This study was designed to evaluate two feeding strategies that can replace the inclusion of in-feed antibiotics by medium-chain fatty acids (MCFA) from vegetal origin.

A total of 400 male Cobb 430 broiler chickens were randomly distributed into four treatments (n=10): NC, negative control, corn-soybean meal diet without any in-feed antibiotic growth promoter; PC, positive control, NC diet supplemented with bacitracin methylene disalicylate (BMD, 50 ppm); DIC1, NC diet supplemented with sodium salt of MCFA (Dicosan®, NOREL SA) at the rate of 1.5 g, 1.0 g and 0.5 g per kg diet during the starter, grower and finisher stages respectively; and DIC2, NC diet supplemented with sodium salt of MCFA (Dicosan®, NOREL SA) at the rate of 1.0 g, 0.5 g and 0.5 g per kg diet during the starter, grower and finisher stages respectively. Chemical coccidiostat (Diclazuril, 0.3g/kg) was used throughout the study period. The trial lasted 35d, and performance parameters were recorded weekly. Data were analyzed using a one-way ANOVA via SAS, with pen as the experimental unit and values were compared by Tukey’s test. Regarding body weight, there were significant differences at d7 being the birds from NC and DIC1 heavier than DIC2 (217ga, 212.8gab, 215.1gb and 207.9ga for NC, PC DIC1 and DIC2 respectively, P=0.007). At 14d, a tendency was observed where NC, PC and DIC1 tended to be different from DIC2 (558.7g, 555.8g, 552.1g and 537.2g for NC, PC DIC1 and DIC2, respectively, P=0.06). No more significant differences were observed in body weight along the study period, however, at the end of the study (35d) DIC1 birds were the heaviest (2410g, 2421g, 2453g and 2419g, for NC, PC DIC1 and DIC2, respectively). There were not significant differences in the FCR among treatments, numerically DIC1 had the lowest FCR globally (1.52, 1.49,1.46,1.52 for NC, PC DIC1 and DIC2, respectively). There was no statistically significant effect of the dietary treatments on mortality, productivity index (EPEF) and carcass traits of the birds.