Author
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Leymaster, Kreg |
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Submitted to: Hair Sheep Research Symposium
Publication Type: Proceedings Publication Acceptance Date: 9/20/2005 Publication Date: 4/18/2006 Citation: Leymaster, K.A. 2006. Use of hair breeds in integrated systems. Proceedings Hair Sheep Workshop. Virginia State University, Petersburg, VA, June 20-21, 2005. Available: http://www.sheepandgoat.com/HairSheepWorkshop/index.html. Interpretive Summary: Expansion of the U.S. sheep industry depends on improvement of reproductive efficiency and reduction of labor and inputs, so that sheep production becomes more practical and profitable. These issues relate to the concept of low-input, forage-based production systems that are growing in popularity in the U.S. Because the relative importance of traits depends on characteristics of specific production systems, the merit of breeds may differ in intensive and extensive production systems. Hair breeds are obvious genetic resources that merit evaluation relative to wool breeds under both intensive and extensive production systems. This concept of matching breeds to specific production systems is being tested in an experiment at MARC. The experimental objective is to evaluate production efficiency under both intensive and easy-care production systems of four types of crossbred ewes. Crossbred ewes were produced by mating Rambouillet, Dorset, Dorper, and Katahdin rams to Romanov ewes. The four types of crossbred ewes will be evaluated over three parities in each production system. Developing maternal lines as easy-care sheep and exploiting high levels of ewe and lamb heterosis effects in terminal crossbreeding systems is paramount. But easy-care breeds should address traits beyond hair production and parasite tolerance. To focus purpose and clarify direction, easy-care breeds should emphasize traits that affect meat production on a systematic basis. Use of easy-care breeds, terminal crossbreeding systems, and extensive production systems could define the meat industry of appropriate regions of the country. Technical Abstract: Expansion of the U.S. sheep industry depends on improvement of reproductive efficiency and reduction of labor and inputs, so that sheep production becomes more practical and profitable. These issues relate to the concept of low-input, forage-based production systems that are growing in popularity in the U.S. Because the relative importance of traits depends on characteristics of specific production systems, the merit of breeds may differ in intensive and extensive production systems. Hair breeds are obvious genetic resources that merit evaluation relative to wool breeds under both intensive and extensive production systems. This concept of matching breeds to specific production systems is being tested in an experiment at MARC. The experimental objective is to evaluate production efficiency under both intensive and easy-care production systems of four types of crossbred ewes. Crossbred ewes were produced by mating Rambouillet, Dorset, Dorper, and Katahdin rams to Romanov ewes. The four types of crossbred ewes will be evaluated over three parities in each production system. Developing maternal lines as easy-care sheep and exploiting high levels of ewe and lamb heterosis effects in terminal crossbreeding systems is paramount. But easy-care breeds should address traits beyond hair production and parasite tolerance. To focus purpose and clarify direction, easy-care breeds should emphasize traits that affect meat production on a systematic basis. Use of easy-care breeds, terminal crossbreeding systems, and extensive production systems could define the meat industry of appropriate regions of the country. |
