1. Introduction
Dietary antibioticgrowthpromoters(AGPs)havebeen
widelyusedinthepoultryindustryasaneffectivemeans
to improvegrowthperformanceandtreatbacterialdis-
eases (Baurhooetal.,2009). However,recentlyseveral
side-effects ofAGPssuchasthepresenceofantibiotic-
resistantpathogensandantibioticresiduesinpoultry
productshavebeenreported(Nakphaichitetal.,2011;
Nisha, 2008). Consequently,therehasbeenaworldwide
increaseintheregulationorbanoftheuseofAGPsin
poultry diets.Thisphenomenoncurrentlyforcespoultry