The effects of Guava (Psidium guajava) leaves powder on growth performance and some blood serum parameters in common carp (Cyprinus carpio) fingerlings

The aim of the present study was to evaluate the effects of dietary Guava (Psidium guajava) leaves powder (GLP) on growth parameters, feed utilization as well as some serum parameters of common carp (Cyprinus carpio) fingerlings. Common carp fingerlings (18.88±0.27 g) were supplied and stocked in twelve fiberglass tanks at density of 14 fish per tank. Fish were fed experimental diets contains 0 (control), 2.5, 5 and 10 g per kg GLP (4 treatments with 3 replicates). At the end of feeding trial growth parameters and feed utilization (final weight, SGR and FSR) as well as some serum parameters (Serum total protein, total Immunoglobulin and alkaline phosphatase activity) were measured. The results revealed that GPL treatments significantly increased growth parameters, weight gain and decrease feed conversion ratio (P<0.05). The best growth performance was observed in 2.5 g kg-1 GPL treatment. Regardless of inclusion level, supplementation of common carp diet with GPL increased serum total protein. Evaluation of serum total Ig and ALP activity revealed remarkable increase in 2.5 g kg-1 GPL treatments compared other groups (P<0.05). According to these results it can be concluded that GPL can be considered as beneficial feed additive for improving growth performance and immune status of common carp fingerlings. However, determination of the optimum inclusion levels merit further researches.