The aim of this study was to evaluate the effect of encapsulated and non-encapsulated probiotics on preruminant calves' performance and health status. Three probiotic bacteria were isolated, characterized, identified and propagated to be used as a probiotic supplementation in different forms (non-encapsulated and capsulated). Forty-five Holstein newly born calves were divided into three treatments (15 each). Control group T1 (calves were fed milk without any supplementation), T2 (calves were fed milk supplemented with 1 ml *10⁶ probiotic in liquid media) and T3 (calves were fed milk supplemented with 1 g * 10⁶ encapsulated probiotic). The newly born calves were fed their colostrum for three days, then they were fed 3.8- 4.3 kg milk per day and the quantity increased gradually to 5.750 kg milk, calves had a free access to starter feed from the fifth day post calving and weaned when eat 1.5 kg starter feed for three consecutive days. Calves were weighed monthly until weaning and growth rate was calculated. Fecal samples were collected monthly and at the end of the experimental period to ensure they are free from pathogenic E.coli and salmonella Spp < /em>., also the fecal samples were collected every day for one week after the end of the experiment for measuring total count of lactic acid bacteria. Blood samples were collected for complete CBC analysis and measuring immune parameters. Results revealed that, daily growth rate of calves in T3 tend to be significantly higher (P=0.075) than the other two groups. There is no significant differences between treatments and control in the lactic acid bacterial shedding in the fecal matter during the 1^st, 2^nd and 3^rd months of experiment and the week next to the end of the experiment. Complete CBC data showed normal values for the three groups, while a significant increase were shown in MXD and neutrophils at the 1^st month from calving in group (2) than other two groups. The effect of treatments on some biochemical blood parameters showed that, calves in the second group have lower (P<0.05) blood AST concentration at 1^st month than in T1 and T3, also ALP1 and ALP2 concentrations tended to be significantly (P=0.079, p=0.055 respectively) higher in the control groups (T1) than treated groups. Moreover data showed that calves in group T3 have lower urea concentrations at 2nd month than in T1 and T2, while cholesterol and T.G concentration was lower in calves in group T2 than control. Effect of treatments on some immunological blood parameters showed no significant differences between treatments and control in the concentrations of lysozyme, nitric oxide and IgG in the three different samples, while lysozymes activities showed increases in the treated groups than control with no significant differences. So it can be concluded that, probiotics supplementations improve calves health, immunity, growth performance and do not affect its biochemical and hematological parameters.