The effect of dietary propolis and pollen extracts on growth performance and haematological responses of rainbow trout (Onchorhynchus mykiss)

The aim of this study was to determine the effect of propolis and pollen extract on biochemical and haematological parameters of Onchorhynchus  mykiss. One hundred and eighty healthy fish, O. mykiss (mean weight 20.57±4.48 g) were used for growth performance and haematological assays. They were randomly selected, and distributed among fifteen 600-L fiberglass tanks as three treatments (1% Pollen, 1% Proplils, 0.5% Pollen + 0.5% Proplils as groups 1-3, respectively), negative control as group 4 in triplicates at density of 30 fish each. After 8 weeks of the experiment, which the fish fed supplemented diets, final weight of all treatments showed no significant difference (p> 0.05) as well as WG and DGI. Definitely, all the treatments of the mentioned criteria showed a significant increase (p< 0.05) compared to control group. On the other hand, FCR showed a significance difference (p= 0.00) among the treatments and control so that its value for the group 3 was the minimum one (1.84±0.05) and followed by group 2 (2.36±0.03). Some criteria containing Hb, RBC, Hct and WBC showed a remarkable increase (p< 0.05) in group 3 compared to other groups while MCV and MCH was significantly lower in group 3 (p< 0.05).