The present investigation aimed to study the ileal and total tract digestibility of 3 forages (clover–grass, clover–grass silage, and fi eld pea (Pisum sativum)–barley (Hordeum vulgare) silage) supplemented to a basal diet. A total of 24 pigs, adapted to eating forages by supplementing a basal feed with clover–grass silage from weaning, were fi tted with a T-cannula at the terminal ileum at approximate 30 kg BW. For each of the 3 types of forage, 2 balance trials with a 4 wk interval were carried out. Two pigs in each test were fed the basal diet and 6 others were fed the basal diet plus forage throughout the whole experiment. The intake of forages was low and quite variable and on average accounted for only 10 to 12% of the DMI. Ileal digestibility of protein estimated by collection from the T-cannula was higher (P = 0.031) than the digestibility estimated by the slaughter technique indicating some separation of the digesta collected from the T-cannula. The forages had, as expected, a lower total tract DM and energy digestibility than the basal diet (P < 0.05). The fresh clover–grass had a higher energy digestibility than the 2 silages (60 vs. 48%; P < 0.05). Inclusion of 10% of GE in the diet as forage reduced (P < 0.05) the energy digestibility of the ration by 2.2% for clover–grass, 3.4% for clover–grass silage, and 5.0% for pea– barley silage. In organic slaughter pig production, the overall energy supply from these forages is limited, but they may play an important role in satiety and rooting behavior.
Journal of Animal Science, 2012, Vol 90, Issue Supplement_4, p. 176-178