Animal Science Department

 

Date of this Version

5-2013

Comments

A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Animal Science, Under the Supervision of Professors L. Aaron Stalker and Terry J. Klopfenstein. Lincoln, Nebraska: May, 2013

Copyright 2013 Adam McGee

Abstract

Two studies evaluated the impact of residue removal; study 1, grazed in the fall or spring, study 2, removed by grazing at two stocking rates, light (LG), heavy (HG), or baled(B). There were no differences in pre-grazing treatments for digestibility, CP, NDF, plant fraction as a percent of residue and kg/25.5 kg of grain. Digestibility was highest in husk and lowest in stem. CP was greatest in leaf blade and lowest in husk. NDF was highest in the leaf sheath and lowest in the cob while stem is the greatest percentage of the plant and husk the smallest. The fractions cattle consumed yielded 6-7 kg of residue per 25.5 kg of grain. LG cattle had greater BCS (P < 0.01) and BW (P = 0.03) post-grazing. Soybean yields were greater following corn residue grazing (P ≤ 0.01) in both fall and spring grazed treatments compared to un-grazed. Study two found no effect of residue removal on grain yield (P = 0.31).

An additional study evaluated the effect of plant density and maturity, moderately early maturing (MEM) hybrids or moderately late maturing (MLM) hybrids. All fractions had greater kg of DM/ha in MLM hybrids. Percent of husk and leaf blade were higher in MLM hybrids. Leaf blade and stem were only fractions with greater NDF in MLM hybrids. NDFD of stem and husk were only fractions greater in MLM hybrids. MEM hybrids had greater CP in leaf sheath and stem only. As plant densities increased kg DM/ha increased for all fractions but cob. Percentage of cob and husk in total residue decreased with increased plant densities. The kg of leaf blade/25.5 kg of grain was only fraction to increase with the increasing densities. CP decreased for all plant fractions as planting density increased. NDF increased for all fractions as planting density increased. NDFD only decreased for leaf sheath as planting density increased.

Advisors: L. Aaron Stalker, Terry J. Klopfenstein

Share

COinS