Abstract:
The production of poultry meat at abattoirs implies a tremendous amount of organic matter that requires environmentally and biologically safe disposal or utilisation. As a result, waste management is a concern in poultry abattoirs worldwide. Problems with proper storage, handling, management and utilisation of by-products have come to the forefront in planning, establishing and operating of poultry abattoirs.
The rationale for this study centres on the need for the review of poultry abattoir waste management practices, by-product production and environmental implication at South African high-throughput abattoirs. The need for this review stems from the rapid growth of the poultry industry over the past ten years. The industry has responded to this growing demand with larger and faster processing lines and more employees. This has led to the generation of high loads of waste material associated with negative environmental impacts. Poultry waste is of great concern as it plays a major role in environmental affairs over and above the present crisis with waste in South Africa, especially in rural and peri-urban areas.
The primary objectives of the study were to identify the existing waste management practices in relation to the sources, type of waste material generated, and the methods of handling (collection, storage and disposal) as well as to ascertain whether there is any in-house treatment methods practised. In addition, to identify any environmental impacts resulting from waste management practices.
To obtain data, site visits were conducted countrywide and abattoir personnel were interviewed through a questionnaire, in detail about the operation and waste management practices of their respective abattoirs. Their experiences in the industry regarding waste management were determined as well. From a total of thirty-four registered and operating high-throughput poultry abattoirs, twenty-six (76.4%) were visited.
Huge amounts of wastes are generated at South Africa high-throughput poultry abattoirs, and these amongst others includes blood, feathers, feet, intestines, trimmed meat off-cuts, faecal matter, condemned chickens and waste-water. Waste handling practices varies according to abattoir preferences. Different collection facilities are used for different types of waste, 50 - 750_ containers and blood troughs are used for blood (table 4.5), crates, wheelie bins, conveyors, black rubbish bags for feathers (table 4.6).
Waste is either stored at the dirty area of the abattoir or in an open space next to the abattoir under strict supervision prior to disposal or by-product processing. Since not all abattoirs dispose off generated waste, some abattoirs have by-products processing facilities either on site or outside abattoir premises. Examples of by-products produced (table 4.3) include poultry (carcass) meal, feather meal, poultry oil and blood meal. Disposal methods used differs from burial, rendering, land application, municipal landfill, collection by farmers (animal feeding), burning, composting depending on waste type. It should however be noted that some of disposal method used are not legally approved in South Africa although legally permitted in other international countries as per literature review.
Three environmental implications were identified by the respondents included in the study (table 4.14) and these included air pollution, water pollution and land/soil pollution.
Recommendations are made to encourage the safe disposal of abattoir waste, minimisation of environmental implications and to limit the methods of disposal to those that are internationally permitted and suggested.