¹Kafkas University, Faculty of Veterinary Medicine, Department of Animal Nutrition and Nutritional Diseases, TR-36100 Kars - TÜRKİYE
²Atatürk University, Vocational School of Health Services, TR-25000 Erzurum - TÜRKİYE
³Kafkas University, Faculty of Veterinary Medicine, Department of Histology and Embryology, TR-36100 Kars - TÜRKİYE DOI : 10.9775/kvfd.2025.34619 The aim of this study was to evaluate the effects of dietary supplementation with probiotics, prebiotics, and synbiotics on growth performance, carcass traits, meat quality, and histomorphological characteristics in broiler chickens. A total of 320 one day old broiler chicks were allocated to four dietary treatment groups, each comprising 8 replicates of 10 chicks in completely randomized design. The groups included: a control group (no supplement), a prebiotic group (1 g/kg β-glucan + mannan-oligosaccharide; BM), a probiotic group (1 g/kg Bacillus subtilis; BS), and a synbiotic group (0.5 g/kg β-glucan + mannan-oligosaccharide + 0.5 g/kg Bacillus subtilis; BM + BS). The results revealed that body weight (BW), body weight gain (BWG), and average daily feed intake (ADFI) significantly increased in the BM + BS group, while feed conversion ratio (FCR) improved compared to the control group (P<0.001). Furthermore, slaughter weight, hot and cold carcass weights, as well as heart and gizzard weights, were significantly higher in the BM + BS and BS groups (P<0.05). Histomorphological analysis showed that villus height to crypt depth ratio (V/C) was significantly greater in the BM + BS and BS groups, but lower in the BM group (P<0.001). Regarding meat quality, the BM + BS and BS groups showed increased brightness (L*), redness (a*), and yellowness (b*) values (P<0.05). In conclusion, the dietary synbiotics supplementation in broiler diets was shown to enhance growth performance, improve intestinal morphology. Keywords : Growth performance, broilers, prebiotics, probiotics, synbiotics