Sire-Progeny Testing Dorper

Adoption of genetic selection practices can directly improve the production efficiency and sustainability of the American sheep industry. Recognizing this need, Texas A&M AgriLife in conjunction with the American Dorper Sheep Breeders Society is currently hosting the first sire-progeny test for Dorper & White Dorper producers. This project will demonstrate the value of performance records and estimate breeding values for traits that positively impact commercial sheep production. The format for this test includes the consignment of top rams from seedstock producers to breed the Texas A&M AgriLife Dorper flock with all progeny being measured for growth, parasite resistance and carcass merit. The results from this test will be used to make sire group comparisons, generate estimated breeding values (EBVs) and provide a robust measurement of the genetic value of the rams for each of these traits. However, funds from this grant would support the cost of added components to this sire test to enhance its impact. More specifically, with the requested financial support comprehensive evaluation of carcass characteristics could be included such as tenderness, juiciness and flavor via Rapid Evaporative Ionization Mass Spectrometry (REIMS) technology. While these traits are not widely studied or selected for in American sheep populations yet, EBVs for eating quality are offered by Australian genetic evaluation programs. Information on eating quality captured from this test could provide a foundation for these same tools to become a reality for the United States sheep industry. Furthermore, funds from this grant would be used to enroll the flocks of ram consignees into the National Sheep Improvement Program (NSIP). Not only would this promote the needed adoption of quantitative genetic technology, but participation in the sire-progeny test by these newly enrolled NSIP members would create necessary genetic linkages between these flocks to increase the accuracy of EBVs. We aim to conduct this project with Dorper because of their immense popularity in commercial flocks in Texas. Visual selection is the dominant form of animal evaluation for seedstock operations, but this practice often misevaluates hard to measure traits such as parasite resistance and reproductive capability. Consequently, Dorper sheep are under-represented in NSIP compared to other breeds and there are few genetic linkage between the flocks that are enrolled. With support from NSIIC this breed could make significant progress towards a future enriched with adoption of genetic tools and thereby provide a model for other breeds that wish to make similar improvements.

Project Objectives

1. Include tenderness, marbling, juiciness and flavor profiling as a component of the Dorper Sire Progeny Test being conducted by Texas A&M AgriLife.

2. Enroll six new Dorper/White Dorper seedstock flocks into the National Sheep Improvement Program.

3. Enhance the genetic linkage between NSIP-enrolled Dorper/White Dorper flocks.

4. Provide technical assistance to new NSIP member flocks in order to support their continued participation in the program beyond the granting term.