The current work was conducted for assessment impact of using locally produced probiotic bacterial strains on the production and reproductive performance of Holstein dairy cows, those probiotic strains were isolated from saliva and fecal matter of suckling calves and rumen liquor of dairy cows. Thirty multiparous Holstein dairy cows at last 3 weeks of pregnancy were allotted to two groups (15 per each). 1^st group was the control group (C), fed transition diet (close up diet then post calving diet) without probiotic supplement, 2^nd group was the treated group (T), fed the same transition diets improved with 10⁶ CFU/kg DM feed of the produced probiotic supplement. Daily milk yield of each cow were recorded for 3 months postpartum (PP). Results revealed that cows in the treated group significantly (P<0.05) lost less BCS till day 30 PP  than control then they gained more score at 3 months than control, probiotic supplementation non significantly (P≥0.05) increased average DMI throughout the whole experiment., probiotic supplementation improved (P≥0.05) average milk-to-feed ratio throughout the whole experiment. Treated group had a significant (P<0.05) increase in cholesterol and AST (Aspartate aminotransferase) levels than control. Milk yield non significantly (P≥0.05) increased during whole experimental period, moreover increased (P≥0.05) average milk production throughout the whole experimental period by about 7.3% compared to control, while probiotic supplementation non significantly (P≥0.05) increased average milk fat% and yield (kg/day) or average milk protein% and yield, while had no clear effect on average solid not fat, milk lactose and ash percentages or yield compared to control. The effect of probiotics on reproduction revealed that cows in treated group had shorter days open, lesser I.N, fewer repeat breeders and better uterine and cervical involution and better conception rate at 3^rd insemination (CR3) than control. So it can be concluded that, adding the produced probiotics supplement to dairy cows ration improved cows transition period BCS, milk production, milk quality and had a positive effect on reproductive performance and post-partum uterine involution.