diseases onto broiler farms. 

People can carry disease on their footwear, clothing, hands and even vehicles, so growers take steps to minimise the risks they pose. These may include:

·      signage and gates at access points to the farm to discourage unauthorised entry

·      requirements for visitors and service providers to wear overalls and boots provided by the farmer

·      disinfecting footwear in foot washing baths at the entrance of each shed

·      minimising vehicle movements, and requiring vehicles or equipment that have visited other farms to be washed down 

·      scheduling movements so that where people or vehicles must go between farms on the same day without a thorough disinfection, the youngest flocks are visited first and the oldest last.

·      As wild birds can carry disease, keeping birds and their droppings away from chickens is important. Prevention measures include:

·      netting the sheds so they are wild bird proof

·      not allowing farmers and their employees to keep birds of any type including budgies or parrots as pets

·      cleaning up spilled feed promptly to discourage visiting birds

·      where practical, not having dams that would attract water birds

·      sanitising chicken’s drinking water if it could be contaminated by wild birds (eg dam or river water).

·      Farmers have documented pest control programs to reduce the risk of diseases being carried on to the farm by rodents.

Strict records are kept by the farmer of the chickens’ health, growth and behaviour, so that any emerging disease problem can be identified rapidly and acted upon. 

Growth Rates

A number of factors affect the chickens’ growth rate and size at harvest. These include: 

·      Breed

·      Age at harvest

·      Feeding regime

·      Gender (males grow faster)

·      Age of parent flock (ageing flocks produce bigger eggs and the chicks from larger eggs grow faster)

Why do chickens grow to market weight so quickly?

Most of the improvement in growth rates over the last 50 years ago is due to improved breeds of chicken. This genetic gain, which has been achieved through conventional selective breeding, is due to:

·      investment in advanced breeding programs by the large well-resourced specialist breeding companies overseas

·      the number of generations that can be produced in a relatively short period of time. Chickens reach sexual maturity at about 20-25 weeks of age, then take only three weeks to start producing the next generation. Each hen can produce up to 150 progeny within a year of its own hatching).

A further improvement in growth is due to improved nutrition. For current meat chicken breeds, the precise profile of nutrients such as energy, protein, essential amino acids, vitamins and minerals that the chicken needs at each stage of its growth has been studied precisely.

For each feed ingredient, the levels of these nutrients digestible by the chicken has also been established. With this information, feeds can be formulated to match the chicken’s precise nutritional requirements throughout its life cycle, thereby optimising growth.

Other gains made in meat chicken growth and performance are due to better husbandry techniques and health management.

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