LPT 312: Abattoir Practices and Animal Products Technology (1+1)

REST AFTER TRANSPORT

Rest after transport is desirable as an animal slaughtered without an adequate period of rest shows a reduction in keeping quality of flesh due to

• Incomplete development of acidity in muscle,
• Early invasion of the system, by putrefactive bacteria from the intestinal tract.
• Stress and fatigue lower the quality of meat in several ruminant species due to depletion of glycogen in muscle. Due to low acid production, the ultimate pH of the muscle remains high causing a condition called dark cutting meat or dark, firm and dry (DFD) meat in cattle. Thus, the keeping quality of meat is reduced and it looks dark due to high water content. Such meat is unusually tender on cooking.
• In pigs, acute stress or excitement before slaughter causes another abnormal condition wherein low ultimate pH is achieved within 45 minutes due to rapid glycolysis even when the temperature of muscle is quite high. Such pale, soft and exudative (PSE) pork has higher drip and cooking losses.
• Animals fasting atleast 24 hours before slaughter has beneficial effect on carcass quality particularly in sheep.
• Animals, which are fasted bleed better, the carcass is easier to dress and has a brighter appearance than when animal are allowed to feed up to the time of slaughter.
• It is claimed that removal of hide is facilitated, if the animal has received plenty of water during fasting period.
• A period of atleast 12 hours detention and rest in lairage is therefore, essential before slaughter, except in the case of injured animals, which must slaughtered without delay.
• Animals are frequently detained in lairage for 2-3 days and during this period they should be subjected to routine ante-mortem examination.