Slaughter premises normally seen in developing countries are of three kinds: modern abattoirs, old slaughterhouses and slaughterslabs and makeshift premises.
Of the three, modern abattoirs represent the most progressive and the ideal in conventional abattoir design, equipping and services. Often built and controlled by central governments with foreign technical assistance and management, these abattoirs are operated on industrial lines with a wide range of services featuring cold storage, processing, by product utilization and waste recycling activities. Some of them have export objectives primarily in chilled and frozen meat although at times some of their manufactured products (and byproducts) are channelled into local sale in substitution for imports. Few modern abattoirs in developing countries slaughter directly for public consumption, being as they are commercial or profit-motivated establishments with little inclination for low revenue services.
The old slaughterhouses and slaughterslabs handle the bulk of public slaughters. These premises merely make facilities available for use by licensed butchers and traders for the slaughter of livestock at stipulated fees, and in accordance with public health, inspection and marketing regulations. Slaughterhouses and slaughterslabs thus operate as service establishments under the management of municipal and local authorities, their field of activities often being limited to the larger towns and built-up areas.
The third category of slaughter premises, the makeshift, for want of a better term, include all kinds of places such as converted buildings or rooms, shade of trees as well as open baregrounds that a butcher or a community may find convenient for the operation.
Mostly private-owned and under no formal authority or licensing, these premises and their products are neither inspected, quantified nor subjected to trade and health regulations.
Makeshift slaughter premises are characteristic of village and rural locations. Occasionally, however, they may occur in the suburbs or on the fringes of larger towns. In the latter, they are sometimes considered to have links with illegal livestock trading and the slaughter of sick and diseased animals. Because they defy obvious norms in slaughterhouse construction, equipment services and hygiene, their existence and operation is not advised. In unavoidable cases, these premises should be allowed to operate only if the animals and their products are to be inspected.
This part of the Manual will be concerned with slaughterhouses and slaughterslabs of the kind found in larger towns and built-up areas as these constitute the core of official slaughter operations in the developing countries. Indeed, many of the present premises are fairly old structures, having been built several years ago (some more than half a century old), and at a time municipal engineering and public health requirements were less stringent and different from those prevailing now. The subject of siting, layout and construction are dealt with in this chapter, followed in the next (Chapter 3) with facilities for slaughter, equipment and operating tools. Also taken into consideration are the key requirements for slaughterhouse rehabilitation and modernization.
Slaughterhouses are best sited on the outskirts of a town or village, at a distance from built-up areas. This is to prevent possible inconvenience to dwelling-places either by way of pollution from slaughter wastes or by way of nuisance from noise, stench or the presence of scavenging animals such as vultures, stray dogs, etc.
Conversely, remote location secures the premises from contact and likely contamination from residential units close by. Nevertheless, some proximity to the city or town should be maintained to take advantage of vital services such as power and water supplies.
Another feature of the area selected is that it must be open, treeless and with air currents to provide for natural lighting and ventilation as dark environments can cause lapses in hygiene while stagnant air can induce growth of spoilage organisms on meat and meat handling equipment. Trees also attract birds which are agents of contamination.
The siting of slaughter premises near waterlogged areas must be avoided. Evidently such sites can raise sanitation problems as in the breeding of mosquitoes and stagnation of wastes. Where possible, the location of the plant should be made at a higher elevation relative to the surroundings (Fig. 1).
Location near watercourses or inland bodies of water such as rivers, lakes and lagoons is also unadvisable. This is to avoid the temptation of discharging wastes into the waters with consequent pollution and cross-contamination of the premises. Liquid waste can, however, be discharged into these waters provided it is treated and rendered safe for aquatic life or for humans using the waters.
Discharge of waste into the sea without prior treatment is recommended provided the effluent is delivered through pipes and deposited far out into the sea, at least 5 km from the coast. However, this should be done in line with local municipal and environmental regulations where these exist.
The choice of a site for construction must be followed by considerations for layout. Here both the premises and the immediate environment need consideration. Premises meant to serve large communities and hence likely to have a heavier workload must be planned as full slaughterhouses and not as simple slaughterslabs. This means that they must have physically identifiable operational zones such as killing, dressing, inspection and off-cleaning areas, each in turn provided with its given set of equipment and operating gear.
FIG. 1 LOCATION OF SLAUGHTER PREMISES AND AUXILIARY UNITS
The premises must be fenced to keep out undesirable individuals and to prevent animals from entering the yard. Outside the fence, a kraal with roofing must be provided, but within the yard and close to the killing floor, a lairage would be necessary. Lairages are enclosed or roofed spaces for resting animals prior to slaughter, while kraals are essentially holding grounds for animals waiting longer for slaughter. Both must be provided with watering facilities. In addition, the kraals should have feeding troughs for cut herbage, or else the animals should have ready access to grazing in the neighbourhood.
Auxiliary services and functions such as livestock marketing, hide-drying and manure accumulation and collection must be located at some distance from the plant. In other words, no activities should take place in the immediate environs of the premises other than the resting of animals and, if unavoidable, kraaling. Slaughtering in the yard in rural slaughterslabs during peak seasons must similarly be discouraged, as all such activities predispose meat to contamination.
The general principle regarding the choice of materials for constructing and equipping slaughter premises is that the materials must be durable and be able to resist deterioration or destruction from external influences such as the weather, air, steam, water and insects. This means that materials such as swish, wood, thatch and corrugated iron are undesirable. In their place brick, sandcrete, stone, reinforced concrete, asbestos, tile and slate should be used.
For the operating chambers, the materials used must not be pervious to water and blood or stained by fat; glazed tile or a hard smooth material should be used for the walls to facilitate cleaning and prevent absorption of moisture and fat. A similar principle should apply to the selection of equipment for the chambers: stainless steel, galvanized metal and aluminium are good choices for metal fittings or furnishings while plastics may suit containers and working surfaces. The general items of furnishings are discussed in the next chapter.