Exsanguination:The Effects On

Carcass Quality

Exsanguination

• The drainage of blood is called Exsanguination

• Slit throat of animals causes quick Exsanguination

• Cut carotid artery ensures that brain gets no blood

• Cut jugular artery quickly drains the brain

• Brain quickly looses functionality due to ischemia

• Complete drainage occurs in about two minutes

• By the end of the process 30-50% blood remains in the body

• Deteriorates faster than meat• Congests in the vesicles

• Blood starts deteriorating inside the body

• can provide medium for a local infection to spread generally

• Can have pathogens, microbes and parasites

• Causes red carcass decreasing shelf life and palatability

• Contains hormones

• Cytokines that stimulate functioning of cells

• Stress hormones that are released during restraining and sticking

• Cortisol and histamine that cause plasma to leak into tissue

causing edema due to capillary dilation.

Blood

BloodIfRetained

• Bacterial growth occurs quickly after slaughter

• Meat has blood color and bad metallic smell

• Meat color changes over time From red to blue and then black

• Gory and unsightly carcass

• Any microbe present anywhere in the body generalizes

• Blood contains buffers

• The pH of meat cannot drop, required acidity cannot

be achieved hence reducing the meat shelf life

• microbes growth is retarded at low pH which cannot happen if blood

is retained

• Blood also harbors antigens and some humans can potentially be allergic

• Hemoglobin degradation increase oxidation causing excessive and quick

rancidity

Stunning

• Animals can be stunned prior to bleeding but evidence suggests

That it does not affect the bleeding in any way

• The bleeding rate and carcass clearance remains unaffected

• Stunning is done by traumatizing the brain

• concussion

• Free bullet

• Sinusoidal electric shock

• It is meant to make the slaughter more humane but experiments

show that the execution of this process is indifferent for the animal

Bleeding:The Right Way

Stick sharpest of knives only:

• About 15cm plain knife

• Single stroke

• Incise the arteries

• No rough edges on the arteries

• Smooth free ends of vesicles

• No premature coagulation

• Blood flows steadily

• Thorax should be avoided from incising or chest will fill with blood

• The most hygienic system of bleeding and dressing:

• Shackle the animal immediately after stunning and

then hoist it on to a moving rail

• The animal is stuck while being hoisted to minimize

the delay after stunning Bleeding continues until the

blood flow is negligible

• carcass dressing should begin without further delay

• Gullet of the knife collects Blood for human use to

avoid contamination from the wound

• The knife may be connected to a hose to reduce the

risk of contamination. The hose may even be

connected to a pump to speed the blood flow

• Between 40 and 60 percent of the total blood

volume will be removed though this will be reduced if

sticking is delayed.

• To prevent coagulation, citric acid solution made up

with one part citric acid to two parts water is added

at a rate up to 0.2 percent of the blood volume.

• If esophagus is pierced semi-digested food may be

regurgitated contaminating the blood and neck

wound.

Bleeding on a rail

• Horizontal bleeding is claimed to give faster

bleeding rates and a greater recovery of blood

• This may be due to certain organs and blood vessels

being put under pressure when animals are hoisted

thus trapping blood and restricting the flow

• Bleeding on the floor is very unhygienic

• The operation should take place on a specially

designed, easily cleaned stainless-steel table which

should be cleaned frequently

• If blood is to be saved it must not come in contact

with the table before reaching the collecting vessel.

Horizontal bleeding

Ritualistic bleeding

Dabeehah and Sechitha• Closely related to each other

• Require no stunning but need great skill

• Produce Hilal And Kosher Meat

• Only Muslim or Jew allowed to carry out procedure

• Centered around welfare and minimal

pain while achieving maximum purity

by removing maximum blood

• Properly done; the meat from both processes

is perfectly healthy for human consumption

Delayed Bleeding

• Dressing percentage, chilled carcass weight and the pH are not

affected by delayed bleeding

• The volume of blood drained decreases as the period between

stunning and bleeding increases

• The drip loss and cooking loss increases as the time between stunning

and bleeding increase while the Water Holding Capacity (WHC)

decreases

• The effect of delayed bleeding on shear force, WHC, drip loss and

cooking loss became more pronounced with ageing

• Apart from the color and juiciness rating that significantly decreases,

the other eating qualities are not affected by delayed bleeding.

Improper Bleeding

• The neurological, cardiological and muscular effects of stunning can

impede Blood loss though there is no significant difference

• Exudation occurs more in case of meat that is improperly bled

• Exudation occurs more in case of meat of animal that was stunned

before sticking

• Even more so in case of electrically stunned animals

• Cooking loss of >22% is seen in improperly bled animals while kosher and

halal meat show <18% cooking loss

• About 20% trachea fills with blood when animals are stunned while

<10% in case of kosher and Hilal

• Alveolar capillary network ruptures when lungs cannot drain

immediately

• Carcasses of male animals decompose faster if improperly bled than

those of female carcasses; also in the case of stunned vs. Hilal and

Kosher

• Male carcasses are generally redder than female ones

• Even less amounts of retained blood imparts more color as the

blood is denser in all aspects

• Improperly bled carcasses cause slower pH drop as the blood acts as

buffer though glycolysis occurs at similar rate

Carcass QualityResidual Blood

&

The results of excessive bleeding caused by different stunning techniques and

by imperfect slaughter increase the hemoglobin concentration in the muscle

and decrease the organoleptic quality. The increase in red and yellow color

causes the pink coloration which is due to the imperfectly bleeding and which

may lead to a downgrading of the carcasses. Samples from imperfectly bled

carcasses also show a high value of Lightness(54.09) which produce a pale

color. Residual blood is among the key factors affecting the quality of the meat

color. Bruises, hemorrhages, and poor exsanguination efficiency can

negatively affect color of the meat and skin; these are major quality defects

and are associated with undesirable discoloration and reduced shelf life

Colorimetric Analysis

Carcass QualityResidual Blood

&

variability of pH standards for meat chickens are be-tween 5.7 to 6.20. Normal

values of ultimate pH ranged from 5.7 as minimum normal value and 6.25 as

maximum normal value, outside this range, and lower values to 5.7 meats

have defects and are called

• PSE (pale, soft, exudative)

For higher values to 6.25 meats have defects and are called

• DFD (dark, firm and dry) .

At 7°C storage temperature, the average pH of perfectly bled meat is (6.07)

which was significantly lower than the average pH of imperfectly bled one

(6.27).

A rise in the storage temperature increases the pH but the pH of the perfectly

bled meat is still minimal. There is a strong relationship between carcass

residual blood and the growth of the degree of pH, but also indicates the

season effect. The lowest level of pH is recorded during the winter. After this

period the values increase to reach the highest rate in the summer, especially

at 7°C storage.

pH

Dabeehah and Sechitha seem

to be the best methods of

slaughter. Good and skillful

practices in hygienic conditions

without stunning and with

proper Exsanguination ensure

no residual blood in meat and

optimal meat properties for

human consumption.

Evidently

Improperly BledpH of 6.9-7.2

Color Dark red

Taste Metallic or other (fungi, bacterial

or drugs)

Pungent, sour smell depends on type of

growth.

Degraded even in proper storage.

Shelf life decreased Properly BledpH of 6.0-6.9

Color pale red

Taste Meaty

No smell

No growths

Able to survive a few weeks in proper

storage.

Shelf life increased

Overview