Effects of Dietary Mannan Oligosaccharide and Fructo Oligosaccharide Combinations on the Culture Performance of Red Swamp Crayfish

This research explored the impact of dietary prebiotics on the growth performance of red swamp crayfish over two distinct 90-day trials (each with 3 replicates). In the first trial (initial weight: 0.085 g, 7 experimental groups), mannan-oligosaccharide (M0, M1, M2, M3) and fructo-oligosaccharide (F0, F1, F2, F3) were added at concentrations of 0, 1, 2, and 3 g kg⁻¹. The highest weight gain (WG) and specific growth rates (SGR) were recorded in the M3 group (WG: 8.05 g, SGR: 5.07) and F3 group (WG: 8.00 g, SGR: 5.06). Similarly, the M3 and F3 groups showed the most favorable feed conversion ratios (FCR) and survival rates (SR). In the second trial (initial weight: 0.087 g, 10 experimental groups), the combined use of MOS and FOS (M3+F3) delivered the best performance (WG: 8.82 g, SGR: 5.12, FCR: 1.29, SR: 93%), compared to the M1+F1 group (WG: 6.94 g, SGR: 4.86, FCR: 1.64, SR: 82%). While hepatopancreas tissues remained normal in all groups, the probiotic-supplemented groups exhibited significantly higher crude protein and lower fat content, total hemocyte counts, and intestinal bacteria counts compared to the control group (p<0.05). A combination of 3 g kg⁻¹ MOS and FOS is recommended to enhance crayfish farming productivity.