Organic anthelmintics in sheep

Graduate student final project report submitted to The Ceres Trust.

Project Leader: Kimberly A. Cash, Graduate Student, Lincoln University, Department of Natural Sciences

Major Advisor: Dr. Bruce C. Shanks · Lincoln University · Department of Agriculture and Environmental Sciences · 1220 Chestnut Street, 110 Small Animal Research Facility · Jefferson City, MO 65101 · (573) 681-5382 · [email protected]

Collaborators: Harley Naumann, Ph.D · University of Missouri-Columbia · Columbia, MO

Ceres Trust Funding Awarded: $10,000
Project Period: 2014-2015
Report Submitted: October, 2015


Gastrointestinal nematode parasitism is one of the greatest threats to economic sheep production in the United States. With increased incidences of anthelmintic resistance and constraints of organic production, there is heightened interest in alternative natural dewormers, such as plants containing condensed tannins (CT). Therefore, the objective of this study was to evaluate the effect of organic fermented Pinot Noir (PN) grape extract on parasite level and performance in Katahdin lambs. Katahdin ewe and ram lambs (n = 45; 23.13 kg ± 0.60 BW) were stratified by fecal egg count, weight, and sex, and were allocated randomly to one of three treatments: 1) an oral dose (10 mL per 4.54 kg of BW) of fermented PN grape extract at 7 days (D7) intervals, 2) the same dose at 14 days (D14) intervals, or 3) control (C; oral dose of water at 14 day intervals). Condensed tannins were extracted, purified, and standardized from organic PN and were found to have a concentration of 0.20 mg/mL. Lambs were housed on pasture with no additional feed, for the duration of the 63-day study. End of study (P = 0.05) and change from beginning to end (P = 0.04) fecal egg counts were higher in C versus D7 and D14 lambs. Change in packed cell volume percentage from start of the study to end differed (P = 0.05) between D7 and D14 lambs. Average daily gain and total weight gain were greater (P = 0.02) for D7 and D14 lambs compared to C lambs. Start, end and change BCS and FAMACHA© scores did not differ (P ≥ 0.50) across treatments. End monocytes and white blood cell counts were lower (P = 0.05 and P = 0.03, respectively) in D7 versus D14 lambs. Other blood parameter counts were similar between treatments. Therefore, fermented grape extract may be an effective organic and sustainable strategy for controlling nematodes and increasing performance in lambs.