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United States Department of Agriculture

Agricultural Research Service

Research Project: Improving the Efficiency of Sheep Production in Western Rangeland Production Systems

Location: Range Sheep Production Efficiency Research

Title: Evaluation of Columbia, USMARC-Composite, Suffolk, and Texel rams at terminal sires in an extensive rangeland production system

Authors
item Notter, David -
item Lewis, Gregory
item Mousel, Michelle
item Leeds, Timothy
item Zerby, Henry -
item Moeller, Steven -
item Kirschten, David
item Taylor, Joshua

Submitted to: Sheep Industry News
Publication Type: Popular Publication
Publication Acceptance Date: September 11, 2013
Publication Date: N/A

Interpretive Summary: Crossing proven, superior terminal-sire sheep breeds with well-adapted maternal breeds provide opportunity to increase lamb carcass value, while maintaining acceptable environmental adaptation in crossbred lambs. Large, lean terminal-sire breeds, such as the Suffolk and Columbia, have been typically used in extensive rangeland conditions. Relatively intense selection in these breeds for body weight and frame size has resulted in increases in growth rate but also concerns regarding fitness and survival rates of offspring. Recently, other moderate size terminal-sire breeds have been promoted as alternatives to Suffolk and Columbia breeds. Unfortunately, performance data of these alternative sire types as well as fitness data from traditional and alternative terminal-sire breeds are somewhat limited, especially from extensive rangeland production systems. Therefore, an experiment was conducted at the U.S. Sheep Experiment Station (USSES) to compare Columbia, USMARC Composite, Suffolk, and Texel sires in matings with Rambouillet ewes in an extensive rangeland production system. For nearly all traits measured, Suffolk rams were superior to USMARC Composite, Texel, and Columbia rams as sires of crossbred market lambs. Texel-sired lambs were superior to other breeds in loin muscle area at comparable harvest weights, produced acceptable carcasses when harvested at 110 lbs, and generally had favorable residual feed intake values. Overall, these results suggest opportunity to develop new composite lines that can combine favorable effects of the Suffolk and Texel breeds. Further, more intense selection for growth rates, loin muscle size, and perhaps efficiency of feed conversion are required in order for the Columbia to compete directly with the Suffolk as a terminal sire.

Technical Abstract: Crossing proven, superior terminal-sire sheep breeds with well-adapted maternal breeds provide opportunity to increase lamb carcass value, while maintaining acceptable environmental adaptation in crossbred lambs. Large, lean terminal-sire breeds, such as the Suffolk and Columbia, have been typically used in extensive rangeland conditions. Relatively intense selection in these breeds for body weight and frame size has resulted in increases in growth rate but also concerns regarding fitness and survival rates of offspring. Recently, other moderate size terminal-sire breeds have been promoted as alternatives to Suffolk and Columbia breeds. Unfortunately, performance data of these alternative sire types as well as fitness data from traditional and alternative terminal-sire breeds are somewhat limited, especially from extensive rangeland production systems. Therefore, an experiment was conducted at the U.S. Sheep Experiment Station (USSES) to compare Columbia, USMARC Composite, Suffolk, and Texel sires in matings with Rambouillet ewes in an extensive rangeland production system. For nearly all traits measured, Suffolk rams were superior to USMARC Composite, Texel, and Columbia rams as sires of crossbred market lambs. Texel-sired lambs were superior to other breeds in loin muscle area at comparable harvest weights, produced acceptable carcasses when harvested at 110 lbs, and generally had favorable residual feed intake values. Overall, these results suggest opportunity to develop new composite lines that can combine favorable effects of the Suffolk and Texel breeds. Further, more intense selection for growth rates, loin muscle size, and perhaps efficiency of feed conversion are required in order for the Columbia to compete directly with the Suffolk as a terminal sire.

Last Modified: 10/23/2014
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