Effects of Dietary Mannan Oligosaccharide on Survival,Growth, Physiological Condition,and Immunological Responses of Marron,Cherax tenuimanus (Smith 1912)

The efficacy of dietary supplementation of mannan oligosaccharide (MOS) (Bio‐Mos®, Aqua Grade; Alltech, Lexington, KY, USA) was evaluated on survival, growth, physiological and immunological parameters of marron, Cherax tenuimanus. Marron were fed six different isonitrogenous and isocalorific diets supplemented with 0, 0.05, 0.1, 0.2, 0.4, and 0.8% of MOS for a duration of 112 d and examined for survival and growth every 28 d. Physiological and immunological indicators were measured every 56 d. After 112 d, survival was the highest when marron were fed 0.2 and 0.4% MOS supplemented diets. Wet tail muscle index (TMIwet) and dry tail muscle index (TMIdry) of marron fed MOS supplemented diets were significantly higher (P < 0.05) than marron fed diet without MOS. Osmoregulatory capacity was highest in marron fed 0.4% MOS. Marron fed MOS supplemented diets had lower (P < 0.05) bacteraemia than marron fed diet without MOS. Hemolymph clotting time was the lowest and granular cells were the highest in marron fed 0.2 and 0.4% MOS. The results suggest that feeding 0.2–0.4% MOS in the diet increases the health status of marron.