Synergistic effects of dietary sodium butyrate and Spirulina platensis on growth performance, carcass composition, blood health, and intestinal histomorphology of Nile tilapia (Oreochromis niloticus)

The present study evaluated the possible synergistic impacts of sodium butyrate and Spirulina platensis as a feed additive on growth performance, carcass composition, blood health, and intestinal histomorphology of Nile tilapia (Oreochromis niloticus). A control and three treated diets were supplemented with sodium butyrate (SB) 350 mg, Spirulina platensis (SP) lg and a mixture of 350 mg SB and lg SP/kg diet (SB/SP) respectively, were fed for monosex Nile tilapia (12.5 +/- 0.50 g, n=120) for two months. The results revealed higher growth performance (final weight, weight gain, weight gain rate, SGR and PER) compared to control group (CG) (P<0.05), with higher values being observed in fish fed SB/SP, and significant improvement in FCR and ECR values with the lowest values being recorded in fish fed SB/SP followed by SP, SB and CG. Biometric indices showed no significant effect except for fish length, the longest fish length was recorded in fish fed SB/SP followed by SP, SB and CG. There was a significant correlation (P<0.05) between the length and the weight among the experimental groups. Carcass composition showed highest value of total lipid content in fish fed SB/SP. Hematological parameters showed no significant differences except for the WBCs which decreased significantly in fish fed SB or/and SP in respect to CG (P < 0.05). Biochemical parameters of Nile tilapia showed the highest values of total protein and globulin in fish fed SB/SP and the lowest values of triglycerides, AST and ALP in fish fed SB/SP. Intestinal histomorphology showed significant increase in the intestinal villi length, villi surface area and goblet cells count and decreased inter-villi space in SB or/and SP in respect to CG. Conclusively, results revealed the importance of both SB and SP in tilapia diets to enhance the growth, intestinal histomorphology and fish health.