Improving small ruminant parasite control in New England

Improving small ruminant parasite control in New England

Summary

Gastrointestinal nematode infections are a serious economic problem for small ruminant producers in the Northeast, limiting their ability to raise sheep and goats on pasture. The Barber Pole worm, in particular, has caused massive economic losses in the south and is starting to make its’ presence felt in New England. The goal of this project is to improve the parasite control practices of farmers in the region through parasite control workshops supported by farm visits. Research will investigate the anthelmintic potential of the condensed tannins in cranberries and the effect of vitamin E supplementation on the host response to parasite infection. Direct participation in workshops followed by hands-on reinforcement of best management practices during on-farm visits will result in at least three hundred and sixty producers of sheep and/or goats reducing their cost of anthelmintic use by 50% ($2/animal) on 4,240 animals (Year 1 – $2,853, Year 2 – $5,706, Year 3 – $8,560 , Total – $17,119) by implementing some or all of the following practices: use of the FAMACHA system, body condition scoring, fecal egg counts for selective deworming, mixed species grazing and pasture rotation. In 2010 forty-seven small ruminant producers attended parasite control workshops, completed a comprehensive parasite control survey and participated in the farm visit portion of this project. Additionally, preliminary results from research conducted at the University of Rhode Island indicate that there is no effect of vitamin E supplementation on the fecal egg counts of lambs experimentally infected with the Barber Pole worm. Additional data is currently being analyzed and the results will be presented at upcoming meetings.

Objectives/Performance Targets

Performance Target. Three hundred and sixty producers of sheep and/or goats will reduce their cost of anthelmintic use by 50% ($2/animal) on 4,240 animals (Year 1 – $2,853, Year 2 – $5,706, Year 3 – $8,560 , Total – $17,119) by implementing some or all of the following practices: use of the FAMACHA system, body condition scoring, fecal egg counts for selective deworming, mixed species grazing and pasture rotation. Project duration: 3 years.

Milestone 1 (revised). Three hundred and sixty producers of sheep and/or goats will complete a comprehensive survey on their current methods, problems and costs associated with parasite control prior to participation in the farm visit portion of this project. A brief post-visit survey will be given to all participants during the winter following the visit to their farm. Key project personnel and the producer advisory council will use information from these surveys to further refine project and workshop topics. This will occur on an ongoing basis over the project period as producers are contacted. This milestone has been partially met. This milestone was modified based upon the recommendation of the SARE interview committee to require that all project participants complete a comprehensive survey prior to the first visit followed by a brief post-visit survey the following winter. A comprehensive producer survey was developed using surveymonkey.com and completed by 48 small ruminant producers.

Milestone 2. Research conducted at the University of Rhode Island will determine whether the currently recommended vitamin E supplementation has a detrimental effect on parasite resistance in sheep. Results will be presented to a wide audience (producers, extension agents, researchers) at regional and national meetings, published on extension sheets, summarized in agricultural publications and in scientific journals. This milestone has been partially met. The animal portion of this study was completed on December 14th, 2010. Quantification and characterization of worm burden and the analysis of tissue and blood samples is currently underway.

Milestone 3. Research conducted at the University of Rhode Island and Virginia Tech will determine whether the bioactive component of cranberry leaves has efficacy as a natural anthelmintic in sheep. Results will be presented to a wide audience (producers, extension agents, researchers) at regional and national meetings, published on extension sheets, summarized in agricultural publications and in scientific journals. This milestone has been partially met. A small amount of cranberry extract has been prepared for use in the egg hatch assay. An opportunity arose and was taken to test the anthelmintic efficacy of cranberry extract in C. elegans, a nematode commonly used to model biologic systems.

Milestone 4. 900 (24%) producers will attend a workshop providing comprehensive education on parasite control. Workshop participants will have the opportunity to be trained in the use of the FAMACHA system, gain experience performing fecal egg counts and will be able to sign up for on-farm visits. Two workshops per project year will be offered in Connecticut, Massachusetts and Vermont, one workshop per project year will be offered in Rhode Island beginning in April 2010. This milestone has been partially met. Two workshops were held in Vermont, one in Connecticut, and three in Rhode Island. There were no workshops held in Massachusetts. In addition, two workshops were held in CT and RI for veterinarians interested in receiving training in small ruminant parasite control (one workshop in each state).

