Performance of different breed types of ewes

The production of milk-fat spring lambs is the predominant system of commercial sheep production in Tennessee. These lambs are produced primarily by mating native, western crossbred, or fine-wool grade ewes to purebred rams of the mutton breeds, including Hampshire, Southdown and Suffolk. Most producers of spring lambs prefer to sell their ewe Iambs and to buy replacement ewes from western sources rather than produce home-raised replacements. One of the major problems confronting spring lamb producers in this area is a source of productive ewes. The breeding of replacement ewes has considerable economic significance to the producer for greater and more efficient production of lamb and wool. The breeding of the sire and dam is important factor in the production of a high percentage lamb crop and lambs with superior growth and meat qualities. Previous research has shown that crossbreeding is one means of increasing fertility and prolificacy in ewes and livability and growth rate in lambs, thus resulting in greater and more efficient lamb production. Three and four-breed crosses have been generally superior in performance to purebreds, grades and two-breed crosses in terms of overall productivity. The purposes of this study were; (1) to evaluate the adaptability and productivity of different kinds of high-grade and crossbred ewes from various sources for spring lamb production; and (2) to study the performance of lambs from different crossbreeding systems.