manner on fry fed diets enriched with 2 and 3% of peppermint
extracts (Table 7), being the highest increments obtained in fry fed
the highest peppermint concentration assayed, respect to the
values found in control fish. Similar results were obtained
regarding white blood cells, being the observed increments statistically
significant in all the fish fed peppermint enriched diets
(Table 7).
Hematocrit and hemoglobin values were also increased in all the
groups of fry fed peppermint enriched diets, respect to the values
found in control group although the observed increments were
only statistically significant in the group fed 3% and 2 and 3% of
peppermint extracts, respectively (Table 7). The dietary peppermint
supplements tested in the present study on fry Caspian white fish
have different effects on the number of blood leucocytes depending
on the leucocyte cell type. No significant differences were observed
in the number of blood monocytes and eosinophils among groups
of fish fed control diet or peppermint enriched diets (Table 7).
However, the number of blood neutrophils was increased in those
fish fed peppermint enriched diets, respect to the values found in
control fish, being the observed increments statistically significant
in those fish fed 2% and specially 3% peppermint enriched diets. On
the contrary, the number of blood lymphocytes decreased as a
consequence of dietary peppermint administration (Table 7), being
the decreases statistically significant in those fish fed the highest
peppermint concentration (3%), respect to the values found in
control fish.
3.5. Immune parameters in blood
Serum total protein, lysozyme activity and IgM levels, as well as
respiratory burst activity of blood leucocytes were also increased in
a statistically significant way (P < 0.05) in all the groups of fry fed
peppermint enriched diets, respect to the values found in control
group, being the highest observed increments in those fry fed 3%
enriched diets of peppermint extracts (Table 8).