Milestone 5. 365 (10%) producers will participate in two on-farm visits 10 to 14 days apart. Producers will gain hands-on experience in FAMACHA card scoring, body condition scoring and rectal fecal sampling. Analysis of samples obtained from these visits will provide farmers with information on the level of flock susceptibility to parasites, parasite identification and the degree of anthelmintic resistance on each farm to the de-wormer being used. Farm visits will occur during the summer of each project year. This milestone has been partially met. Forty-seven producers participated in the farm visit portion of this project (CT – 11, MA – 1, RI – 8, VT – 27) this past summer.

Milestone 6 (revised). 360 (10%) small ruminant producers will reduce anthelmintic use by using the FAMACHA© system, BCS and FEC to selectively deworm those animals infected with parasites. (Yrs 2-3). The number of producers has been changed to reflect the final performance target. This target has not been met as the follow-up survey to producers participating in farm visits this past year has not been conducted.

Accomplishments/Milestones

Milestone 1. Producer Survey
• A comprehensive producer survey was developed using surveymonkey.com. (June, 2010).
• Forty-eight producers completed the preliminary comprehensive survey. (CT -14, MA-1, VT-24 and RI-9) (June through September, 2010).
• In order for producers to be eligible to participate in the farm visits they were required to attend a parasite control workshop and to complete a comprehensive parasite control survey. The only state that was able to offer any parasite control workshops early in the summer of 2010 was Vermont. Therefore, the only producers that would be eligible to attend a workshop and complete the survey would be those producers that had attended parasite control workshops held prior to the start of this project. Other than Vermont, Connecticut was the only other state that had previously held parasite control workshops. Due to the small number of producers in Rhode Island, we were able to hold a couple of workshops in late July that then made these producers eligible to complete the survey.

Milestone 2. Vitamin E research.
• The animal portion of this study was started in June and completed on December 14th, 2010.
• Supplementation of vitamin E by injected resulted in the lambs developing fevers in response to the injections. Therefore, after the first two injections of vitamin E we switched to a daily oral supplementation of vitamin E.
• There was no effect of vitamin E supplementation on packed cell volume or fecal egg counts. Quantification and characterization of worm burden and the analysis of tissue and blood samples is currently underway.

Milestone 3. Cranberry research.
• An opportunity arose this past summer (2010) to test the anthelmintic efficacy of cranberry extract in a C. elegans assay. Cranberry extract exhibited anthelmintic activity at doses comprable to other natural products with anthelmintic activity. These results provide additional justification for the testing of cranberry extract in the egg hatch assay.
• A small amount of cranberry extract has been prepared for use in the egg hatch assay. The egg hatch assay will be conducted during the first six months of 2011.
• The testing of the cranberry extract in lambs will be moved to the summer of 2012 due to the late start of the project and the time needed to test the extract preliminarily in the egg hatch assay and the gerbils and then prepare the necessary amount of extract for the lamb study.

Milestone 4. Workshops.
• At the first meeting of the Advisory Council, Dr. Zajac presented the principles of parasite control and conducted the training in FAMACHA and body condition scoring.
• Two workshops were held in Vermont during June 2010 for those producers interested in participating during the summer of 2010.
• Two workshops for a small number of producers (~6) were held in RI during the last week in July 2010 in order to provide parasite training to those producers interested in participating in the study during this past summer and having completed the initial survey. A third workshop was held for a large number of producers in Rhode Island (~20) in October 2010. These producers will participate in farm visits during the summer of 2011.
• One workshop (~ 12 attendees) was held in CT during October 2010 for producers interested in participating in the farm visits during the summer of 2011.
• In addition, two workshops were held in CT and RI (one workshop each) for veterinarians interested in receiving training in small ruminant parasite control during October 2010. These meetings were initiated because we strongly felt that we needed to include more outreach to the regions veterinarians than was originally proposed. We hope to plan additional vet only meetings for veterinarians in Massachusetts and Vermont this coming spring and to explore the feasibility of including the parasite control information in future state meetings of the AVMA.

