Methods of flaying

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2. Contents Introduction Methods of flaying a) Large ruminant 1.Combined Horizontal & vertical method 2.Vertical method b) Small ruminant 1.Combined Horizontal & vertical method 2.Vertical method Advantages of combined horizontal & vertical method Disadvantages of combined horizontal & vertical method Advantages of vertical method Disadvantages of vertical method Definitions

3. Introduction: Stunning of the animal is done by mechanical, electrical or chemical method followed by sticking/bleeding of the animal and then flaying/ skining is done. Flaying is defined as removal of a skin/hide from a carcass of slaughtered or dead animal . Hide is one of the precious product obtained from the slaughter of animal used for the preparation of leather goods. Price of hide depends upon the quality of hide. To obtain quality product specific scientific methods are proposed to avoid unnecessary cuts in hide which reduces the quality of hide.

4. Methods of flaying Combined Horizontal & vertical method 2. Vertical method Flaying/skinning should be done within a few hours of the animal's death as the skin will peel off especially easily. Make sure the knives used are sharp.

5. Combined horizontal & vertical methods Head: After bleeding, while the animal is still hanging from the shackling chain, the horns are removed and the head is skinned. The head is detached by cutting through the neck muscles and the occipital joint. Hang the head on a hook.

6. Legs . Remove skin and the legs at the carpal (foreleg) and tarsal (hind leg) joints. The forelegs should not be skinned or removed before the carcass is lowered on to the dressing cradle or the cut surfaces will be contaminated. The hooves may be left attached to the hide. Fig. Correct line of cutting for hide removal

7. Clear the skin carefully from around the vent (anus) avoiding puncturing it and cut the abdominal wall carefully around the rectum. Skin the tail avoiding contamination of the skinned surface with the hide. Raise the carcass free of the floor and finish flaying.

8. Vertical methods High-throughput plants have overhead rails which convey the carcass from the sticking point to the chills. Hide removal is carried out on the hanging carcass. The operations are as in the combined horizontal/vertical method, but as it is not possible to reach the hide from ground level more than one operator is needed. A single operator may work with a hydraulic platform which is raised and lowered as required . Fig. Pneumatically operated rotating knives (flayers) speed the removal of the hide from the flanks

9. Automatic hide pullers are used in high-throughput slaughterhouses. Some types pull the hide down from the hind, others from the shoulders upwards toward the rump. Automation of hide removal reduces contamination since there is less handling of the carcass and less use of knives. Moving overhead rails also improve hygiene by reducing carcass contact with operators, equipment such as dressing cradles and with each other since carcasses are evenly spaced. Fig. Flaying knives are used for the more intricate parts of hide removal

10. FLAYING/SKINNING GOAT/SHEEP Ripping is the process of tearing the skin to start the skinning process. Steps in the ripping: One long and straight incision from the jaw to the anus along the center line of the belly. Four circular cuts around the shanks at the level of the knee and hock joint. Two cuts on the inside of the forelegs, knees to the breast bone. Two cuts on the back of each hock joint to a point mid-way between the anus and scrotum.

11. Combined horizontal/vertical method The animal is turned on its back and cuts are made from the knuckles down the forelegs. The neck, cheeks and shoulders are skinned. The throat is opened up and the gullet (food-pipe) is tied off. The skin on the hind legs is cut from the knuckles down to the tail root. The legs are skinned and the goat/sheep is hoisted by a gambrel inserted into the Achilles tendons. The pelt is then pulled down over the backbone to the head.

12. Moving cratch and rail system. The hanging carcass is lowered on to a horizontal conveyor made up of a series of horizontal steel plates, bowed slightly and divided into sets large enough to cradle a single animal. Two operators usually work together on each lamb performing the legging operations and opening the skin to the stage where it can be pulled off the back. When the gambrel is inserted into the hind legs it is hoisted on to a dressing rail.

13. Vertical Method Flaying/ skinning of sheep and goats can be started by making a small incision on the inside of one of the hind legs. The hind legs, including a small portion of the skin covering the abdomen and edges of the butt round the rump, can be flayed with a knife and fist while on the floor. The carcass should then be hoisted.

