1. USDA ARS, Dale Bumpers Small Farms Research Center, 6883 AR-23, Booneville, AR 72927, USA
2. USDA ARS, 141 Experiment Station Road, P.O. Box 350, Stoneville, MS 38776, USA
3. USDA ARS, Poultry Production and Product Safety Research Unit, 1260 W. Maple St., Fayetteville, AR 72701, USA