Chicken handling and processing must always be done in a professional and hygienic manner.
Broiler farmers need to ensure the quality of the birds from catching, handling, transport, and processing are safeguarded all through to ensure production of the high-quality carcass with as few rejections as possible.
Here are tips to maximise high yields and at the same time protect the welfare of the animals before slaughter.
1. Feed withdrawal
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It is important to withdraw feed eight to 12 hours before the birds are slaughtered.
This gives the gut time to clear all the ingesta in the lumen through digestion and assimilation and defecation prior to slaughter.
This exercise will reduce contamination of the carcass with ingesta and guarantee good quality carcass with good keeping quality.
Equally feed should not be withdrawn too early as this will affect the quality of the liver and the intestines leading to liver rejections as they will appear ‘cooked’.
Birds will also lose an extra 0.1-0.5 per cent of the body weight per hour, a process called shrinkage.
For that reason, birds should not be held longer than necessary prior to slaughter.
The withdrawal period, therefore, encompasses the time without feed, catching time, transport, and holding period at the plant before slaughter and it should not exceed 12 hours.
2. Humane catching and transport
Introduce 23 hours of light, three days before slaughter to calm the birds during catching.
The light intensity should be about 10 lux (equivalent to one candlelight) and preferably blue during catching.
This will reduce the incidences of sudden deaths during catching.
The birds should be carefully loaded in well-ventilated trucks and quickly transported to the plant without unnecessary stoppage. It is good to transport the birds at night.
3. Reduce any fractures during catching and slaughter.
Many of the downgradings of carcasses occur during catching.
Therefore, this process must be well planned, making sure that you have trained catchers who will be carefully supervised to avoid unnecessary rejections.
When catching, the birds should be held carefully by holding both shanks or around the body using both hands, pressing wings against the body to avoid bruises, wing damage, and internal bleeding due to fractures.
It is good animal welfare practice to stun birds (rendered unconscious and unaware of pain) before slitting the throat.
Under-stunning will lead to wing flapping hence defects, bruising, and breaks.
Over-stunning using electricity will cause internal carcass damage, broken bones especially wishbones, and red tips on the wings.
4. Avoid overscalding
After slaughter, completely immerse the bird in hot boiling water to soften feathers making it easier to pluck and remove any soil or organic material on the skin.
Plucking can be done by hand or using mechanical finger pickers available in the market.
The ideal temperature is 50- 57 degrees centigrade and should be done within 2.5-3.5 minutes.
Too hot temperatures will cause cooking of underlying tissues and make the meat appear white and will be rejected by customers.
Underscalding will result in microbial persistence and lack of feather picking and removal of the skin.
5. Ascites
Ascites in chickens, commonly referred to as water belly, represents a spectrum of physiological and metabolic changes leading to the excess accumulation of fluid in abdominal cavity.
Ascitic birds come from poor brooding conditions.
It is due to more demand for oxygen due to fast growing birds and yet the ventilation is compromised to avoid chilling effect.
Such birds develop swollen abdomen full of fluid mostly plasma from the blood vessels, commonly referred to as ‘waterbelly’.
The carcasses of such birds are wholesomely condemned. Good brooding practices is therefore vital to minimise whole bird rejection.
6. Very small birds
Poor growers of less than 800g dressed weights are always rejected in the market. Flocks must therefore be uniformly managed to live weights mostly preferred by the specific markets.
7. Recovery of gizzard, hearts, liver and feet
Remove all the internal organs from the upper buccal cavity, wind pipe, esophagus, crop, gizzards, liver spleen and intestines carefully without spilling the contents.
If the market demands, you should be able to recover 80 per cent of the liver, gizzard and heart.
A cut is made at the base of the tail above the vent from where a hand is introduced to grab the large intestines and other internal organs.
Next, clean them in potable chlorinated water to reduce any form of unintended contamination of the carcass.
[The writer is a head vet at Kenchic]
