Implementation of Improved Intestinal Parasite Management Practices on Maryland Livestock Farms

Project Overview

Project Type: Research and Education
Funds awarded in 2022: $165,354.00
Projected End Date: 11/30/2025
Grant Recipient: University of Maryland
Region: Northeast
State: Maryland
Project Leader:
Dr. Amanda Grev
University of Maryland


  • Animals: bovine, camelids, equine, goats, sheep


  • Animal Production: animal protection and health, parasite control

    Proposal abstract:

    Problem and Justification

    Gastrointestinal parasites affect virtually all grazing livestock.  Traditionally, parasite management involved the single approach of administering dewormer to all animals on the farm multiple times per year.  However, this practice has inadvertently resulted in the development of dewormer resistance, which represents a risk to livestock farmers in regards to animal welfare, environmental sustainability, and economic return.  The economic loss associated with dewormer resistance is two-fold because it represents a direct cost to the farmer and limits the number of fully effective dewormers available in critical animal health situations.  Dewormer resistance has been well-recognized in small ruminants, and the concern for the development of resistance in parasites relevant to other livestock, including cattle and horses, is growing. Therefore, it is necessary for livestock farmers to adopt new ways of controlling parasites in their animals.

    Solution and Approach:

    To mitigate the development of dewormer resistance and improve the economic return of dewormer administration, farmers must become more selective in their use of dewormers and utilize other management strategies, such as good pasture and animal management, to control the parasite load in their animals.  To that end, this program aims to highlight the components of a successful parasite management program and help farmers understand how these strategies can be applicable in their specific situation.  We will utilize a combination of one-on-one consultations and field day instruction events in order to help livestock farmers in Maryland learn how to: 1) employ good pasture management practices to control parasite load; 2) monitor parasite load to determine if and when dewormer application is necessary; 3) adopt one of several selective-deworming strategies; 4) utilize appropriate techniques for selecting and administering a dewormer; and 5) evaluate the performance of a dewormer on their farm.  One-on-one consultations will focus on building individualized parasite management programs for participants and teaching them to apply these strategies in their own unique situations.  On-farm field days will also focus on teaching these strategies and provide an opportunity for participants to ask questions and learn about the experiences of each field-day host farm in the context of parasite management.  Post-participation surveys will be conducted to document knowledge gain and behavior changes that occur as a result of this program.  Two research studies will be carried out in order to document the effects of 1) improved pasture management on apparent parasite load of pregnant dairy heifers; and 2) forage type (annual vs. perennial) on parasite load of beef cattle and sheep.  These studies will provide data to further support the benefits of using pasture management to help control parasites in livestock. 

    Performance targets from proposal:

    We estimate that 30% of program participants (54 farms) will make at least 1 alteration to their parasite management program, which will affect approximately 1,080 animals and 2,500 acres.  Utilizing these practices will reduce the amount of dewormer purchased and applied by each of these farms by 30%, resulting in an annual savings of $3/head/year.

    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.