With the objectiveof evaluating levels of lactose in diets for piglets weaned at 21 days of age,it was carried out an experiment with 72 animals, with average weight of 6.12kg, distributed in a completely randomized block design with four diets (0,4, 8, and 12% lactose), six replicates, and 3 animals per experimental unit.Animals were fed the experimental diets from 21 to 35 days of age and they werefed a lactose-free basal diet from 36 to 49 days of age. The lactose levelsdid not affect daily weight gain, feed intake and feed conversion of pigletsfrom 21 to 35 days of age. The use of lactose levels in the diets alsodid not affect performance of the piglets assessed from 21 to 49 days old. Dietsalso did not influence villous height, crypt depth and villous:crypt ratio. Lactoseresulted in greater diversity and balance of the intestinal microbial community. The Lactobalillus spp. richness increases with the additionof lactose in diet up to the level of 8% in relation to the total number ofintestinal microorganisms, which may a possible improvement of intestinal health.
