Lopes Dias Juffo, EE; Matos, LM; Vieira, TR; Leal Ribeiro, AM; Schmidt, V; ,
Background: Finding alternative foods that the meet nutritional and energetic requirements of pigs, with less costs and without affecting negatively the performance of the animals, is a must in order to achieve a better production efficiency and to maintain the market prices. In Porto Alegre, RS, Brazil there is a group of pig farmers that is part of a city hall's project, in which organic solid waste (OSW) is reused in pig feeding. This waste is composed of leftovers from the prepreparation of food and of unused food from units preparing and serving food (USA). This study aimed at evaluating the nutritional composition of this waste for utilization in pig feeding, as well as its microbiological aspects.Materials, Methods & Results: Organic solid waste generated in 14 units of a "self service" food store from a shopping mall were sampled. The samples were homogenized in each collection, resulting in four compound samples. Dry matter (MS), ashes (CZ), crude fat (GB), crude fiber (FB), crude protein (PB), calcium (Ca), phosphorus (P), organic matter (MO), nitrogen-free extract (ENN), total digestive nutrients (NDT), digestible energy (ED), metabolizable energy (EM) contents and pH were determined. In order to analyze the data, Descriptive Statistics was used and the values were compared with those found in Brazilian tables for poultry and pigs. We verified average contents of 78.76% moisture; 3.97% PB; 0.52% FB; 4.2% EE; 13.21% ENN: 0.18% Ca; 0.15% P, 924 kcal/kg ED and 756 Kcal/kg EM. It was calculated that 10 kg.animal(-1) OSW is necessary for the grow phase (30 to 70 kg of live weight). In the finish stage, this supply must be significantly increased, with a daily OSW value of 13 kg.animal(-1) (70 -100 kg) to 15 kg.animal(-1) being calculated. The microbiological analysis consisted of qualitative search for Salmonella sp. and quantification of total and thermotolerant coliforms. We observed absence of salmonellae and variability in the thermotolerant coliform count, (6 x 10(2) to 1.3 x 10(8) ufc.g(-1)), with no confirmation of Escherichia coli.Discussion: About 90% of animal feed formulations used a mix of maize and soybean meal, which demonstrates the high demand for these cereals in Brazil. Approximately 70% of nutrient consumption is observed during the growing and finishing phases; several researches have been made in a bid to find alternative foods, as a replacement to maize and soybean. Some of these include barley, wheat bran, rice bran, achiote seeds, pasta leftovers, almond and cashew nut meal, cheese brine, cottonseed meal, citric extracts, etc. The analysis of the average nutritional composition of the OSW used in this study reveals high moisture content and, consequently, low PB, FB, ENN and energy contents. With regard to the ash contents (mineral matter), their values were the same found in reference foods, with Ca and P having an adequate ratio. It is clear that when using OSW, it is important to perform adjustments of the daily amounts supplied. The utilization, supply and sanitary management of this diet deserves attention, due to its high water volume. On the microbiological point of view, the absence of salmonellae in such residues become important, since the presence of these microorganisms in pork meat is a food safety issue. Since OSW are mostly composed of products of plant origin, it is normal to observe a high thermotolerant coliform count. Even without the confirmation of Escherichia coli, it is necessary to observe the standards and legislation in force that advocate the thermal treatment of this kind of material used in animal feed.