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. Meat chickens, also called broiler chickens, are those that are grown for their meat, as opposed to laying eggs. A chicken’s natural lifespan can be up to 10 years; but chickens that are raised for meat live for about 35-47 days.
How is the meat chicken industry structured?
The majority of chicken meat in Australia is produced by a handful of vertically integrated companies. These companies (known as processors) own and operate the breeder farms, hatcheries, feed mills and processing plants. However, typically the growing of meat chicken is contracted out to independent contract farmers (growers). The processor company will own the birds and provide feed, veterinary and technical support, as well as arrange for the birds to be caught, transported and processed at the abattoir. The grower owns the farmland, farm infrastructure (e.g. sheds and equipment) and is responsible for caring for the birds while on the farm, including providing all necessary inputs such as water, bedding/litter, labour as well as gas and electricity.
Meat chickens are the offspring of breeder stock hatched from eggs which are imported from specialist breeding companies overseas.
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 breeder birds’ offspring who are grown out for meat.
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 in climate-controlled trucks. 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, chicks are transported to growing farms. It is here that meat chickens are housed until ready for processing.
On arrival at the farm chicks are placed in the sheds, where up to 60 thousand birds may be housed in one shed. Chicks are first placed in an area called ‘the brooding area’, a heated and well-lit 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. The floor of the shed is covered in bedding/litter which is usually sawdust, wood shavings or rice hulls.
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.
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. This is because chicks need to have sufficient adult feather cover to be able to withstand the outdoor temperature. On free-range farms, after around 3 weeks when birds are reasonably feathered, they are allowed outside.
At around 14 days of age, 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 (usually represented as kg per m2) for chickens in the shed is calculated on the basis of bird liveweight and the floor space available to the birds in the shed.
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.
Meat chickens are typically slaughtered between 4-6 weeks of age. Depending on the weight requirements of the market, meat chickens may be ready for slaughter as early as 30-35 days (whole birds) and up to 55-60 days (chicken pieces). If birds are to be sold as spatchcock (younger meat chickens), they are usually slaughtered around 21 days of age.
Harvesting and transport
Meat chickens are collected for processing either all at once or in batches depending on the weight requirements.
The process of collecting birds in batches is known as ‘partial depopulation’, ‘thinning out’, or ‘multiple pick-up’. It is not uncommon for a shed to go through a number of pick-ups before being completely depopulated, cleaned and then prepared for the next batch of chicks to arrive. 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.
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.
Once at the abattoir, 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 has 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 dead, chickens are 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.