Treatment procedures for stable waste and reduction or elimination of infective eggs and larvae of the genus Strongylus spp.

Keila Youko Fujii João Ricardo Dittrich Edilene Alcântara de Castro Emanuel Orestes da Silveira About the authors

The objective of this study was to characterize the processes of composting stable waste and to evaluate the efficiency in the reduction or elimination of infective eggs and larvae of Strongylus spp. The composting treatments were: open, without rotation, in a smaller volume (CASRm) and larger volume (CASRM); open, with rotation, in a smaller volume (CAm) and a larger volume (CAM), and anaerobic in biodigester (CF), in three replicates. The monitored parameters were temperature, moisture and presence of parasites in the beginning and at the end of the experimental period. Temperature at the center of CAM and CASRM reached ita peak on the first day, of approximately 60ºC, being higher than 50ºC only in the first three days. In the other treatments, the maximum temperature was around 30ºC. Before treatments were applied, it was possible to observe high levels of contamination by larvae of Strongylus spp. (with 25.3 larvae per gram). The reduction of infective third stage larvae in the compost at the end of the experiment was of 97% (CAM), 87% (CAm), 90% (CASRM), 100% (CF), and 26% for the CASRm treatment. On the outside it was not possible to detect the presence of the parasite. The humidity outside the compound at the end of the experiment was of approximately 17 to 30%, and internally, of 40 to 60%. Helminth eggs remained viable even after the composting process and heaingt treatment. The results indicate that the mere provision of stable waste without the proper handling and in small volumes does not lead to the total elimination of eggs and infective larvae of Strongylus spp.

composting; infective larvae; temperature

Instituto Biológico Av. Conselheiro Rodrigues Alves, 1252 - Vila Mariana - São Paulo - SP, 04014-002 - São Paulo - SP - Brazil