Control of Haemonchus contortus in northern New England sheep and goats through manipulation of its winter ecology

Project Overview

Project Type: Research and Education
Funds awarded in 2014: $200,161.00
Projected End Date: 12/31/2018
Grant Recipient: University of Maine
Region: Northeast
State: Maine
Project Leader:
Dr. James Weber
University of Maine

Annual Reports

Information Products


  • Animals: goats, sheep


  • Animal Production: animal protection and health, grazing management, grazing - continuous, grazing - rotational, parasite control, preventive practices, stocking rate, therapeutics, winter forage
  • Education and Training: decision support system, demonstration, display, extension, farmer to farmer, mentoring, on-farm/ranch research, participatory research, technical assistance, workshop, youth education
  • Farm Business Management: apprentice/intern training
  • Pest Management: biological control, chemical control, integrated pest management, mating disruption, prevention
  • Production Systems: organic agriculture

    Proposal abstract:

    ABSTRACT PART 1: PROBLEM AND JUSTIFICATION Many of northern New England's small ruminant producers graze their animals on pastures to increase the sustainability and profitability of their operations. However, grazing's advantages are often negated by losses associated with parasite infested pastures, especially when Haemonchus contortus, the Barber pole worm, is present on a farm. Haemonchiasis is one of the most costly diseases, in terms of lost production and deaths, for small ruminant producers in northern New England. A 2012 Maine survey diagnosed Haemonchus present on over 95% of participating sheep and goat farms. Severe infestations of Haemonchus can cost over $100 per ewe annually through mortalities, decreased weight gain, and anthelmintic expenses. Parasitism-related losses will certainly grow worse in the near future as parasites become more resistant to current anthelmintics, and alternative parasite management strategies are sorely needed by the sheep and goat industries of northern New England. Haemonchus is a subtropical parasite whose larval stages are not tolerant to cold. The cold winter environment of northern New England provides our producers with an advantage over southern farmers because parasite- infected fields are likely to become free of Haemonchus larvae between grazing seasons. As a consequence, the only remaining population of overwintering Haemonchus on a farm are confined to the animals' digestive tract where they may be targeted through deworming or by delaying return to pasture until the adult worms grow old and die within the host's GI tract. Documentation of winter kill of Haemonchus larvae on pasture in our region will give farmers in northern New England a unique opportunity to eradicate Haemonchus from a farm through effective winter management of adult animals. Farm-wide winter eradication of Haemonchus has been demonstrated on Swedish farms and more recently on one central Maine farm. 

    Performance targets from proposal:

    The objective of this proposal is to develop and implement a practical winter eradication protocol for Haemonchus in northern New England, test it on commercial farms, then teach this protocol, as well as conventional diagnostic and treatment tools, to producers through seminars, hands-on learning, and Web-based modalities.  

    One hundred NNE sheep and goat producers adopt more effective parasite management strategies, including routine monitoring of Haemonchus levels in their sheep through FAMACHA and fecal egg counts. Sixty producers will also adopt at least three of the following cold weather management techniques to reduce or eliminate the shedding of Haemonchus ova on winter and spring pastures: 1. Winter dewormer treatment; 2. Hasten Spring rise through earlier lambing or increased photoperiod; 3. graze weaned lambs separate from dams on 'clean' pastures; 4. utilize appropriate pasture stocking rates and practice rotational grazing; 5. reduce egg shedding on early spring pastures through the use of a 'mud season' paddock. These management changes will positively affect the productivity of 2000 sheep and goats on 1000 acres of pasture, resulting in additional profits of $200.000 per year in the northern New England region. 

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.