Dietary chitosan nanoparticles enhance the growth, production performance, and immunity in Oreochromis niloticus

The use of safe supplements for the enhancement of fish production and health are vital for future advancement in aquaculture. A trial was carried out to explore the influence of chitosan nanoparticle (ChNP) supplementation on the growth, whole body composition, intestinal bacterial count and histomorphology, digestive enzymes, hematology, immune response, and liver status of Nile tilapia (Oreochromis niloticus). A total of 120 tilapia fish (average preliminary weight; 5.66 +/- 0.02 g) were divided into 4 different groups and fed on diets fortified with 0 (control), 1, 3, or 5 g ChNP per kg diet It was observed that the addition of ChNP at different levels significantly improved the growth performance, total feed intake, and feed utilization compared to the control group (p < 0.05), while the hepatosomatic index and survival rate did not vary significantly among the experimental groups. Furthermore, a significant increase in the crude lipid levels of the whole body was observed in fish fed on 3 or 5 g ChNP per kg diet A substantial increase in the counts of erythrogram elements and total white blood cells was evident with dietary ChNP supplementation. The serum total protein and globulin content, nitric oxide, ALT, and AST were also significantly improved by increasing the ChNP level in supplemented diets (P < 0.05). Further, the activities of enzymes amylase and lipase were notably enhanced in fish that were fed on the diets fortified with 5 g/kg ChNP. A concentration-dependent decline in the total anaerobic and aerobic intestinal bacterial count was observed after ChNP supplementation. No alterations in the anterior intestine histology were detected among the experimental groups. Ultimately, the addition of dietary ChNP had favorable growth promoting and feed utilization effects by enhancing the activities of digestive enzymes, inhibition of the growth of intestinal microbial populations, and improving certain indicators of innate immunity.