Document Type

Dissertation - Open Access

Award Date

2023

Degree Name

Doctor of Philosophy (PhD)

Department / School

Animal Science

First Advisor

Zachary Smith

Abstract

The goal of this dissertation was to understand the strategies needed to optimize performance of confinement fed beef cattle in the Northern Plains. This was accomplished through three objectives: 1) evaluate health, growth performance, and antibody titers in previously vaccinated, newly weaned calves administered a respiratory and clostridia vaccine upon arrival compared to no vaccination; 2) determine the influence of manger space restriction on program-fed feedlot heifers during the growing phase; and 3) to evaluate growth performance and carcass traits following transit of feedlot heifers sourced and finished in different regions of the United States. For objective 1, single-sourced, newly weaned steers [n = 70; initial body weight (BW) = 254±5.9 kg] were blocked by BW in a randomized complete block design (RCBD) of VAC (vaccinated for respiratory and clostridial diseases upon arrival) or NOVAC (not vaccinated upon arrival). Timing of vaccine administration did not appreciably influence 42-d growth performance and vaccinated calves had increased antibody titer response. For objective 2, Charolais × Angus heifers (initial BW = 329±22.1 kg) were used in a 109-d backgrounding study. Heifers were blocked by BW in a RCBD into one of two treatments: 20.3 cm (8IN) or 40.6 cm (16IN) of linear bunk space/heifer. Restricting manger space allocation from 40.6 cm to 20.3 cm did not negatively influence gain efficiency or the efficiency of energy utilization in heifers program fed a concentrate-based diet to gain 1.36 kg daily. For objective 3, yearling heifers (n = 190; initial BW 483 and 425 kg for SD and TX sourced, respectively) were used in a 2×2 factorial arrangement of origin state (SD vs TX) and finishing state (SD vs TX). Heifers transported to higher ambient temperatures had improved yield grades, but had reduced dry matter intake, quality grades and limited growth recovery. Heifers transported to lower ambient temperatures recovered growth and had improved quality grades at the same level of rib fat but had reduced yield grades. Collectively, these results indicate the management of cattle influences growth performance and that there are multiple ways to manipulate performance based on management decisions in each beef cattle sector.

Library of Congress Subject Headings

Beef cattle -- Feeding and feeds -- Great Plains.
Beef cattle -- Vaccination.
Beef cattle -- Growth.
Beef cattle -- Carcasses -- Quality.
Feedlots.

Publisher

South Dakota State University

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Beef Science Commons

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Rights Statement

In Copyright