“…Virginiamycin (VIR), an antibiotic growth promoter, has been reported to improve the growth rate and food efficiency of broiler chickens (Eyssen and De Somer, 1963;Nelson et al, 1963;March et al, 1978;Hedde, 1983;Rosen, 1983;Leeson, 1984;Boorman, 1987;Daniels, 1989;Bartov, 1990). This is due, in part, to its energy-sparing effect, which in turn, increases dietary ME by 3-0-7-2% (Nelson et al, 1963;March et al, 1978;Boorman, 1987).…”