Abstract
Wheat pasture is unique to the Southern Plains where income can be reaped from the grazed forage followed by a grain harvest. The performance by cattle grazing is excellent, but nitrogen intake is excessive, resulting in inefficient use. Highly digestible supplements that are low in protein have been shown to augment ADG and improve nitrogen utilization. At the Southern Plain Experimental Range near Fort Supply, OK, an experiment was conducted to examine a supplement high in digestible fiber at multiple level of intake with or without 66 g of lasalocid/tonne. Sixty-five steers (324 ± 0.52 kg) grazed 41-ha of irrigated wheat pasture for 64 d. The supplement (4-Square Stocker/Grower 14; 14% CP; Purina Animal Nutrition, Shoreview, MN) was placed in 1 of 2 SmartFeed Plus feeders (C-Lock, Inc., Rapid City, SD); 1 feeder with the control feed and the other contained lasalocid. Each feeder was programmed to allow maximum intakes of 1.2, 2.0, and 3.2 kg/d for 8 or 9 steers at each level. So, there were 24 non-supplemented, 21 energy supplemented, and 21 energy supplemented steers with lasalocid. Because steers had liberty to consume supplement at will and only limited by a maximum, actual supplement intakes were calculated for the grazing period and steer performances were regressed on supplement intakes. Each kilogram of supplement increased (P = 0.04) ADG by 73 g/d; however, lasalocid did not increase (P = 0.73) ADG (avg ADG = 1.7 kg). Total BW gain by each steer (kg) was increased (P = 0.04) 4.7 kg for each kilogram of supplement fed daily and again, lasalocid did not increase (P = 0.73) performance (avg total BW gain = 109 kg). Supplementation with a moderate CP feed increased the ADG of steers grazing winter-wheat pasture, but the addition of lasalocid showed no benefit in this experiment.
Effect of degree of processing supplemental corn on metabolizable protein of beef cows consuming low-quality forage supplemented with cottonseed meal
