Hatchery to farm
Newly hatched chicks are transported to broiler farms, in ventilated chick boxes, in air-conditioned trucks that are specifically designed to carry chicks. It is important that chicks receive feed, water and warmth soon after hatching, however the remains of the yolk sac can sustain each chick for up to 72 hours post-hatch.
Brooding or Starting
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 (referred to as brooders) for about three weeks. This period of time is called brooding. 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.
The air temperature under the brooder should initially be 35oC and reduced by 1-2oC per day until it reaches 23oC when the chickens are approximately three weeks of age. Sophisticated brooding systems have been developed which include gas-fired radiant heat sources, through gas-fired hot air blasters, and fully controlled environment sheds with special heated air passed through ducts to the chickens. High protein (22%) starter rations are fed to young meat chickens to ensure they grow as much as possible early in life. This may be continued for 18-24 days. A medicine, called a coccidiostat, is added to the feed of meat chickens to prevent the intestinal disease coccidiosis. Australian meat chickens are raised on litter floors, but some overseas companies use wire-floored cage systems. The number of chickens in a meat chicken shed is usually high, with some Australian sheds containing up to 30 000 meat chickens.
Growing or Finishing
At this stage, growth is still very important, but since feed is expensive careful costing is carried out to keep expenses to a minimum. Thus a diet that is lower in protein (19%) is fed to the chickens for the remainder of their life (usually until 42 days of age). Heavy weight birds that are required for chicken fillets are slaughtered at up to 56 days of age. A coccidiostat, sometimes a different one from that used in starter feed, is added to the finisher feed. Some meat chickens go through a separate rearing stage, with a special rearing ration being fed to them before they are placed on a finisher feed, but most go straight from starter to finisher feed.
Getting finished meat chickens from the farm to the factory is a delicate business. Most catching is done at night when the birds are quieter, and this also gets them to the processor early in the morning with less delay before slaughter. Delay means stress and weight loss. Mechanical devices for harvesting meat chickens have been invented, however results are variable and most Australian meat chickens are still caught by hand. Birds are 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. In Australia, a percentage of chickens are harvested at up to four different times depending on the need for light or heavy birds. Harvesting is also know n as ‘partial depopulation’, ‘thinning out’, or ‘multiple pick-up’. Thinning out sheds allows more space for the remaining birds and reduces the natural temperatures in the shed. The first harvest can occur as early as 30-35 days and the last harvest at 55-60 days.
Broiler processing is highly mechanised
Once all the birds have been harvested (after approximately 60 days), the shed is cleaned and prepared for the next batch of day old chicks, which generally arrives five days to two weeks after the previous harvest. Not only does is the time between batches used to clean the shed, but it also reduces the risk of common ailments being passed between batches as many pathogens die off in this time. Many farms undertake a full cleanout after every batch. This involves 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.
Once the shed has been thoroughly cleaned, it is disinfected. This is carried out using low volumes of disinfectant sprayed throughout the shed. If insects, such as beetles, were a problem in the previous batch an insecticidal treatment may also be used. Any disinfectant or insecticide that is used must be approved by the Australian Pesticide and Veterinary Medicines Authority (APVMA) as safe and fit for use in broiler sheds. After a full cleanout, company veterinarians or servicemen will test the shed to confirm that it has been adequately cleaned and any potential disease agents removed. Sometimes, a partial shed cleanout only is required which involves removing old litter and / or topping up fresh litter and cleaning and sanitising equipment. However, a full cleanout is done after every second or third batch of chickens.
When chickens arrive at the processor they go through the following sequence:
- Hung by the legs on a shackle
- Stunned using an electrically charged water bath
- Killed by cutting the blood vessels in the neck
- Bled so that most of the blood leaves the carcass
- Scalded to soften the attachment of the feathers
- Plucked to remove the feathers
- Head removed
- Gutted or eviscerated to remove the internal organs
- Washed to remove blood and soiling from the carcass
- The hock is cut to remove the feet
- Chilled to prevent bacterial spoiling
- Drained to remove excess water from the carcass
- Cut selection to divide the carcass into the desired portions (breast, drumsticks etc.)
- Packed in plastic bags to protect carcasses or portions
- Chilled or frozen for storage
Removal of breast meat
The carcasses are graded during the processing sequence to remove poor quality meat. This meat is used for cut-up (further processing) purposes or, if badly affected, might be used for pet food or condemned and cooked to be made into meat meal for stock feed.
Further Processing and storage
Further processing includes cutting up the carcasses into portions, deboning carcasses and preparing special ready-to-cook products. Cooking is an additional process which is carried out at some processing plants. Almost all chicken meat is sold chilled. Chilled chicken meat must be cooked before it spoils. The shelf life of chicken meat is usually eight to 12 days, depending on the processing, handling and storage conditions.
In Australia most chicken is sold under the brand name and market competition is very strong. The average amount of chicken eaten has risen rapidly as prices have fallen. These changes have taken place at the expense of the beef and lamb industries.