Resumo

Healthy animals are known to exhibit proper gastrointestinal functionality, which is sustained by a balanced microbial community composition. However, alteration of the gastrointestinal microbial community may result in effects that are not restricted to the intestinal milieu. Recent studies indicate that probiotics and prebiotics can help to promote intestinal microbial balance. The present study aimed to evaluate the influence of a multi-strain probiotic preparation and a prebiotic preparation (mixture of inulin and fructooligosaccharides) on the hematopoietic tissue and zootechnical performance of Rattus norvegicus. The probiotic preparation consisted of a “pool” of lactobacilli comprised of the following species: Lactobacillus casei ATCC 7469, L. plantarum ATCC 8014 and L. acidophilus ATCC 4536. The experiment lasted 180 days. Feeding was ad libitum. Sixty male, four-week old animals were used, which were kept individually in plastic cages at room temperature. The animals were divided into three groups (A, B and C) containing 20 animals each, and received different treatments, as follows: A – Negative control; B – Daily probiotic doses; C – Daily prebiotic doses. Results regarding leukogram analysis have shown an increase in total leukocyte counts in all groups. This could be explained by the fact that the experiment was carried out initially during weaning period. Total leukocyte increase rates for groups A, B and C were, respectively: 135.48%, 229.90% and 213.12%. A significant increase in white blood cell counts after 180 days was observed in groups B and C in comparison to the control group, which was respectively of 21.21% and 51.77%. Regarding zootechnical performance analysis, group C animals presented higher feed conversion rates after 180 days in comparison to groups A and B. In conclusion, these results indicate that Lactobacillus based probiotics and fructan-based prebiotics may alter leukocyte kinetics in the hematopoietic tissue and improve zootechnical performance of Rattus norvegicus.