Nutrient mass balance and performance of feedlot cattle fed barley based diets in large pens in western Canada

Authors

Erin M. Hussey, University of Nebraska-LincolnFollow

Date of this Version

Spring 4-19-2012

Comments

A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Animal Science, Under the Supervision of Professor Galen E. Erickson. Lincoln, Nebraska: May, 2012

Copyright (c) 2012 Erin M. Hussey

Abstract

Three separate large pen commercial feeding trials with approximately 9,000 heifers with either eight or ten reps/treatment were conducted at a Western Feedlots Ltd.- High River, a commercial feedyard near High River, AB, Canada. For all three experiments, Near Infrared Spectroscopy (NIRS) was used to segregate feed barley. In Exp. 1, barley was segregated based on digestible energy (DE) content as predicted by NIRS and heifers were fed low or high DE barley, or a 50:50 blend of the two. Feeding low DE barley improved weight gain, dry matter intake (DMI), and mortality; with little effect on carcass composition compared to high DE barley. In Exp. 2, barley was segregated based on starch:neurtal detergent fiber (NDF) ratio. Barley starch:NDF greater than 3.25 was considered high starch:NDF, and less than 3.25 was considered low starch:NDF. In this experiment, main effects of high and low starch:NDF barley and inclusion of 0 or 20% corn-based DDGS were evaluated. Feeding low starch:NDF barley improved feedlot performance, increased dry matter (DM) removed from the pen, and slightly increased N loss due to an increase in N intake. Feeding 20 % DDGS increased DMI, had a slight negative impact on G:F, and increased N and P losses due to increased intake and no change in manure nutrients. In Exp. 3, barley was segregated based on starch:NDF ratio similar to Exp. 2. Main effects of high and low starch:NDF barley and inclusion of 25 or 48 mg/kg monensin were evaluated. Feeding LOW starch:NDF barley and 25RUM improved feedlot performance and carcass characteristics, with minimal effects on manure nutrients and nutrient losses.

Advisor: Galen E. Erickson