Processing operations can be broken down into specific areas, and procedures applied to each to maximize efficiency and speed workflow. But are processes implemented as they should be?

It is all very well to have procedures in place, but they must be properly applied and ensure that they are actually achieving the results they were designed to achieve.

The following areas in particular are worth thorough examination.


Birds should be harvested with care so as not to damage them, but if they are then put into damaged or defective cages, problems can occur.

It is worth checking to ensure that cages are not broken. They may not have doors because they have been removed by the harvesters, as opening and closing the cage door can slow down the speed of work. Many companies turn a blind eye to this.

Even when transport cages do have doors, often they are ill-fitting and fall down into the cage itself, or it could be the case that the size of the cage is not adequate for the size of the bird.

Any of these factors can harm birds or result in suffocation.

Preparation for transport  

Even when birds are handled with utmost care at harvest and placed into the best possible cages, risks remain. As trucks are piled ever-higher with bird-filled cages, inevitably those birds toward the bottom and the middle of the stack will have a reduced air supply and this can result in suffocation.


When trucks leave the farm, it should always be remembered that what they are carrying is the investment of the company. If they are not properly equipped with air conditioning, birds will die, reducing the amount of meat available for processing. The lower the amount of meat processed, the higher the cost per kilo, and the lower the profit.

Waiting at the plant  

If there is no suitable receiving area at the processing plant, birds will remain on the trucks, which could be parked in full sunlight. When this occurs, the mortality rate increases.

Birds awaiting slaughter will remain in relative comfort if specific conditions are met: There must be adequate ventilation, suitable space around the stacks of cages to ensure the free-flow of air, and darkness.

Yet, even when the above conditions are met, if when birds reach the hanging area there is a high light level, their stress levels will rise prior to stunning.

Hanging the live birds  


The route to the stunner should have reduced levels of lighting; however, in some plants this area is completely open. Once birds have been hung on the overhead conveyor they will start to flap, and if their wings hit against metal surfaces, they can be damaged. This situation is exacerbated when no breast comforter has been installed.

Incidentally, should the time between hanging and entering the stunner exceed 30 seconds, blood will accumulate in the wings and neck. Should bleeding time be insufficient then, following plucking, the wings will have some blood at their tips, affecting this area of the processed birds.


Should the access ramp to the stunner be wet, and if there is electricity flowing through this water, then chickens well suffer a pre-shock. When this occurs, birds lift their heads and flap as they pass through the water bath, leaving them totally conscious. When this occurs, they must be taken down from the conveyor and returned to the hanging area.

Should this situation arise frequently during the shift, then extra working hours will be needed, thus raising the costs of the plant.

Prewash before scalding  

When chickens are slaughtered, there is fecal material on their feathers and skin, which is not acceptable from a sanitary perspective. Because of this, they should be washed to remove the maximum amount of fecal material. While this practice does occur, it is often performed with insufficient volumes of water, resulting in the water becoming dirty, and the level of potentially contaminating bacteria rising.


The reason for scalding is to raise the body temperature to such a degree that the skin follicles dilate and the feathers are loosened. Yet the efficiency of this process can be reduced if the time spent moving birds from the scalder to the plucking machine is too long, allowing cooling to occur. This can affect the quality of plucking.


Chickens should enter the plucking machine at a high enough temperature to keep the follicles open. If the water used during scalding is not hot enough, birds will reach the plucker at lower than ideal temperatures for feather removal. When this occurs, it may be necessary to shut down the plucking machines. At the moment that this occurs, the pressure of the plucking fingers on the skin increases, aiding the entry of fecal material into the follicles, and raising the risk of cross-contamination. Additionally, some fat from the skin may be removed, reducing yield.


Evisceration is carried out to gather the organs and other parts fit for human consumption at the speed of the overhead conveyor. If, for whatever reason, these parts are not sent immediately to the chillers, then bacterial growth may occur, which reduces shelf-life.

Chilling carcasses and giblets  

Plant managers must keep water temperatures as close as possible to 0C to ensure that these products leave the chiller with an average temperature of 2C. However, when bottlenecks occur, there is the possibility that with an increase in temperature, there will be a loss of moisture from the meat.


Once carcasses have been drained and selected by weight, they need to be placed into their respective bins, but if this process is not carried out fluidly, then bottlenecks can occur. Once this happens, and temperatures start to rise, there is again the possibility that moisture will be lost, affecting yield.


The ideal would be that carcasses and giblets enter the coolers at a maximum temperature of 4C. Should this temperature rise as result of, for example, accumulation of product at the chiller entrance, the time needed for chilling will also increase. This can lead to a darkening of the skin due to greater exposure to cold air.

A lot can be gained by paying attention to the little details along the production chain, to ensure that that highest quality and safety standards are met, helping to reach maximum yield.