In this study, organically raised pigs received an increasing proportion of grass silage up to 10 and 20% dry
matter in the daily ration in the grower and finisher period, respectively, to determine the effects of grass
silage on feed intake and growth performance. The pigs receiving a mixture of grass silage and compound
feed ingested 0.3 kg DM/d (13% of their daily ration) as grass silage and realised a similar daily net energy
intake as pigs fed compound feed only. However, the silage fed pigs realised a lower daily gain (37 g/d) and
a lower calculated net energy utilisation (1.6 MJ/kg) for gain and a lower dressing percentage (1.1%) of the
carcass. The optimal feeding system and the nutritive value of grass silage for growing pigs requires further
investigation to improve the silage intake and clarify and minimise the loss in animal performance.