Dietary supplementation of β-glucan improves growth performance, the innate immune response and stress resistance of red sea bream,Pagrus major

Citation

Dawood MAO, Koshio S, Ishikawa M, Yokoyama S, El Basuini MF, Hossain MS, Nhu TH, Moss AS, Dossou S & Wei H (2017) Dietary supplementation of β-glucan improves growth performance, the innate immune response and stress resistance of red sea bream,Pagrus major. Aquaculture Nutrition, 23 (1), pp. 148-159. https://doi.org/10.1111/anu.12376

Abstract
A 56-day feeding trial was conducted to evaluate the effects of supplemented diets with β-glucan (BG) at four levels [0 (D1), 250 (D2), 500 (D3) and 1000 (D4) mg BG kg−1] on red sea bream, Pagrus major. The obtained results revealed a significant increase (P < 0.05) in final body weight, weight gain, specific growth rate, feed intake, body protein content, lysozyme activity and tolerance against low-salinity stress test in all BG-supplemented groups when compared with BG-free group. Furthermore, D4 group resulted in a significant increase in feed efficiency ratio, protein gain, protein and lipid digestibilities, serum bactericidal activity and peroxidase content when compared with D1 group (P < 0.05). Haematocrit and plasma protein content in D3 group were significantly higher than those in D1 group (P < 0.05). Interestingly, BG supplementation decreased glutamic oxaloacetic transaminase (GOT) in D2 group and reactive oxygen metabolites in D2, D3 and D4 groups when compared with D1 group. Following low-salinity stress test, significantly higher amounts of secreted mucus were observed in fish fed D2 and D4 diets than those from fish fed D1 diet (P < 0.05). In conclusion, the supplementation of BG improves growth, stress resistance and immune response of P. major.

Keywords
blood chemistry; dietary β-glucan; growth; immunity; red sea bream; stress resistance

Journal
Aquaculture Nutrition: Volume 23, Issue 1