The standard methods for capture and caging of broilers pre-slaughter, and the loading and unloading of the chickens at the farm and the slaughterhouse are noisy. This results in chickens experiencing stress, which can affect the final quality of the processed bird.
Among factors contributing to this stress is the use of motorized equipment, such as forklift trucks. Forklift trucks raise noise levels, and this is particularly the case when used in closed poultry houses.
The harmful effects on broilers of raised noise levels are an increase in blood flow to the thighs – a physiological response designed to help chickens escape from the source of stress.
While the birds may relax on the way to the processing plant, on arrival they are usually unloaded by forklift trucks, with a consequent increase in noise, and so the “flight” response reoccurs, and blood is pumped to the wings and legs.
If there is a delay pre-slaughter, blood will be pumped away from the extremities, alleviating this problem. However, when birds leave the plucker, there may still be a slight pink color to the thighs and wings. While in many plants, this is considered unimportant, in others it is deemed a quality issue and birds cannot be classified as Grade A.
There is, however, an alternative to the traditional method of harvesting birds that does not rely on the use of forklift trucks with their associated noise, and results in less stress for the broilers.
A quieter harvesting method
The alternative approach to harvesting has three main elements:
- A retractable hydraulic arm ending in a fork, similar to that of a forklift truck.
- A track system of metal pipes with connections that do not impede the movement of cages or pallets that will move over them.
- Two winches, one used to deliver cages at the start of the track system and the other at its end.
Most poultry houses where forklifts are used as part of broiler harvesting are built with large doors in the east and west walls. In the example below, it is assumed that birds will be collected from the west end of the house, and this is where the truck with the cages and/or pallets needs to be parked.
Alongside the truck with the empty cages, a smaller truck with the hydraulic arm needs to be parked, and is used to unload the cages and place them onto the network of metal tubes that has been laid out inside the poultry house running parallel to the sides of the house.
If a poultry house is, for example, 12 meters wide, two enclosures should also be erected, each of about 1.5 meters in width, leaving a passageway through the middle. Having the birds already enclosed in this way prior to the arrival of the cages will not only speed up the capture process, but reduces the risk of harming or killing any birds during harvesting.
Once the batch of cages has been loaded onto the network of pipes, it is gradually moved into and through the house. Once the cages are filled, a second winch is used to remove them from the house. Each of the cages should be connected to each other so they move much very much like a train on a track.
The hydraulic arm can then be used to load the filled cages onto the truck. Once the truck arrives at the processing plant, this arm can be used to quickly unload them.
More advantages than stress reduction
In addition to reducing the stress endured by the broilers during harvesting, there are several other benefits to using the track-and-winch system.
This system requires a smaller investment than using forklift trucks, which not only requires the purchase of forklifts for use at the poultry farm and at the processing plant, but also spare parts and peripherals, such as batteries and charging stations.
Where workers are concerned, operating a hydraulic arm is easier than operating a forklift truck. For example, the forklift truck’s driver must always be vigilant to prevent accidents and to avoid harming the birds.
Given that a hydraulic arm is a simpler piece of equipment than a forklift truck, less maintenance is required.
Winches, rather than a forklift truck, offer a quieter, and hence less stressful, way to deliver cages to and remove birds from the broiler house.