Module 6. Meat and poultry processing

 

Lesson 20

PRE SLAUGHTER HANDLING AND INSPECTION OF ANIMALS

 

20.1 Introduction

Pre-slaughter handling of meat animals includes procedures adopted during transportation, pre-slaughter rest and ante mortem inspection.  

20.2 Transportation of Meat Animals

Animals are taken to the slaughter house either on hoof or through road/rail/sea transport. Whatever the means, what is of paramount importance is that the animals must not be subjected to cruelty. There are legislations against cruelty to animals and procedures recommended need to be strictly adhered to. If the animals are carried by road or rail care needs to be taken to avoid overcrowding which may lead to suffocation and physical injuries in the form of bruises, fractures etc. Tying or chaining of the animals is to be avoided. There are specially designed trucks and wagons available to take care of such issues and should be used as far as possible.

20.3 Pre-Slaughter Rest

·       Pre-slaughter rest is the period before slaughter when animals are rested in order to improve the meat quality and reduce the chances of contamination with gastrointestinal bacteria. 

·       During pre-slaughter rest fatigue could have negative influence on protective functions of the animals (low immunity) allowing rapid penetration of the microorganisms especially E Coli through mucous membrane of the intestine to the blood stream and ultimately to the organs.

·       Normal feeding and resting for 48 hours brings gradual freeing of muscles and other organs from microorganisms, improve bleeding and keeping quality of meat.

·       Pre-slaughter rest also helps in preserving glycogen level in the muscles and during the later phase this glycogen undergoes anaerobic respiration and results in production of lactic acids which has mild preservation effect on meat quality

·       Under stressed conditions muscles do not receive enough oxygen which leads to higher lactic acid production often associated with comprised quality in terms of colour, texture and water holding capacity.

20.4 Ante-Mortem Inspection

It refers to inspection of food animals conducted prior to (12 to 24 hr) slaughter to ascertain fitness or otherwise of the animals for slaughter.

20.4.1 Objectives of ante-mortem inspection

1)      To detect the animals suffering from infectious or scheduled diseases (communicable to animals or human beings) such as FMD, Rabies, Anthrax, etc.

2)      To detect diseases causing toxic or infectious conditions and which may escape detection in post mortem examination.

3)      To prevent outbreaks of food poisoning resulting from the consumption of meat from animals which were ill at slaughter

4)      To make post-mortem inspection more efficient and less laborious.

5)      To document information on animal diseases prevalent in the region.

To prevent the use of meat from animals suffering from febrile condition.

20.4.2 Facilities for conducting ante-mortem inspection

1.      For successful ante-mortem examination, procedure for adequate identification of the animals to be slaughtered need to be followed.

2.      The lairage should be properly designed, well lighted and ventilated

3.      The lairage should have provision for isolation pens

4.      There should be competent assistant staff for handling of livestock and above all a competent veterinary officer must be available.

5.      A well designed code on veterinary ante-mortem inspection procedures, judgement principles and documentation of findings need to be maintained.

20.4.3 Procedure for ante-mortem inspection

Immediately after the animals arrive at the slaughterhouse, they are examined by qualified veterinary personnel before being sent to the lairage where ante-mortem inspection is carried out 12 to 24 hours before slaughter by the qualified veterinarians.

Ante-mortem inspection can be carried out in two stages:

20.4.3.1 Stage-I: General examination

The animals are to be examined collectively to assess the overall health status so as to segregate them into three groups:

1)      Healthy

2)      Unhealthy (diseased)

3)      Apparently healthy (doubtful cases)

·      The animals are examined while they are at rest and also in motion

·      They are observed for the gait, posture, fatigueness and for their response to external stimuli.

·      They are examined for abnormal behavior like walking in circles, state of alertness, symptoms of tiredness and agitation

·      Animals are examined for abnormal discharge from natural orifices like eyes, nose, mouth, anus, vagina etc. and/or swellings on any part of the body.

·      It is also important to observe for any evidence of cruelty to animals such as any sign of bruises, torn skin, and fractured bone indicating carelessness during transportation.

At the end of the first stage of examination, healthy animals are cleared as “fit” for slaughter whereas the other two groups are taken to the next stage of examination.

20.4.3.2 Stage-II. Detailed clinical examination

The animals classified as unhealthy (diseased) are subjected to further examination to correctly diagnose the illness while the animals placed in group three (Apparently healthy or doubtful cases) are examined to ascertain whether these animals are really sick and if so what could be the nature of illness.

