This study determined the effect of feeding different types of amounts of dietary fiber (DF) on luminal environment and morphology in the small and large intesting of sows. It was shown that there was an increased retention time, decreased amount of material, and a decreased tissue weight after feeding the low-fibre diet compared to the high-fibre diet. It was also concluded that feeding the diet providing the greatest amount of fermentable carbohydrates resulted in significant morphological changes in the colon compared with the low-fibre diet.