The objective was to evaluate yeast based prebiotics, in solid and liquid forms separately, as replacement of antibiotic growth promoters in broiler chickens. Basal starter (ME: 3000 kcal/kg; CP: 22%) and finisher (ME: 3200 kcal/kg; CP: 20%) diets were formulated to serve as control (CONT). Basal diet was fortified with either Zinc Bacitracin 10% (ZNBC) or Enramycin 4% (ENRA) at 500 and 250 g/ton, respectively; while solid prebiotics were supplemented at 50 (SP50) or 100 g/ton (SP100). Liquid form of prebiotics was given at 0.5 (LP 0.5) or 1.0 ml per liter (LP1.0) in drinking water. Starter and finisher diets were fed to six replicates of 12 broiler chicks each, from day 1-21 and 22-35, respectively. Total feed consumption of broilers on diets containing prebiotics was higher (P<0.05) than those given control diet during starter (1183 vs 1178 g/bird). In finisher phase, birds given diets supplemented with prebiotics had higher feed intake than those given antibiotics (2241 vs 1996 g/bird). Weight gain (1883 vs 1532 and 1604 g/bird), feed conversion ratio (FCR; 1.83 vs 2.08 and 2.11) and European Production Index (EPI; 291 vs 181 and 205) were better in prebiotics fed birds than on antibiotics or control during overall period. Inclusion of antibiotics and prebiotics in broiler diet resulted in lower Escherichia coli (E. coli) and Salmonella Spp. count than in control group (0.24 and 1.16 vs 1.53 10³ CFU/g and 0.15 and 0.42 vs 1.03 10² CFU/g, respectively). Dressing percentage was better (59.6 vs 57.9%; P<0.05) in birds given prebiotics than those on antibiotics. In conclusion, refined functional carbohydrate may be used as an alternative to antibiotics in broilers. Furthermore, liquid prebiotics seemed more effective than solid prebiotics in enhancing the growth performance during starter phase.

To Cite This Article: Ashraf S, Bhatti SA, Kamran Z, Ahmed F and Rahman SU, 2019. Assessment of refined functional carbohydrates as substitution of antibiotic growth promoters in broilers: effects on growth performance, immune responses, intestinal micro-flora and carcass characteristics. Pak Vet J, 39(2): 157-162. http://dx.doi.org/10.29261/pakvetj/2019.040