Animals are subjected to the following investigations:

(i)        Temperature, pulse and respiration rate should be recorded and animals suffering from fever must be retained for treatment preferably outside the meat plant.

(ii)      The lymph nodes are palpated and examined for any swelling and abnormalities and on this basis the animals are either rejected or passed with clear instructions for careful post-mortem examination

(iii)    Pregnant animals or animals having delivered a calf within the last 48 hours are not permitted for slaughter. Animals undergoing treatment or with a recent history of treatment as also experimental animals are not to be slaugthered unless a ‘no objection certificate’ has been issued by veterinarians.

(iv)    Blood, urine and faeces samples to be drawn for laboratory tests

(v)      Pathoganomonic clinical symptoms of the diseases for suspected animal to be carefully studied.

(vi)    The species, class, age, condition, colour and markings re recorded in case of diseased or sick animals and in case of the animals in poor condition.

Table 20.1 Diseases and abnormalities encountered in ante-mortem inspection

General conditions

Specific infections

Cattle

Calves

Sheep

Swine

Moribund and exhausted status

Actinomycosis

 

Immaturity

 

 

Pneumonia

 

 

Arthritis,

 

 

Emaciation

Actinobacillosis

 

Calf diphtheria

Caseous lymphadenitis

Atrophic

Anasarca

Tuberculosis

Arthritis

Enterotoxaemia

Rhinitis

Poorness

Blackleg

Ringworm

FMD

Swine Fever

External injuries

FMD

White Scour

 

Swine

Localized swellings

a)         tumours

b)         abscesses

c)         oedema

d)        haematoma

e)         hernia

Anthrax

 

Salmonellosis

 

Erysipelas

 

Inflammatory conditions of skin

a)   urticaria

b)   eczema

Rinderpest

 

 

 

Swine

 

Pregnancy

Mastitis

 

 

Tuberculosis

Fractures

Ringworm

Pneumonia

 

 

FMD

Dysnoea

Retained  placenta

 

 

 

Discharges from natural orifices

 

 

 

 

 

20.4.4 Judgment decisions at ante-mortem inspection

Post anti-mortem inspections, the animals can be subjected to any of the following three decisions.

·      Passed/Accepted/ Fit for slaughter: The animals free from any disease and normal can be directly sent for slaughter.

·      Rejected/ Condemned/ Unfit for slaughter: Animals suffering from fever (106oF or more), emaciated or dead animals, immature or pregnant animals are considered unfit and not passed for slaughter. Animals with established symptoms of diseases are not sent for slaughter.

·      Suspect: Animals falling under this category are those for which decision regarding fitness for slaughter cannot be made at the ante-mortem inspection stage. The following possibilities exist under these circumstances.

(a)   Slaughter under special precautions: Animals under suspect category if having symptoms of diseases.

(b)   Delayed/Detained slaughter: If the animals require treatment, or have history of recent treatment/vaccination, animals in febrile condition, fatigued and exited state may require treatment before they are slaughtered.

(c)   Segregated slaughter: Such decisions are made under special conditions such as dirty stock or animal suspected for some contagious diseases etc. Such animals are slaughtered at the end of the day’s kill or separately slaughtered and a thorough post- mortem examination is performed.

(d)   Casualty and emergency slaughter: Casualty slaughter is required when an animal is not in acute pain or immediate danger of death but affected with a more chronic condition like benign superficial tumors, obturator paralysis and post- partum paraplegia etc. When an animal is in acute pain or suffering from condition like, fractures, severe injuries, uterine prolapsed etc., where a delay in slaughter would be contrary to the animal welfare, then animals requires emergency slaughter. Prolonged recumbency in cows and sows after parturition, abscess formation in pigs due to Corynaebacterium pyogenes, pregnancy toxaemia and enterotoxaemia in sheep and injuries and affections of udder and uterus in cattle are the several other causes of emergency slaughter.

I.  “Fit” for slaughter.

II. “Unfit” for slaughter and the animal is condemned at ante-mortem.

III. “Suspect Animals” which fall under 2 categories

(a)       “slaughter under strict supervision”

(b)      “retain for a specified period” enabling +he symptoms to develop or subside and thereupon take a final decision on slaughter (fit/unfit/slaughter under strict supervision).