Biological and economic efficiencies of beef production systems using low-quality forages and improved pastures

Thirty-two crossbred beef cows in late-gestation were stratified by body weight (634 kg, SE 5.4) and placed in eight pens. They were fed an ammoniated wheat straw (AWS) based diet for a 106-d wintering period. Four pens received an exogenous fibrolytic enzyme for the last 79 d. The other four pens served as controls. A digestibility trial was conducted for the control and fibrolytic enzyme treatments during the feeding period. Daily intake was measured for the entire 106-d period.;Thirty-two crossbred beef pairs were stratified into four groups. Two pasture groups were composed of superior growth calves and two were composed of normal growth calves. One superior group and one normal group were assigned to either a green-creep grazing treatment or a creep grain treatment. Calves were allowed green creep or creep grain for 55 d prior to weaning at approximately 174 d of age. Postweaning, the calves were placed in their respective groups and moved back onto improved pastures for 47 d. Creep grain calves received supplemental creep grain ad libitum during postweaning grazing. All calves were placed in a feedlot following this period and started on a finishing ration until they reached slaughter weight. (Abstract shortened by UMI.)...