Pork export in Brazil represents 625 thousand tons/year (ABIPECS, 2005) and it is an important item in the county's agribusiness. Lately Brazilian swine production has been strongly impacted by the new consumer market demand regarding welfare norms and standards. The analysis of animal vocalization allows the interpretation of welfare pattern in a non-invasive way, and it may be used for both identify the animal and to assess welfare issue as well as health status and social adaptation. This paper exposes partial results of a project with the objective to develop an expert system to register and analyze distinct sounds emitted by swine in different growing stages correlating it with levels of stress, for assessment and controlling decision making process. The software was developed sing Delphi5. Through the component Uwaveln the PC hardware registered the signal converting them into bytes. Using Fourier Tranform it was possible to describe the sound spectrum and transform it into frequency and intensity. Validation of the software was done in a commercial swine farm using animal from growing phase. Results showed that it was possible to make decision as far as environmental control is concerned, based on the sound level recorded.572576Hopp, S.L., Owren, M.J., Evans, C.S., (1997) Animal Acoustic Communication: Sound Analysis and Research Methods, , Springer, HeidelbergJAHNS, G. Understanding Animal Vocalization. Disponível [on line] em http://www.tb.fal.de/staff/jahns/animal.htm. Data de acesso em 28/04/2004Manteuffel, G.Puppe, B. and P. C. Schön. 2004. Vocalization of farm animals as a measure of welfare. Applied Animal Behaviour Science 88.163-182Marx, G., Horn, T., Thielebein, J., Knubel, B., Von Borell, E., Analysis of pain-related to vocalization in young pigs (2003) Journal of Sound and Vibration, 266, pp. 687-698Muñoz, L.A., (2004) Algunas consideraciones sobre los conceptos de bienestar en la especie porcina, pp. 20-10. , http://www.portalveterinaria.com, on line] Disponível no site, Acesso emOwren, M.J. and R.H. Bernacki. 1997. Applying linear predictive coding (LPC) to frequency-spectrum analysis of animal acoustic signals. In: Hopp S.L., Owren M.J. and C.S. Evans. (Eds.), Animal Acoustic Communication:Sound Analysis and Research Methods. Springer, Heidelberg, pp. 129-162Puppe, B., Schon, P.C., Tuchscherer, A., Manteuffel, G., Castration-induced vocalization in domestic piglets, Sus scrofa: Complex and specific alterations of the vocal quality (2005) Applied Animal Behaviour Science, 95, pp. 67-78(2006) Livestock and Poultry: World Markets and Trade, , USDA, MarchWeary, D.M., Fraser, D., Vocal response of piglets to weaning: Effect of piglet age (1997) Applied Animal Behaviour Science, 54, pp. 153-16
