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The lifecycle of farmed meat chickens

Chickens are sociable, quirky and inquisitive creatures. Descended from jungle fowl, they still possess instincts strongly aligned with seeking shelter in vegetation and roosting up high at night to keep away from predators. A chicken’s natural lifespan can be up to 10 years; but chickens that are slaughtered for meat live for about 35-47 days.

Breeding

Meat chickens are the offspring of breeder stock hatched from eggs which are imported from specialist breeding companies.

Breeder flocks are sourced from eggs that have been produced after an extensive breeding and selection program to create chicken strains that grow and gain weight in a short period of time.

Fertile eggs produced by parent birds at the breeder farms are incubated at hatcheries until the chicks’ hatch.

Breeder flocks are kept in climate-controlled sheds on floors covered in wood shavings or rice-hulls. As breeder flocks approach sexual maturity (18-20 weeks old), they are transferred to laying sheds that include banks of elevated nest boxes. Most sheds provide one nest for every five hens. Usually the sheds have one male to every ten breeder hens.

The welfare consequences of selectively breeding meat chickens to maximise productivity (in terms of growth rate) are apparent even at this stage of the chicken production process. Breeder birds are fed a restricted diet to ensure they don’t become too large to affect their ability to breed. Significant welfare consequences are also seen in the offspring produced by these breeder birds that are grown out for meat.

Hatching time

Fertile eggs are incubated in hatcheries. The incubation of fertilised eggs at hatcheries takes a total of 21 days, and can be divided into two phases. The first stage lasts 18 days, with the eggs being placed on a rack, called a setter, within a climate-controlled room. The setter turns the eggs every hour – mimicking a brooding hen’s natural behaviour. In the next stage, lasting three days, the eggs are transferred to a hatcher, and placed in loose trays. The temperature is increased slightly, to encourage hatching.

After hatching, both male and female chicks are transferred to growing farms. During transport between hatchery and farm, the chicks rely on the nutrients provided by the remains of their embryonic yolk sac to sustain them for the journey.

Chicks arrive on farm

From the hatchery, day-old chicks are transported to growing farms.

It’s here that meat chickens are housed until ready for processing. Typically, the growing of meat chickens is contracted out to farmers – the processing companies own the birds, supply the feed, and provide the technical direction and other support services to the farmer (also known as ‘growers’).

On arrival at a growing farm, day-old chicks are placed in sheds. The chicks’ bedding/litter is usually sawdust, wood shavings or rice hulls. They are first housed in an area called ‘the brooding area’ which is a third to half of the floor space of the entire shed, so that they can quickly find their food and water.

Chicks are generally vaccinated for common diseases such as infectious bronchitis and Marek’s disease. As Newcastle disease vaccination is compulsory for all commercial poultry flocks, chicks are vaccinated at the hatchery or on farm through drinking water at 7 -14 days of age. Pharmacological agents called coccidiostats against necrotic enteritis are routinely added to chicken feed to prevent disease outbreaks in flocks. Antibiotics may also be used by some growers for prevention or treatment of disease.

Growing

Meat chickens are grown indoors in large sheds and may also be provided with outdoor access (free range) systems. However, all chickens are kept inside until they are around 3 weeks of age. On free range farms after around 3 weeks, chicks are allowed outside. This is because chicks need to have sufficient adult feather cover to be able to withstand the outdoor temperature.

At the age of 14 days, after their time in the ‘brooding area’, chicks are given access to the entire floor of the shed. In the shed, the feed and water systems, temperature, lighting and ventilation are all controlled to promote growth. The stocking density for chickens in the shed is calculated on the basis of bird liveweight and the floor space available to the birds in the shed. This is often represented as kg per m2.

In conventional farming systems there are significant welfare issues including high stocking densities, inadequate lighting regimes, insufficient litter, barren environments, and no environmental enrichment or perches.

Does free range and organic mean higher welfare?

Organic farming has a focus on avoiding the use of synthetic chemicals, including synthetic pesticides, herbicides, fertilisers, hormones and antibiotics. In animal production, organic farming may aim to provide a natural environment for animals and usually includes access to the outdoors (free range), but the exact standards of this can vary greatly. Therefore, it is important that consumers look for products that are certified by an independent and reputable organisation and that detailed standards are publicly available.

Processing

What is a spatchock?

Spatchcock are younger meat chickens, and are usually processed at 21 days of age. These chickens are farmed the same way as other meat chickens. The only difference is that they are harvested and processed at an earlier age.

Harvesting and transport

Meat chickens are collected for processing either all at once or in batches depending on the weight requirements of the market.

The process of collecting birds in batches is known as ‘partial depopulation’, ‘thinning out’, or ‘multiple pick-up’. Multiple pick-ups can allow for easier regulation of temperatures inside the shed and the availability of more space for the remaining birds. However, multiple pick-ups cause significant disturbance to birds and disruption to feed and water supply at the time of pick up.

Birds to be sold as chicken, may be picked up as early as 30-35 days and the last at 55-60 days. Pick-ups usually occur at night as it is cooler and the birds are more settled. Birds are usually caught by hand (up to four birds per hand) by ‘pick-up’ crews under low light. They are then placed into plastic crates or transport modules and loaded on trucks for transport to the processing plant.

Slaughter

At the processing plant, chickens are rested in their transport crates or modules for up to 2 hours to allow them to settle from being transported.

Chickens are stunned (rendered unconscious) before slaughter. In Australia, stunning occurs either by electrical waterbath stunning or controlled atmosphere (gas) stunning. Chickens have to be removed from their crates and be consciously shackled for the electrical stunning process. For gas stunning, birds are not consciously shackled but either remain in their crates or are transferred to a conveyer system that takes them through the gas. Once unconscious, the bird’s throat is cut allowing the bird to bleed out and die.

Electrical waterbath stunning in particular have associated animal welfare issues including the need to shackle birds while they are conscious and a higher risk of ineffective stunning than other systems. To read more about the animal welfare issues of meat chickens at slaughter, click here.

Once chickens are dead they are then plucked, cleaned and further processed either as whole birds or cut into pieces such as drumsticks, breasts, wings and thighs. They are then packaged for sale.

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Updated on March 17, 2020
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https://kb.rspca.org.au/knowledge-base/the-lifecycle-of-farmed-meat-chickens/

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