ABSTRACT
This study investigated effects of stocking rate on cattle performance, quality and quantity of corn residue, and impact of residue removal on grain yield for 5 yr at the University of Nebraska - Lincoln West Central Water Resources Field Laboratory near Brule, NE. Four removal treatments-1) no removal (control), 2) grazing at 2.5 animal unit month (AUM)/ha, 3) grazing at 5.0 AUM/ha, and 4) baling-were applied to a center pivot-irrigated corn field (53 ha). The field was divided into eight 6.6-ha paddocks to which replicated treatments were assigned. Samples of residue were collected in October and March (before and after residue removal) using ten 0.5-m quadrats per treatment replication. Residue was separated into 5 plant parts-stem, cob, leaf, husk, and grain-and analyzed for nutrient content. Esophageally fistulated cattle were used to measure diet quality. Cattle assigned to the 2.5 AUM/ha stocking rate treatment gained more BW ( < 0.01) and BCS ( < 0.01) than cattle assigned to the 5.0 AUM/ha treatment. Leaf contained the most ( < 0.01) CP and husk had the greatest ( < 0.01) in vitro OM disappearance (IVOMD) but the CP and IVOMD of individual plant parts did not differ ( > 0.69) between sampling dates. Amount of total residue was reduced ( < 0.05) by baling and both grazing treatments between October and March but was not different ( > 0.05) in control paddocks between sampling dates. As a proportion of the total residue, stem increased ( < 0.01) and husk decreased ( < 0.01) between October and March. Diet CP content was similar ( = 0.10) between sampling dates for the 2 grazing treatments but IVOMD was greater after grazing in the 2.5 AUM/ha grazing treatment ( = 0.04). Subsequent grain yields were not different ( = 0.16) across all 4 residue removal treatments. At the proper stocking rate, corn residue grazing results in acceptable animal performance without negatively impacting subsequent corn grain production.
