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

METHODS OF DRESSING

I. Line or On-the-rail Dressing

• This type of dressing is adopted in the American Continent, which was originally emanated from Canada. This method consists of conveying the carcass by gravity or power through an overhead rail to various places after stunning and sticking. The process of dressing is divided up into various stages. Men will be standing at various places and carcass will reach them and they will attend to their allotted work. In this system manual labor saving devices such as brisket saw, hock cutter, hide puller, aitchbone cutter, etc., are used in the dressing process. This helps in complete dressing at a higher rate of slaughter. Besides reducing the labour load, this arrangement also makes for better job satisfaction. In modern meat plants, which may be as high as 5,000 cattle, 10,000 sheep and 3,500 pigs every 10 hours the line method of slaughter is highly essential to reach the high production.
• Several systems of line dressing are in operation, the type depending mainly on the level of throughput, equipment design and species, being most complicated in cattle. Constant research is undertaken with a view to effecting more efficient methods of line dressing.
• A line system of slaughter with a rate of 60-75 cattle/h needs approximately nine meat inspectors and one veterinarian for initial and final inspection. Correspondingly smaller numbers are necessary for pigs and sheep inspection. Adequate space and facilities for inspection must always be provided. Indeed all-too-common tendency to over-save on space when installing line slaughter systems must be resisted.

In this line system there are four types.

• Gravity rail system
  • In this method, carcass will be suspended from a spreader and single-wheel trolley or runner, gravitated to each station and stopped by a manually-operated stop on the overhead rail.
  • The system is used for lower slaughter rates of 10 to 40 cattle/h. Among the systems this is probably the most compact and economical. Here generally no mechanical means are used. Since the design is the simplest there isles chance of serious breakdowns with consequent loss of production. Various items of equipment may be used with the gravity rail, e.g. a moving-top viscera inspection table or a paunch truck, but, because throughput is small, a mechanical hide-puller is rarely used. Adequate ceiling height is necessary because of the pitch of the rail to gravitate the carcass.
• Intermittent powered system 
  • In this system carcass is suspended on a spreader (gambrel) and trolley, and moved mechanically on a level rails at intervals by means of variable timing device which can be pre-set to suit the slaughter rate. Here slaughter rate is 10-75 cattle/h.
• Continuous power system
  • In this system the dressing line will be in continuous motion. More sophisticated instruments are used in the slaughter line (mechanical hide puller moving top inspection table, etc.). In this system carcass can be revolved to a full 360⁰. So, while on the rail allowing the operator can work on all sides from one place.
  • The work platform may be fixed or movable, elevated or lowered, which enables the operator to work easily. Rate of slaughter will be about 40-120 animals/h.
• Canpak system
  • This is a continuous conveyorised method in which heavy beef trolleys or runners suspend the carcasses from the overhead rail; no gambrels or spreaders are used as in other methods. Here everything is done systematically and most of the work is done by mechanical means. Rate of slaughter is 50-150 animals/h.
  • It is probably the most common form of line system now used in large modern meat plants. In this system from the time of arrival of animals till it is completely dressed the work is divided into 32 divisions. Each work carried out by one man specifically stationed at one place along the moving rail system. When the carcass reaches to his place he will attend to only his allotted work.
  • So in this system for one labour operative force will be not less than 32 persons. This system is developed and patented by the Canada Packers Ltd., Canada; hence it is called Canpak system.

II. Booth System

• In this system one man does all work in one place. No individual allotment of work. If a worker starts sticking cattle and he will finish all the operations of dressing completely and then he will go for the next animal.