%X The use of probiotics, particularly fermented yogurt, in poultry diets has gained substantial interest due to their capacity to enhance growth performance, feed conversion efficiency, and nutrient absorption in broiler chickens. This study evaluated the effects of yogurt supplementation on broiler performance and nutrient utilization. Two hundred one-day-old Ross-308 male broiler chicks were randomly assigned to five dietary treatments using a completely randomized design. Each treatment group included five replicates with eight chicks per replicate. The dietary treatments consisted of a control diet (without yogurt), locally prepared yogurt (5 mL/L in drinking water), yogurt fermented with Lactobacillus acidophilus (LA, 5 mL/L), yogurt fermented with Streptococcus thermophilus (ST, 5 mL/L), and yogurt co-fermented with L. acidophilus and S. thermophilus (LA+ST, 5 mL/L). The performance and ileal digestibility of nutrients were measured. Results indicated that the average daily feed intake (ADFI) significantly decreased in the LA+ST group at 0–14 days, with an 11.7 reduction compared to the control. Broilers receiving yogurt demonstrated a higher average daily gain (ADG) at 0–14 days, with the LA+ST group showing an 8 improvement over the control. At 0–28 days, the LA+ST group maintained the highest ADG, 6.8 higher than the control. The feed conversion ratio (FCR) significantly improved with yogurt supplementation at 0–14 days. Compared to the control, FCR improved by 3.6, 7.9, 5.7, and 15.7 in the Local, LA, ST, and LA+ST groups, respectively. Additionally, yogurt fermented with specific lactic acid bacteria (LAB) significantly enhanced the ileal digestibility of dry matter (DM), organic matter (OM), crude protein (CP), crude fiber (CF), ether extract (EE), and total ash (TA). These findings highlight the efficacy of yogurt fermented with L. acidophilus and S. thermophilus as a dietary supplement to enhance growth performance and nutrient utilization in broiler chickens. © (2025), (Scienceline Publication). All rights reserved. %A Emran Hossain %A Minara Begum Munni %A Umme Salma Amin %A Mahabub Alam %A Shilpi Islam %A Nasima Akter %A Ahasanul Hoque %R 10.36380/jwpr.2025.5 %I Scienceline Publication %V 15 %P 53 -64 %D 2025 %J Journal of World's Poultry Research %L eprints1448 %K Broiler; Daily gain; Feed conversion ratio; Feed intake; Yogurt %T Effects of Yogurt Supplementation on Feed Efficiency, Growth Performance, and Ileal Nutrient Digestibility in Broiler Chicken %N 1