For performance parameters, pen means served as the experimental unit for statistical analysis. For digestive tract and carcass measurements, individual birds were considered as the experimental unit. All data were subjected to one-way anal-ysis of variance using the general linear models procedure of SAS software (SAS Institute, 1996). Statements of significancewere based on P < 0.05 unless otherwise stated, and significant differences between means were separated by the leastsignificant difference test.