Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Animal Science


In the past 10 to 20 years the cattle feeding industry has undergone many changes. A number of changes in environmental factors and management practices have created problems in the adaptation of newly arrived cattle to their new environment. Major problems are the high incidence of diseases resulting in extensive treatments, slow gaining cattle during the early stages in the feedlot, and costly death losses. All result in narrowed profit margins. Cattle are being sent to feedlots at an earlier age. The practice of holding cattle until they are mature or selling them as grass-fats has declined. Feedlot operators want light, fast gaining cattle that can be marketed at an earlier age ·so that efficient early gains can be realized. The fat cattle market has shown a preference for lighter carcasses. ·More is expected in feedlot performance as evidenced by the high concentrate rations that are used in many feedlots. Calves are weaned at an earlier age. This contributes to / insufficient immunity to many diseases and less resistance to stress associated with weaning and subsequent handling. After weaning, calves are being shipped further because of the availability of longhaul trucking facilities. They are handled more and have more owners because of the numerous market outlets, particularly auctions. They are grouped in bunches for further sale to those who need large numbers to fill their sizeable lots. Spread of disease from a few to many is often the result. The origin of cattle is often lost so that tracing disease problems or determining prior feeding or veterinary practices that have been used is nearly impossible. At the feedlot, cattle are fed in larger groups which further facilitates the spread of infectious diseases. More research has been done on breeding cattle for improving efficiency and rate of gain than on disease resistance breeding programs. Research on adaptation of cattle to the feedlot has not been as extensive-as research on the entire feedlot fattening period. Good feedlot performance often results from a fast finish even though a slow start has affected total feedlot efficiency. Most of the research conducted in connection with movement of feeder cattle has been after shipping. Several studies have been conducted to determine factors affecting amount of shrinkage and rate of recovery under various feeding and management systems. Several studies have also tested the effectiveness of antibiotics in disease prevention and in improving early feedlot performance following shipping. More recently, there has been considerable interest in various management practices and vaccination programs prior to weaning and shipping of calves. These preweaning and preshipping practices are referred to as "preconditioning". While the topic is of great current interest, very little controlled research is available upon which to base some of the advocated practices. The research reported in this thesis was conducted to obtain additional information on factors affecting shrinkage in shipping of feeder cattle and rates of recovery. Studies were also conducted to determine the effects of levels of protein in the rations and of an antibiotic and sulfa drug additive on incidence of disease and early feedlot performance following shipping or weaning and shipping of calves.

Library of Congress Subject Headings

Cattle -- Feeding and feeds




South Dakota State University