14. Cont….. To hang a sheep/goat by its back legs, find the large tendon that connects the lowest leg segment with the rest of the leg. Poke a hole in between that tendon and the leg bone at hock joint. Use your fingers to feel the lump that is created by the double jointed bone. Then sever the lower leg at the lower of the two joints. Cut skin and tendons around the joint, and then snap it over leg.

15. CONT….. Skinning is a straight forward activity if one follows the body's built in guidelines because the skin and muscle tissue are naturally separated from one another by protective membranes. The skin easily separates from the meat along these membranes when you pull it. After getting a clean start, there is little risk of tearing the skin or the meat. Sometimes, the belly skin is removed using a knife leaving the surface of the carcass with close serrated scores.

16. Cont…. When we use a knife to slice the skin from the animal we inevitably violate these layers and make the whole job harder. Once you cut into the meat, we are no longer working with the natural division between meat and skin. We usually end up removing large chunks of meat, as well as putting cuts and holes in the skin. These cuts (also called scores) and holes open up and enlarge easily, increasing the amount of work at every stage of the tanning process later on.

17. Fisting process 1. 2. 3. 4.

18. The butcher must take care to frequently wash his hands and arms and not touch the dirty outside of the animal’s skin while removing the skin this way. An alternative to fisting is the use of compressed air. If facilities are available, a compressed air pipe is introduced between the skin and carcass surface and the air pressure gradually detaches the skin. The air must pass through a filter in order to reduce the micro-organisms present in the air, which otherwise can constitute a source of contamination. Blowing air into the cut in the hind leg is a traditional practice in many areas when the skin, usually goat skin, is required as a water bag

19. A knife should not be used in the final phase. The flayer uses his weight with downward pressure to remove the skin especially from the tail area, the neck and forelegs. After the skin is separated, remove any meat and/or fat from the skin. Wash flesh side if contaminated with blood and/or gut contents. Then immediately cure with common salt or by air drying to prevent putrefaction. Removal of fat and flesh Salting Frame drying

20. Advantages of Combined horizontal & vertical method 1. Less chance of contamination of meat with skin during flaying. 2. Less mechanisation required as during finishing of flaying animal is brought in horizontal position. 3. More efficient, less time consuming, less labour required. Disadvantages of combined horizontal & vertical method As it is combination of both the position horizontal and vertical carcass is interchanged as and when required hence have no practical disadvantage. It is more complicated to practice .

21. Advantages of vertical method: Hoisting the animal makes it easy to use one’s body weight to pull the skin off. It also assures that the meat will stay clean. The slaughtered animal can either be hanging from the neck or from the legs. Knifing is not required, fisting is sufficient and better option to avoid scores. Fisting is hygienically critical.

22. Disadvantages of vertical method: It is not possible to reach the hide from ground level more than one operator is needed. A single operator may work with a hydraulic platform which is raised and lowered as required. Automatic hide pullers, dressing cradles and more mechanization required.

23. DEFINITIONS: Curing: The treatment of skins with common salt or by air drying to prevent putrefaction. Defatting : The removal of unwanted fatty (adipose) tissue from the flesh side of a fresh skin during fleshing. Flay cuts: Damage caused by careless use of a knife during flaying, sometimes cutting through the skin. Flaying (skinning): The removal of a skin from a carcass. Flaying knife: The knife used to sever the subcutaneous tissues when removing the skin from the carcass. Flesh side: The inner side of a skin next to the body of an animal in life.

24. Fleshing: The removal of the residual connective and adipose tissues from the flesh side of a skin after flaying. Gouges: Knife damage to the skin during flaying, taking out scooped portions of the corium. Grain layer: The top portion of the dermis. Pattern: The pattern of skin when laid out flat. Putrefaction: Bacterial and enzymatic breakdown, rotting. Scores: Knife damage to skins during flaying by cuts that do not fully penetrate through the skin. Trimming: Removal of unwanted portion of a skin.