Research Accomplishment Reports 2007

Grading-Up to Hair Sheep Genetics in a Low-Input Production System

D.K. Aaron, D.G. Ely
Department of Animal and Food Sciences

 

Project Description

The sheep industry must reduce labor requirements and improve efficiency of lean lamb production if it is to remain economically viable. Traits that affect labor requirements include hardiness, parasite tolerance, and shedding of hair and wool to eliminate shearing. Traits that affect production efficiency include fertility, prolificacy, ewe and lamb vigor, maternal ability, and post-weaning lamb growth. Post-harvest traits affecting meat quality include fatness, muscling, and carcass yield. Meat quality is important to ensure an enjoyable eating experience by the consumer.

This project evaluates lean lamb production of hair sheep (White Dorper) in a pasture-based production system. During the past year carcass data were summarized on 132 wether lambs differing in percentage White Dorper breeding and raised on pasture. This is one of the largest studies ever conducted comparing carcass data of hair (White Dorper) versus wool (Polypay) sheep; it shows carcasses of White Dorper crossbred lambs compare favorably with those of Polypay lambs for most traits. These results were shared with sheep producers from Kentucky and surrounding states at the annual University of Kentucky Sheeprofit Day and at Eweprofit Schools in April, June, and October.

Another important issue involves susceptibility to internal parasites. Ewes developed as part of this project have been used to demonstrate a management program for control of Haemonchus contortus infestation.

Impact

The overall objective of the University of Kentucky Sheep Unit is to develop and promote adoption of programs and procedures that will lead to a more economically viable sheep industry in Kentucky and the nation. This project provides an evaluation of a major hair breed of sheep. Upon its completion, it will answer the question of how the White Dorper, a hair sheep breed, will fit the modern meat industry and how large and small flocks can be used in mainstream sheep production systems. By project's end, lifetime ewe productivity data will have been collected on a minimum of 132 ewes differing in percentage White Dorper breeding and over 200 wether lamb carcasses will have been evaluated for fatness, muscling, quality, and yield. Long-term efficacy of a management program for control of Haemonchus contortus in ewes will also have been evaluated. Accomplishment of project obectives will provide the sheep industry with a viable solution for improving economic efficiency while maintaining product quality.

Publications

Aaron, D. K., D. G. Ely, E. Fink, B. T. Burden, and M. M. Simpson. 2008. Carcass composition of Polypay versus White Dorper x Polypay Crossbred lambs (abstract) . J. Anim. Sci. (In Press).

Simpson, M. M., D. K. Aaron, E. Fink, B. T. Burden, and D. G. Ely. 2008. Control of Haemonchus contortus infestation in ewes with copper sulfate (abstract). J. Anim. Sci. (in press).