HYBRID AND PROTEIN SUPPLEMENT AFFECT GAINS OF CATTLE GRAZING MATURE CORN

摘要

Grazing unharvested mature corn can eliminate most harvest costs and feeding expenses. Limited research data are available on the effects of corn hybrid or protein supplement on rate of gain on cattle grazing mature corn. Three corn hybrids (high grain, silage, and 'Grazing Maize'), were grazed by yearling steers from 12 September through 5 December, after kernels formed their black layer . Every day, steers received a new, ungrazed strip of corn along with 2.5 Ibs of a supplement that contained .16to 1.34 Ibs of crude protein/steer. All treatments receive the same amount of new corn each day, with the amount provided determined visually so the hybrid with the most grain would provide sufficient area so steers would leave a small amount of corn uneaten each day. Highest average daily gain (ADG) was 2.88 lbs. Corn hybrid had very little effect on ADG. The ADG increased as supplementation of crude protein increased to .54 lbs daily but changed little thereafter. Efficiency of converting corn grain into liveweight gain was low, between 8.0 and 14.4, partly due to grain passing undigested through the steers into their manure and to individual kernels remaining unconsumed on the soil surface.