The comparative effects of dietary supplementation with Pediococcus acidilactici and Enterococcus faecium on feed utilization, various health-related characteristics and yersiniosis in rainbow trout (Oncorhynchus mykiss Walbaum, 1792)

This study examined the effects of feeding of two dietary probiotics on growth performance and feed utilization, intestinal colonization and related health criteria, biochemical parameters, hematological indices, and immune parameters and protection against Yersinia ruckeri in Oncorhynchus mykiss during a period of 56 days. The study included 3 groups:1(a control group of fish, 2) a group of fish fed with a basal commercial diet supplemented with 2 × 106 CFU g-1 Pediococcus acidilactici (PA-group and 3) a group of fish fed with a basal commercial diet supplemented with 2.5 × 108 CFU g–1 Enterococcus faecium strain IR5 (EF-group). Each group was run in triplicate. The PA-group and EF-group showed significant improvement with respect to WG, SGR, FCR, PER, lactic acid bacteria (LAB) (%) in intestinal, intestinal colonization (log CFU g–1), survival (%), RBCs, WBCs, hematocrit percentage (Hct %), and respiratory burst activity (RBA) levels, each of which was significantly higher than that in the control group (p