Probiotic bacteria may prevent haemorrhagic septicaemia by maturing intestinal host defences in Brazilian native surubins

The farming of hybrid surubins in Brazil has been affected by bacterial diseases. To avoid this problem, the development of prophylactics such as probiotics has proved to be a promising tool against bacterial outbreaks. This study evaluated the dietary supplementation with lactic acid bacterium Weissella cibaria and its probiotic action in the intestinal tract focusing the hemato‐immunological parameters, histology and electron microscopy. A total of 96 fish were maintained in a recirculation system and divided into 12 tanks, two treatments (supplemented and unsupplemented fish) and six replicates. Fish were fed supplemented commercial diet with W. cibaria for a period of 45 days, and the unsupplemented fish were with commercial feed without probiotic. The numbers of red blood cells, thrombocytes and lymphocytes were higher in supplemented fish after 45 days (P