Effect of dietary inclusion of whole ear corn silage on stomach development and gastric mucosa integrity of heavy pigs at slaughter

The effect of dietary inclusion of whole ear corn silage (WECS) on the stomach (S) development and on the incidence of gastric lesions was studied in heavy pigs. Three experimental diets were fed to groups of 14 barrows from 80 to 170 kg of BW : a control diet (C), based on cereal meals, soya bean meal and wheat bran and two diets containing WECS (15 or 30% DM, 15WECS and 30WECS, respectively) in partly or complete substitution of corn meal and wheat bran. Diets had similar fiber contents (NDF: 15.2-15.8 % DM), while differed in terms of average size of feed particles, because the forage was chopped at harvesting and not milled before administration to the pigs. The S of each pig was removed at slaughter, opened along the greater curvature and the content collected. The DM of S contents was higher in pigs fed 30WECS diets than the C diets (331 vs 233 g, P<0.05), with the 15WECS at an intermediate level (276 g). In addition pigs fed WECS diets showed a selective retention of more fibrous particles, as the NDF of S content (35-36% DM) resulted higher than that of C diets (23% DM). The dietary inclusion of silage caused (P<0.05) an increase in weight of the organ (0.38, 0.40 and 0.42 % BW, for diets C, 15WECS and 30WECS, respectively, P<0.05), while there were no difference among diets in the S internal surface. Moreover, the surface of the pyloric region, which represents the gastric area responsible for bolus retention, was higher (P<0.05) for pigs fed the 30WECS diet (20.4 % of total S surface) than 15WECS and C diets (21.8 an 20.4 %, respectively). The incidence of follicular gastritis was significantly lower (P<0.01) and the gastritis were less severe (P<0.05) for diets containing WECS than C diets. WECS diets influence the development of stomach and maintain the gastric mucosa integrity for a lower incidence of gastritis in heavy pigs.