Milestone 5. Farm visits
• The delay in the start of the funding from SARE coupled with the time needed by the University of Rhode Island to activate this new grant and it’s associated subcontracts pushed the start of this grant well into the summer months, effectively shortening the period of time available to conduct the farm visits during the first summer. Additionally, the student that had been selected to assist with farm visits in MA was no longer available to work on the project due to the late start as well as the refusal of UMASS Office of Sponsored Projects to advance the funds necessary to begin work prior to the subcontract with the University of Rhode Island being finalized. The Co-investigators in Massachusetts did not have another student that was qualified to work on the project and did not have adequate time to hold any workshops (required for producer participation) nor the time themselves to conduct any of the farm visits in Massachusetts. Therefore, other than the small ruminants at UMASS, no other farms in Massachusetts participated in this study.
• We spent a considerable amount of time developing the informational packets that were distributed to interested producers. During the course of the summer, revisions were necessary in order to address problems that arose.
• Forty-seven producers participated in the farm visit portion of this project (CT – 11, MA – 1, RI – 8, VT – 27).
• The delay in funding also postponed the initiation of farm visits in CT, VT and RI and therefore the targeted number of farms for each state (CT – 30, VT – 35, RI – 7), with the exception of RI, was not reached.
• There was a large number of farms that had very few animals, or animals with very low fecal egg counts therefore, these farms did not require a second visit.
• We ran into some issues with the shipment of samples from Vermont and Connecticut to Rhode Island which resulted in some samples being lost and the farms being revisited. The shipping issues have been resolved.
• We found that some of the FAMACHA scoring was not being conducted in direct light, contrary to our established procedures. This was generally a result of the lack of appreciation by the student of the ramifications of conducting the FAMACHA in the absence of direct sunlight coupled with the unwillingness of the producer to move the animals outside. Students will be more intensively trained on the standard protocol and all producers will be required to provide the means to constrain the animals in direct light.
• The students conducting the farm visits also had a tendency to conduct the FAMACHA and body condition scoring themselves, instead of working with the producer to score the animals, thus reinforcing the producers workshop training. This issue will be addressed for all farm visits moving forward.
• We also conducted some farm visits during the month of September that will not be offered in the future, as the effect of decreasing daylight and nighttime temperatures confounded the results of the fecal egg counting.
• The large number of fecal egg counts that will be conducted by the University of Rhode Island in the coming summer will necessitate additional student help. Funding is being secured to meet this need.

Milestone 6. Change in behavior.
• As the post-surveys have not been completed yet there is no information to report for this milestone.

Impacts and Contributions/Outcomes

• An advisory council, consisting of respected sheep and goat producers from all participating states, was formed and met for the first time last May.
• Forty-nine producers completed a comprehensive parasite control survey. Several producers expressed satisfaction with the survey questions asked and the time required to complete the survey.
• Six parasite control workshops for small ruminant producers were held in three states. There was overwhelmingly positive feedback from these workshops.
• Two parasite control workshops for veterinarians were conducted in CT and RI. One veterinarian commented that this was the best educational workshop that they had ever attended. All veterinarians attending these workshops expressed support for the goals of the project and appreciated the value we placed on including them in the planning and implementation of the project.
• Forty-seven producers participated in farm visits. In general, the majority of producers were very motivated to participate in the farm visit portion of this project and were more than willing to fulfill all of the pre-visit requirements.
• Preliminary results from lambs supplemented with vitamin E prior to and during an experimental infection of Haemonchus contortus indicate that there was no effect of vitamin E supplementation on packed cell volume or fecal egg counts.
• An additional test of the anthelmintic activity of cranberry extract tested using C. elegans yielded promising results. These results provide additional justification for the testing of cranberry extract in the egg hatch assay in the upcoming year.

Collaborators: