Conservation and Utilization of Livestock Genetic Diversity in the United States of America through Gene Banking

Harvey D Blackburn,Carrie S Wilson,Bethany Krehbiel

doi:10.3390/d11120244

Harvey D Blackburn, Carrie S Wilson + Show 1 more

Open Access

https://doi.org/10.3390/d11120244

Copy DOI

Abstract

A germplasm collection curated by the United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Animal Germplasm Program contains of over one million samples from over 55,000 animals, representing 165 livestock and poultry breeds. The collection was developed to provide genetic conservation and security for the U.S. livestock sector. Samples in the collection span 60 years, suggesting a wide range of genetic diversity and genetic change is represented for rare and major breeds. Classifying breeds into four groups based upon registration or census estimates of population size of < 1000, < 5000, < 20,000, and > 20,000 indicated that 50% of the collection is comprised of rare breeds in the < 1000 category. As anticipated, collections for breeds in the < 20,000 and > 20,000 are more complete (86% and 98%, respectively) based upon an index combining the number of germplasm samples and the number of animals. For the rarest breeds (< 1000), collection completeness was 45%. Samples from over 6000 animals in the collection have been used for adding diversity to breeds, genomic evaluation, reconstituting populations, or various research projects. Several aspects of collecting germplasm samples from rare breeds are discussed. In addition, approaches that could be used to enhance the status of rare breeds via the repository use are presented. However, given the array of obstacles confronting rare breeds, the gene bank may be the most secure prospect for the long-term conservation of rare breed genetics.

Highlights

The task of conserving rare and/or minor breeds has been a global challenge for the past 20 to years, as noted by the development of the World Watch List for Domestic Animal Diversity [1] and subsequent State of the World Reports [2,3]
Animal agriculture contributes over 60% of farm gate receipts in the U.S The continued advancement of production efficiency will require the effective use of genetic variation
While it is often assumed that such breeds are an untapped genetic resource containing rare alleles not found elsewhere, definitive examples are largely missing from the literature

Summary

Introduction

The task of conserving rare and/or minor breeds has been a global challenge for the past 20 to years, as noted by the development of the World Watch List for Domestic Animal Diversity [1] and subsequent State of the World Reports [2,3]. Some successes to this end have been achieved, as evidenced by the increase in population size (or breed registration numbers) for some populations. Compounding these biological aspects, there is an insufficient number of breeders, as well as a lack of breeder longevity and the organization [7,8]

Methods

Results

Conclusion