Food

1. Carcass Dressing
FST-306 3(2-1)
Dr. Muhammad Issa Khan
Associate Professor
National Institute of Food Science and Technology
University of Agriculture, Faisalabad

2. Stunning
• Stunning is process of making animals unconscious before
slaughtering so that they can bleed without causing pain
Mechanical stunning
Chemical stunning
Electrical stunning
Mechanical Stunning
• It is considered to be one of the oldest stunning technique
as pistols were used to stun animals prior to the concept of
humane slaughtering
• Modern mechanical method of stunning is captive bolt
• It can be penetrative or non-penetrative

3. • Penetrative bolt drives into the skull and causes
unconsciousness both through physical brain damage and
concussive blow to the skull
• Non-penetrative stunner is 'mushroom-headed' and
impacts on the brain without entering
Chemical Stunning
• Animals are exposed to breathing mixture by moving
through a room that results in unconsciousness and is a
kind of chemical strangulation
• Carbon dioxide is used @ 80-90% by volume but its higher
level inside body is harmful
• Carbon dioxide is acidic in nature so it is pungent at level
above 30% and being potent respiratory stimulant
• Lower the concentration of O2 cause stunning by anorexia

4. • So modification in gaseous mixture is made to lower
concentration of CO2
30% by volume CO2 and 2% oxygen in argon, nitrogen
or inert gasses
2% oxygen in argon, nitrogen or inert gasses
Electrical Stunning
• Electrical stunning is accomplished by passing electric
current through brain and heart of the animal
• Pair of scissor-like tongs with circular or rectangle
electrodes immersed in saline solution is used for applying
current to animal
• Current passing through brain results in an immediate
convulsion

5. • A current of 50Hz frequency for not less than 7s is applied
• Animal will require 30-40 seconds recovery time during
which it is slaughtered
• Three phases in animal’s reaction to electrical stunning
Violent contraction of all voluntary muscles and
respiratory arrest
After 10 s the muscles relax and animal lies flaccid
The animal starts walking movements and respiration
starts again after 45-60 s of current disconnection

6. Skinning
• The skin removal process of animal is called as skinning
and it is done to prepare muscle tissue beneath it for human
food consumption
• Case skinning
• Open skinning
Case Skinning
• The removal of skin like sock from animal body is called
as case skinning and is possible if animal is stretched
• The skin of small animals is removed by this method
• Animal is hanged upright by its feet

7. • A cut is made on one foot and continued up to around the
anus and down the other leg
• Skin is pulled down the animal to remove skin like a
sweater
Open Skinning
• The process of skin removal from animal in the jacket form
is called as open skinning and is used if skin to be tanned
immediately or frozen
• Large animals are normally used to be skinned by this
method
• The animal is placed on flat surface for open skinning and
a cut is made from anus to lower lip and up the legs to
open and remove the skin
• The final step of the process is removal excess fat or flesh
with skin with blunt knife

8. Evisceration
• The microbial quality of dressed carcasses depends upon
• Skill level of person
• Plant physical conditions
• Animal type
• The operator skills are required in the critical evisceration
step to avoid puncture of viscera to protect carcass from
fecal contamination
• The abdominal cavity of animal is opened by cutting in
middle down the brisket
• Liver is removed from diaphragm
• The carcass is fully hoisted so that viscera fall out by gravity
under their own weight

9. • The chances of carcass microbial contamination may be
reduced by trimming the excessive tissues
• Later, the carcasses are washed thoroughly with the jet of
water
Carcass Dressing
• The dressing is set of processes staring from slaughtering
to remove hide, viscera and appendages from animal for
final inspection
• The objective of carcass dressing is to remove damaged
and contaminated parts and to standardize the carcass for
presentation
• The hygienic dressing of carcasses requires that:
 Hide should never come in contact with skinned surface
 Blood should not come in contact with hide or carcass
 Operator should not be in contact with skinned surface

10. Carcass Dressing Percentage for Different Meat Species
Animal Species Average Dressing % Dressing Range %
Lamb/Goats 50 49-52
Cattles 62 57-64
Broiler 71 70-72
Turkey 79 77-81

11. Carcass Inspection and Evaluation
• The carcass and viscera inspection and evaluation is done
immediately upon completion of slaughter process
• Carcass should retain its identity with its removed organ
and offal
• The inspection is carried out by authorized veterinarians or
meat inspectors
• The inspectors visually examine organs and tissues of
animal, palpate and do incision for physical examination
• The disease status is checked by incision of lymph nodes
with considerable attention
• In diseased animal the lymph nodes swell and its color is
changed

12. • The lesions in carcass are linked the conditions of animal
suffering from pneumonia and tuberculosis
• The cysts in liver, heart and muscle are result of parasitic
disease caused by tapeworm
• The lining of thoracic cavity and abdominal cavity
inflammation are indications that animal are suffering from
infection
• The country has its own laws and regulations regarding
inspection and evaluation
• A country without efficient inspection and evaluation
systems face the problems of food safety