Abstrakt: |
Globally, with the expansion of aquaculture, the demand for functional feeds is continuously increasing, and effort is in progress to improve the efficiency of the feed additives. Herein, nano-scale chitosan (CNP) with an average size < 35 nm was prepared by using an ionotropic gelation method, and a completely randomized feeding experiment in three replicates under mimic aquaculture conditions was conducted to evaluate its efficiency as feed additive with respect to micro-scale chitosan (CH). Three 35% protein experimental diets, C-0 without supplement while C-1 and C-2 supplemented with CH and CNPs, respectively, at the same inclusion level, i.e., 5 g kg−1 diet was prepared and fed to the respective groups of silver carp Hypophthalmichthys molitrix. The experiment was continued for successive 60 days. The results indicated most significant (P < 0.05) effect of CNPs on the growth performance parameters (% weight gain, specific growth rate, and average daily weight gain), feed conversion ratio, non-specific immunity (WBCs count, lysozyme activity, immunoglobulin levels, phagocytic and respiratory burst activities), and resistance against Staphylococcus aureus infection. However, CH-supplementation did not show any profound effects on the growth rate (P < 0.05) with decreased plasma cholesterol level (P > 0.001). Our results indicate the improved efficiency of CNPs and recommend it as a feed additive to enhance fish productivity and fish immune response towards the invading pathogens. [ABSTRACT FROM AUTHOR] |