Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Animal Science

First Advisor

A. Lowell Slyter


Sheep production in the United States is highly variable. The sources of this variation are many and may include breed, climatic condition, management system and selection emphasis. The sheep is a highly adaptable animal and the success of an operation may be due in part to the ability of producers to select breeds of sheep best suited to their situation. Over time, two distinct management systems have developed. The first of these may be termed the farm flock system. The farm flock system is typical of the eastern United States in the crop farming areas of the country. This system may include such practices as early fall breeding, drylot confinement during the winter months, early lambing and weaning and rapid feedlot finishing of the lambs. The second management system may be termed the range flock system. As the name implies, the range flock system is typical of the western range areas of the United States. This system may employ such management practices as late fall breeding, reliance on grazing and limited feed supplementation during gestation, spring lambing and summer grazing of ewe and lamb pairs. Although these two systems are quite distinct, considerable overlap between the systems does exist. It was the objective of this study to compare these two systems of management and to examine the effect on lifetime productivity of ewes. It was a further objective to compare three distinct breed combinations within both systems. The Targhee breed is typical of the range type sheep used in many sheep operations. The experimental design of the study allowed the examination of the effect of replacing one-half of the Targhee genetic base with either Suffolk or Finnsheep breeding. The Suffolk represents a typical farm flock type sheep noted for growth and carcass quality. The Finnsheep is a breed known for multiple birth and early maturity. This study was conducted over a 8-year period which allowed all ewes 6 years of production. The end points to evaluate production were kilograms of wool produced and kilograms of lamb weaned.

Library of Congress Subject Headings

Sheep breeds



Number of Pages



South Dakota State University


No Copyright - United State