Document Type

Thesis - Open Access

Award Date

1967

Degree Name

Master of Science (MS)

Department

Animal Science

Abstract

In 1918 the Bureau of Markets, now the Bureau of Agriculture Economics, of the United States Department of Agriculture inaugurated its market reporting service on livestock in Chicago. At that time a uniform standard was set up for market classes and grades of cattle. The use of these uniform descriptions for all classes and grades of cattle throughout the country by researchers, producers, selling and buying agencies and packers has contributed a great deal to the orderly marketing of cattle and to the reporting and exchange of research information. The grade of a particular animal is determined by the apparent relative excellence and desirability of the animal for its particular use, be it feeding or for slaughter. The grade for a feeder is based on its conformation, quality, breeding, constitution, capacity and condition. Slaughter cattle are graded on the basis of their relative excellence with respect to conformation, finish, quality and maturity or age (Snapp and Neumann, 1960). However, the grade placed on cattle does not necessarily always reflect the animal’s ability to perform in the feedlot or its carcass quality. Under present grading standards plainer, upstanding , rangy cattle as typified by dairy breeds are placed in the lower standard feeder grade, and when sold on a live basis for slaughter are usually placed in the standard or good grade. However, recent research on carcass characteristics with this type of cattle and the beef breeds has not shown as wide differences in value of the carcass as were commonly thought to exist. The fact that carcasses from dairy-bred cattle grade lower than those from beef type cattle grade is due mainly to their poorer conformation. Conformation has no effect on quality of the meat and Murphey et al. (1960) stated that finish was 4.5 times as important as conformation in predicting yields of closely trimmed, mostly bone-in retail cuts from the round, loin, rib and chuck. Recent changes in government grading standards, which put more emphasis on quality and less on conformation, has benefited plainer types of cattle somewhat on market grade. It appears to have been common in the past to feed lower grading feeder cattle with a low energy ration and not attempt to feed them to the higher slaughter grades. Recent research, however, has questioned this practice and suggests that higher energy rations may improve the performance and slaughter grade of this type of cattle considerably. The purpose of this investigation was to determine the effects of energy content of rations on performance of dairy-type and beef-type steers using Holsteins and Herefords as representatives of the two types. Another objective was to study the influence of final weight and condition on performance at each level of energy for the dairy-type and beef-type steers. Weight gains, feed consumption, feed efficiency and carcass characteristics were used as measures of performance.

Library of Congress Subject Headings

Beef cattle --Feeding and feeds

Meat

Format

application/pdf

Publisher

South Dakota State University

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