The effect of A-Max Ultra commercial prebiotic on growth performance, hematological and non-specific immune parameters of rainbow trout (Oncorhynchus mykiss, Walbaum 1792)

This study aimed to evaluate the effects of using A-Max Ultra commercial prebioticin rainbow trout (Oncorhynchus mykiss) diet on the growth performance, hematological indices, and innate immune responses. Fish with initial weight of 18.03 ± 2.14 g were stocked into 12 Cage in dimensions a 0.6×0.6×1 m3 in four concrete ponds. Four experimental feeds (triplicate) contained A-Max Ultra at levels of 0.0 (control), 1.0 (T1), 2.0 (T2), and 3.0 (T3) g k-1 were tested for 45 days. Fish fed prebiotic of 2 gk-1 had significantly higher final body weight, weight gain, and specific growth rate when compared to the control group (P<0.05). Among hematological parameters, red blood cells (RBCs), hemoglobin (Hb), and hematocrit (HCT) were significantly increased in fish fed 2 gk-1 of prebiotic in T2. At the end of the experiment, serum immune parameters of those fish fed A-Max Ultra including total protein and glucose content, lysozyme activity were not significant difference among all treatments. The obtained results revealed that 2 g k-1 A-Max Ultra could be used as a beneficial prebiotic to improve the growth performance and haemato-immunological responses in rainbow trout culture.