Effect of cereal type, disintegration method and pelleting on stomach content, weight and ulcers and performance in growing pigs

The purpose of this study was to investigate the effects of cereal type and feed processing on the prevalence of gastric lesions in pars oesophagea, stomach size, stomach content and firmness and performance in growing pigs. Data from 320 pigs were included in a 2 3 2 3 2 factorial experiment. The factors investigated were cereal type (barley or wheat), disintegration method (grinding or rolling) and feed form (pelleted or non-pelleted). Gastric lesions were investigated at slaughter and scored on a scale from 0 (normal) to 10 (very severe changes). The ground feed was produced on a hammer-mill, mounted with a 3-mm screen for barley and a 4.5-mm screen for wheat. Only 20% of the ground feed consisted of particles bigger than 1 mm in diameter, whereas it was approximately 50% of the rolled feed. Disintegration method and pelleting did not influence performance significantly and the differences between wheat and barley were due to the higher energy content in wheat rather than wheat per se. Wheat, ground feed and pellets reduced the empty stomach weight. Non-pelleted rolled feed increased both the firmness and dry matter percentage of the stomach content compared to ground feed. Rolled barley could be pelleted without a decrease in firmness of the stomach content as opposed to wheat. Pigs receiving rolled barley or wheat in non-pelleted form had nearly no gastric lesions (average score 5 0.7) as opposed to pigs receiving ground barley or wheat (average score 5 2.8). Rolled barley could be used as pellets without causing a high level of gastric lesions (average score 5 1.3), while rolled pelleted wheat caused a high level of gastric lesions (average score 5 4.3). The combination of ground wheat as pellets resulted in the highest score of gastric lesions (average score 5 4.9). A high firmness of the stomach content coincided with a low score of gastric lesions.  2000 Elsevier Science B.V. All rights reserved.