This study aimed to evaluate the effects of dietary bovine lactoferrin (bLF) on growth performance, Hemato-Biochemical parameters, non-specific serum immunity intestinal histology and handling and high density stress in Sterlet sturgeon ( Acipenser ruthenus ). For this purpose, four different concentrations of bLF (0, 200, 400 and 800 mg/Kg diet) were supplemented in the diet in triplicates and fish (initial mean body weight = 320 g) were fed for 46 days in Isfahan university of technology, natural resources farm ponds. Dietary bLF significantly affected on growth performance, specific growth rate and food conversation ratio in different groups of sterlet fish (p 0.05) but not affected on final weight. Lactoferrin not showed significantly differences on hematological parameters (white blood cells counts, hemoglobin, heamatocrite, and differential white blood counts) (p 0.05) But the number of red blood cells on 400 mg of lactoferrin was significantly higher than the control group. Lactoferrin also significantly increased the number of monocytes on 200 and 800 mg groups (p 0.05). Dietary bLF didn’t change serum total protein, globulin, and as well as cholesterol between experimental groups, but increase the albumin on 800 mg group, and also showed lower plasma level of triglyceride lipid as an indicator of a positive effect (p 0.05). The plasma iron and total iron binding capacity were not affected by dietary bLF among groups. Lactoferrin had no significant effect on aspartate transferase (p 0.05) But could be significantly reduced the Alanin amino transferase and Alkaline amino transfrase levels at 200 and 400 mg treatments (p 0.05). Lactoferrin also enhances the non-spesific immune parameters such as serum lysozyme, activity complement haemolytic and immunoglobulin M (p 0.05). Also In the case of intestinal histology showed a significant effect on increase the villi length. It seems that lactoferrin has had positive effects on lactate stress index and reduce the stress indicator on over time. In general it can be concluded that lactoferrin has the significantly effect on serum non-specific immune factors. Keywords: Bovine Lactoferrin, Sturgeon, Acipenser ruthenus , Physiology
