Animal Science, Department of
First Advisor
James C. MacDonald
Date of this Version
2017
Document Type
Article
Abstract
Performance and profitability of steers grazing smooth bromegrass during the summer was evaluated. Steers grazed bromegrass with no supplement (CON), grazed bromegrass fertilized with 90 kg N/ha (FERT), or grazed bromegrass and were supplemented with distillers grains plus solubles (DGS) at 0.6% of BW (SUPP). Supplemented steers had increased ADG compared to CON and FERT steers. Profitability was greatest for the SUPP steers due to increased ending BW at the end of the grazing season. Steers grazing fertilized pastures were more profitable than CON steers due to increased stocking rate as a result of improved forage growth.
A 2-yr study was conducted to evaluate the effects of summer management strategies on finishing performance and profitability of steers. Treatments consisted of summer finished steers (SHORT), steers grazing smooth bromegrass and supplemented with DDGS at 0.6% of BW (SUPP), steers grazing smooth bromegrass with no supplement (UNSUPP), steers backgrounded in a pen to target ADG of 1.07 kg/d (HI), and backgrounded in pen to target ADG of 0.76 kg/d (LO). Increased ADG during the summer led to decreased DOF to reach equal finish. When compensatory growth was observed, steers backgrounded on pasture were more profitable than steers backgrounded in pens, however, compensatory growth was inconsistently exhibited and therefore may not be reliable. When fed to equal fat endpoint, steers backgrounded during the summer and finished in the fall had heavier HCW than summer finished steers.
A 2-yr study was conducted to evaluate the effect of different grazing intensities and stocking method on steer performance and animal gain/ha. Treatments consisted of steers continuously grazing smooth bromegrass and initially stocked at either 6.82 AUM/ha (LO) or 9.88 AUM/ha (HI) or steers rotationally grazing smooth bromegrass and initially stocked at 9.88 AUM/ha. Grazing strategy did not affect animal gain or gain/ha. Emphasis should be placed on managing an appropriate grazing intensity, rather than grazing method.
Three studies were conducted to evaluate the effects of supplementing cattle consuming forage diets with pellets containing CaO-treated corn stover and drymilling byproducts on animal performance. As supplementation rate with the pellet increased, so did ADG, while forage DMI decreased.
Advisor: James C. MacDonald
Comments
A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree Doctor of Philosophy, Major: Animal Science (Ruminant Nutrition), Under the Supervision of Professor James C. MacDonald. Lincoln, Nebraska: August, 2017
Copyright (c) 2017 Cody Alan Welchons