Structural Analysis of Caribbean Hair Sheep Reveals Two Climate-Mediated Sub-Groups.

The US sheep industry has been in steady decline since the end of WWII. The national flock peaked at about 56 million head in 1942 and dropped to 7 million by 2000. However, the non-traditional market for lamb and sheep products has grown substantially in recent years. Consumers are attracted by the low-input and pasture-based production system of sheep. New producers are taking advantage of low start-up expenses and modest time commitment.

Hair sheep of Caribbean origin are an optimal breeds for organic producers, especially those in the Southeastern US. Lack of wool eliminates the cost of shearing and abrogates the need for docking and precautions against associated hazards such as flystrike. Hair sheep obviously outperform fleeced breeds in regions of higher temperatures and humidity, environmental conditions ideal for for internal parasites such as H. contortus. Caribbean hair sheep demonstrate robust performance even in the presence of drug resistant trypanosomes. Taken together these factors result in reduced maintenance costs, decreased labor demands, and an overall higher return on investment.

We performed whole genome structural analysis on sheep representing eight Caribbean breeds and all probable contributors to breed formation. Results show that Caribbean Hair Sheep fall into one of two climate-mediated subgroups and can be described by admixture of contributing breeds associated with economic and political dynamics initiated during the period of colonization of the New World.