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ARS Home » Southeast Area » Booneville, Arkansas » Dale Bumpers Small Farms Research Center » Research » Publications at this Location » Publication #368913

Research Project: Sustainable Small Farm and Organic Grass and Forage Production Systems for Livestock and Agroforestry

Location: Dale Bumpers Small Farms Research Center

Title: Investing in parasite resistance in sheep

item Burke, Joan
item MILLER, JAMES - Louisiana State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/2018
Publication Date: 2/1/2019
Citation: Burke, J.M., Miller, J.E. 2019. Investing in parasite resistance in sheep. Southern Section American Society of Animal Science Meeting. 97(Suppl. 1)75-76.

Interpretive Summary:

Technical Abstract: Genetic parasite resistance in sheep has become an important technology in the control of gastrointestinal nematodes (GIN) due to widespread anthelmintic resistant GIN. The USDA ARS sheep flock in Booneville, AR has been selecting for parasite resistance since 2012 through the use of estimated breeding values (EBVs) generated through the National Sheep Improvement Program (NSIP). Objective is to show value of resistance. Recently, replacement ewes (n = 69) and rams (n = 29) from the flock were offered for sale and a sale catalog with EBVs for growth, reproduction, and parasite resistance, and recent BW was available. There were 73 purchased by 13 buyers from 7 states. Of the ram lambs that sold, post-weaning fecal egg count (FEC) EBVs ranged from -29 to -100, but of the 17 ram lambs offered, only rams with values of -97 or better sold (-100 is the highest FEC EBV and values can reach > +500; the top 10% for breed are <-67 pre-weaning). The highest price ($654) offered for all sheep was on a ram with a FEC EBV of -100. All mature rams sold and their FEC EBVs ranged between -66 and -100; highest bids were offered to rams with -100. For ewe lambs, FEC EBVs ranged from 33 to -75. Higher prices were offered to ewes with better FEC EBVs (P < 0.001). For mature ewes sold, FEC EBVs ranged from 18 to -87 with higher prices offered to ewes with better FEC EBVs (P < 0.002). For all sheep, higher prices may have been offered for animals raised as multiples rather than singles (P = 0.05). Seedstock producers wishing to improve parasite resistance can benefit by using NSIP to increase resistance and sale price. The higher parasite resistance used by commercial producers will reduce the need for deworming lambs.