This study aimed to investigate the effect of increasing the lactic acid bacteria (LAB) concentration isolated from ensiled Kumpai Tembaga on the growth performance, carcass yield, and meat quality in Pegagan ducks. A total of 100 Pegagan ducks aged were allocated at seven days into five groups with four replicates: Group 1 (control) and Group 2 to 5 (orally LAB addition with the concentration of 1x10 6 , 10 7 , 10 8 , and 10 9 CFU/ml, respectively). The measured parameters included growth performance, carcass yield, and meat quality. The LAB supplementation significantly affected (P<0.05) the weekly feed intake, body weight gain, and feed conversion ratio starting from the third week. Irrespective of the LAB concentrations, carcass, and breast cut weights increased (P<0.05) by 24 and 35.3%, respectively, after LAB supplementation compared to control. The percentage of breast meat and breast meat-to-bone ratio increased (P<0.05) by 4.0 and 48.05%, respectively, but the bone percentage decreased (P<0.05) by 9.5% after LAB addition. Again, irrespective of the LAB concentrations, the meat shear force declined by 48.05%. (P<0.05) after administering LAB compared to the control group. The free fatty acid level dropped by 31.68% in Groups 3 and 4 and continued decreasing by 44.10% (P<0.05) in Group 5. In conclusion, oral LAB supplementation with a concentration of 109 produced optimal growth performance after two weeks of administration. The LAB addition also improved carcass yields, which had a greater impact on the breast. The meat texture became more tender with a lower fatty acid content.