Boiled full inflorescences (BB) and Raw stems (RB) of broccoli (Brassica oleracea var. Italica), as industrial by-products, were ensiled in laboratory-scale silos and were sampled at different times. To evaluate its suitability as feed, the fermentative, chemical and different pesticide parameters were determined. The environmental pollution effect and the volume of released effluent were determined too and the effluent prediction equation was estimated. Both by-products presented high moisture content initial (73.2 and 103.9 g kg-1 DM in RB and BB, respectively) and they produced a very high effluent volume, BB released 78.97 and RB 285.65 mL kg-1, respectively. The best equation to predict the effluent production was the reciprocal model (r2= 0.920) from where can be seen that small increases on moisture content can produce very important elevations on effluent production. Both silages showed that effluent had strong potential pollution (22.97 and 39.06 gO2 L-1 of BOD, respectively). Levels of different pesticides were not found in BB or RB silages. The by-products showed that can be effectively ensiled under laboratory conditions.© 2014 Friends Science Publishers