EFFECT OF PARTICLE-SIZE AND ADDITION OF SUNFLOWER HULLS TO DIETS ON THE OCCURRENCE OF ESOPHAGOGASTRIC LESIONS AND PERFORMANCE IN GROWING-FINISHING PIGS

Four treatments different in particle size distribution were applied t o 288 growing-finishing pigs to investigate its influence on the occur rence of oesophagogastric lesions and performance. Through differences in grinding, the four treatments were: (1) fine diet; (2) medium diet consisting of 50% of diet 1 and 50% of coarse diet 3; (3) coarse diet , (4) fine diet + 5% whole sunflower hulls. All diets were pelleted. A digestibility trial was carried out in parallel with pigs of approxim ately 55 kg and fed the fine and coarse diets. In order to obtain a me asured particle size distribution from pelleted diets, the particle si ze was measured by a dry and wet sieve method. Coarse milling caused a significant increase of growth performance from 25 to 45 kg live weig ht compared to the fine diet due to a higher feed intake. Feed convers ion was not changed in this part of the growing period. The use of hul ls in a fine diet showed a trend towards a decreased feed conversion. Average daily weight gain was not affected by treatment during the com plete experimental period from 25 to 110 kg live weight. Feed conversi on was increased by coarse milling of the diet in this period. Additio n of sunflower hulls decreased feed conversion in the same experimenta l period. There were no differences in mean dressing and meat percenta ge in pigs between treatments. Coarse particles in the diet had a nega tive influence on pellet quality. Pigs fed the coarsely milled diet or the fine diet to which hulls were added had a lower proportion of sto machs with severe lesions in the pars oesophagea. Growth performance w as not influenced by severe oesophagogastric lesions in this experimen t. (C) 1998 Elsevier Science B.V.