The Effects of Feed Additives in Beef Finishing Systems and the Effect of Rumen Degradable Protein Supplementation in Corn Residue Grazing Systems with the Use of Distillers on Growth Performance

Authors

• Robert M. Jones, University of Nebraska-LincolnFollow

First Advisor

Galen E. Erickson

Second Advisor

James C. MacDonald

Date of this Version

12-2017

Document Type

Thesis

Citation

A thesis presented to the Faculty of the Graduate College at the University of Nebraska in partial fulfillment of Requirements for the Master of Science

Major: Animal Science

Under the supervision of Professor Galen E. Erickson and James C. MacDonald

Lincoln, Nebraska, December 2017

Comments

Copyright 2017, Robert M. Jones. Used by permission

Abstract

One receiving trial evaluated the effect of the feed additive monensin (trade name: Rumensin) on steer growth performance in the receiving period while evaluating the effects of two receiving vaccinations on morbidity and mortality of newly received calves. No differences were observed in growth performance, morbidity rate or mortality rate between treatments for the first 28 d of receiving. A finishing trial evaluated the effect of the feed additive ractopamine hydrochloride (trade name: Optaflexx) on feedlot growth performance and carcass characteristics of crossbred yearling steers fed to differing degrees of finish. Feeding ractopamine hydrochloride at 300 mg improved ADG, G:F, and HCW regardless of days on feed (i.e., degree of finish). A growing trial evaluated the performance effects of grazing steers on corn residue supplemented with modified distillers grains plus solubles (MDGS; 1.4 or 2.3 kg/d) with or without urea (0 or 0.05 kg/d). No differences were observed in growth performance suggesting that supplemental urea is not necessary when supplementing at least 1.4 kg MDGS to steers grazing corn residue.