Effect of Pellet Size and Drug Concentration on the Efficacy of Romet-Medicated Feed for ControllingEdwardsiella ictaluriInfections in Channel Catfish Fingerlings

Channel catfish Ictalurus punctatus fingerlings in 30 net-pens in three ponds were naturally infected with Edwardsiella ictaluri. The fish were then treated by feeding Romet®-medicated feed of two different pellet sizes at two different Romet premix formulations. Fish fed any of the four Romet feeds had significantly (P < 0.05) higher percent survival than the nonmedicated controls. Fish fed small pellets of Romet-medicated feed formulated at 5 kg of Romet-30 premix per tonne of feed had significantly higher survival than fish fed large pellets of Romet-medicated feed formulated at 5 kg of Romet-30 premix per tonne of feed or fish fed large or small pellets at 15 kg of Romet-30 premix per tonne. The reduced level of Romet-30 premix (5 kg/ tonne) allowed fingerlings to be legally fed at 3% body weight; hence, more medicated pellets were available to more fish. Fish fed Romet-medicated feed formulated to be fed at 3% body weight (5 kg Romet-30 premix/tonne) gained significantly (P < 0.05) more weig...