ABSTRACT This study aimed to evaluate the efficiency of anaerobic digestion and biogas production by manure from pig supplemented with ractopamine over different periods. We used manure of 50 finishing pigs according to the following diets: without supplementation and supplemented with 20-ppm ractopamine during 7, 14, 21, 28 and 35 days pre-slaughter. Continuous bench biodigesters were used in the experiment. We measured biogas production and made analyses of total (TS) and volatile solids (VS), pH, total phosphorus (total P), total nitrogen (total N) and ammoniacal nitrogen (ammoniacal N) in samples of manure, affluent and effluent from biodigesters. The pH and ammoniacal N as indicator parameters of the process balance and stability were satisfactory.... |