V. Morshedi - Persian Gulf Research Institute, Persian Gulf University, Bushehr, Iran
N. Agh - Department of Aquaculture, Artemia and Urmia Lake Research Institute, Urmia University, Urmia, Iran
F. Noori - Department of Aquaculture, Artemia and Urmia Lake Research Institute, Urmia University, Urmia, Iran
F. Jafari - Department of Aquaculture, Artemia and Urmia Lake Research Institute, Urmia University, Urmia, Iran
A. Ghasemi - Persian Gulf Research Institute, Persian Gulf University, Bushehr, Iran

Lactoferrin (LF) has been used as an immunostimulant in different fish species and have effects on growth and immunological parameters. The aim of this study was to evaluate the effects of dietary LF on growth and feeding performance, body composition, digestive enzymes activity, hematological factors, humoral immune response and expression of immune-related and growth-related genes in sobaity juvenile (Sparidentex hasta). One hundred and thirty five fish with an initial average weight of ۳۵.۶۴±۰.۳۰ g were fed for a period of ۸ weeks. Basal diet was supplemented with ۰ (control), ۴۰۰ and ۸۰۰ mg kg-۱ LF in a completely randomized design trial in triplicate groups. The results showed no significant differences in growth and feeding parameters and body composition between control and treatment groups (p>۰.۰۵). Moreover, no significant difference was observed in digestive enzymes activity, non-specific immune response, hematological parameters and immune-related gene expression (IL-۱β) between control and the treatment groups (p>۰.۰۵). Nonetheless, growth-related gene expression (IGF-I) of treatments and control group significantly varied (p<۰.۰۵). These results suggested that dietary LF used in this study is not appropriate for supplementation in the diet of sobaity juvenile as it did not influence the growth performance, feed utilization, body composition and the physiological parameters in this fish. This study encourages further research on different aspects of LF in sobaity culture with a clear emphasis on optimizing dosage levels.

Immunostimulants, Hemato-immunological factors, Growth performance, Physiological response, Gene expression, Sobaity sea bream (Sparidentex hasta)