The aims were to evaluate the effects of the addition of different probiotic concentrations (0; 200 and 300mg/kg of ration) in rations of pigs recently weaned and in different ages of slaughter, on the characteristics of the digesting system and performance. 35 weaned pigs were used, distributed in blocks randomized design in 3x2+1 (three probiotic concentrations x two ages of slaughter + group slaughter to the weaning). Five pigs were slaughter in the weaning day and the others to the 31 and 41 days of age. Were sampled segments of the duodenum and jejunum for counting villous, weighs the pancreas and liver and calculated the yield carcass. For diarrhea incidence and performance, 30 animals were used and the evaluations were accomplished in the following periods: P1 - 0 to 10, P2 - 11 to 20 and Total Period - 0 to 20 days after wean. There was not effect of the probiotic concentrations on the characteristics of the digesting system and the diarrhea incidence, however the weight gain and the feed:gain ratio were affected. The conclusion are: The gain weight and feed:gain ratio of piglets supplemented with 200mg of probiotic/kg of ration was better than the group supplemented with 300mg of probiotic/kg of ration. The different probiotic concentrations added in the piglets rations did not alter the characteristics of the digesting system, being showed alterations just in relation to the slaughter age.
Bacillus spp.; diarrhea incidence; swine; villous density