Effect of particle size distribution and dietary crude fibre content on growth performance and gastric mucosa integrity of growing-finishing pigs

This study was designed to examine the effect of crude fibre (CF) content and particle size of the diet on growth performance, carcass yield and gastric mucosa integrity. The experimental design was a 2×2 factorial trial with 192 pigs fed from 24 to 110 kg bodyweight. Four diets were compared: (1) low fibre finely ground; (2) low fibre coarsely ground; (3) high fibre finely ground; and (4) high fibre coarsely ground. All ingredients were ground before mixing. The high fibre coarsely ground diet resulted in the fewest lesions in the gastric pars oesophagea (P<0.001). Coarse grinding also resulted in the lowest urease activity in the stomach (P=0.006). The feed conversion ratio was worse on the coarsely ground diet than on the finely ground diet (P=0.038), whereas carcass yield was lower for pigs on the high fibre diet vs. the low fibre diet (P<0.001). Coarse grinding feed ingredients in a growing pig diet that is high in CF may reduce macroscopic lesions of the pars oesophagea but such a diet was accompanied in this study by inferior carcass yield.