Effect of particle size and addition of sunflower hulls to diets on the occurrence of oesophagogastric lesions and performance in growing-finishing pigs

Abstract

Four treatments different in particle size distribution were applied to 288 growing-finishing pigs to investigate its influence on the occurrence 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 approximately 55 kg and fed the fine and coarse diets. In order to obtain a measured particle size distribution from pelleted diets, the particle size was measured by a dry and wet sieve method. Coarse milling caused a significant increase of growth performance from 25 to 45 kg live weight compared to the fine diet due to a higher feed intake. Feed conversion was not changed in this part of the growing period. The use of hulls in a fine diet showed a trend towards a decreased feed conversion. Average daily weight gain was not affected by treatment during the complete experimental period from 25 to 110 kg live weight. Feed conversion was increased by coarse milling of the diet in this period. Addition of sunflower hulls decreased feed conversion in the same experimental period. There were no differences in mean dressing and meat percentage in pigs between treatments. Coarse particles in the diet had a negative influence on pellet quality. Pigs fed the coarsely milled diet or the fine diet to which hulls were added had a lower proportion of stomachs with severe lesions in the pars oesophagea. Growth performance was not influenced by severe oesophagogastric lesions in this experiment.