PSIX-35 Alternatives to antibiotic supplementation on broiler performance under highland conditions

Abstract

Abstract There is limited information on performance and gut microbiota balance response to alternatives to antibiotics growth promoters on broiler at high altitude and level of health challenge. Therefore, Two experiments were conducted to evaluate the effects of alternatives to antibiotics supplementation on broiler performance and health at 2500 m.a.s.l. In, Exp. 1, a total of 1080 day-old Cobb-500 male broilers were used in a completely randomized block design. Eight experimental diets containing 1) Negative Control (NC), 2) Bacitracin methylene Disalicylate at 55 mg/kg (BMD), 3) Direct fed microbial at 750 mg/kg (DFM) 2x1011 CFU/kg of lactic acid bacteria, 4) a blend of essential oils (150 mg/kg; EO), 5) combination of permeabilizers, organic acids and phytochemicals (0.1%, CN), 6) DFM+EO, 7) DFM+CN, and 8) EO +CN. Performance was evaluated through the feeding period of 42 d with a new litter. There were no significant differences in performance nor mortality rate during the whole feeding period. In, Exp. 2, 1232 one-day-old Cobb-500 male chicks were randomly divided into 56 experimental units and exposed to similar treatments as described on Exp. 1. Performance variables, and cecal-microbiota population were evaluated during 42-d with a re-used litter. Overall, daily gain was increased for BMD, DFM, and EO+CN compared to NC (P < 0.05). Feed intake was not altered by dietary treatment (P = 0.892). Feed conversion rate was improved by BMD and EO compared to NC (P < 0.05). Total coliform, and E. coli population was increased by DFM and CN compared to NC (P < 0.005). Total Enterobacteriacea was not altered by dietary treatment with exception of EO, that increased its population compared to remaining treatments (P < 0.001). Data form this experiments suggest that positive effect of organic feed additive supplementation, especially EO, depend on bird health challenge at high altitudes.