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 360 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 2011, 43 small ruminant producers, with a combined ownership of 1,151 small ruminants, 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 demonstrate that vitamin E supplementation decreased worm burden in lambs that correlated to a modest reduction in fecal egg counts but had no effect on packed cell volume. 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. During year two, the producer survey was revised in surveymonkey.com and completed by 36 producers. A brief post-visit survey will be sent to all participants from year one during Jan/Feb 2012 to determine whether or not the education opportunities and farm visits that occurred during year one translated into measurable changes in behavior during year two when the producers were managing on their own.

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. Approximately 75% of the analyses have been completed. The remaining analyses are currently underway. Preliminary findings from this research project were presented at the annual meeting of the Conference of Research Workers in Animal Disease (CRWAD) held December 4-6 in Chicago, IL.

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. Due to the success with the cranberry extract in the C. elegans model, it was deemed by the researchers on this project that testing the extract using the egg hatch assay was unnecessary. During the period of Jan to April 2012, the cranberry extract will be administered the Mongolian gerbil H. contortus model to test the efficacy of the extract using an animal model.

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 was met. Three parasite control workshops were held in Vermont, three in Connecticut, four in Massachusetts and none in Rhode Island (we had one major workshop in Oct 2010 for the summer 2011 parasite season). The first fecal egg counting workshop was held in CT this past year. In addition, three workshops were held for veterinarians interested in receiving training in small ruminant parasite control (one workshop in MA and two in VT).

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-three producers participated in the farm visit portion of this project (CT – 12, MA – 10, RI – 5, VT – 16) 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. A follow-up survey to producers from year one will be administered during Jan-March 2012 via surveymonkey.com or via hardcopy.

Accomplishments/Milestones

Milestone 1. Producer Survey

• The comprehensive producer survey was revised using surveymonkey.com to remove open-ended questions that made quantification of answers difficult. (June, 2011).
• Thirty-six producers completed the preliminary comprehensive survey. (CT -14, MA-7, VT-11 and RI-4) (May through November, 2011).
• 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. We ran into several roadblocks that affected survey completion: 1) the revision of the survey to remove open-ended question resulted in a survey with more questions. Several MA producers complained about the length of the survey even though, on average, it takes less than 30 min to complete. We are going to leave the coming years survey in its current form but provide a hard copy to producers at the parasite control workshops, go over the survey with them, provide an envelope that they can mail to us or give them the option of giving their survey (enclosed in an envelope) to the student at the farm visit. We feel that this will enable us to address their concerns and make it easier for them to complete this very important part of the project. 2) We held a workshop for RI producers in the fall of 2010 that would make them eligible to participate in the parasite project during the summer of 2011 once they completed the survey. However, when it came time for them to complete the survey and schedule a farm visit too much time had passed and it was extremely difficult, despite repeated phone and e-mail contacts, to get the producers to complete the survey so that we could schedule the farm visits. We felt that too much time had passed between the workshop and summer parasite season so we have decided to only offer workshops in the spring for Rhode Island. Our next Rhode Island workshop opportunities will occur in February (Blue Ribbon Forum in CT) and May 2012 (location in RI to be determined). As stated above, we hope to encourage survey completion by providing copies at the workshops and allowing producers to turn in the responses at the time of the farm visits. 3) Some producers that went online to complete the survey did not answer all of the questions therefore we will be following up with them this winter in order to complete each survey.

Milestone 2. Vitamin E research.

• Although there was no effect of vitamin E supplementation on packed cell volume, there was a significant reduction in worm burden in vitamin E supplemented animals. There was also a modest reduction in fecal egg counts. Quantification of tissue histology and serum immunoglobulin content is underway.
• Preliminary findings from this study were presented at the annual meeting of the Conference of Research Workers in Animal Disease (CRWAD) on December 5, 2011 in Chicago, IL.

Milestone 3. Cranberry research.

• In light of our results with the C. elegans assay with the cranberry extract we decided that the egg hatch assay would not be necessary. Our next step will be to administer the extract to Mongolian gerbils infected with H. contortus. This will happen during the winter of 2012. The extract needed for this gerbil study is currently being prepared. Once the animal work is complete on this study we will have to quantify the results and ultimately determine the effective doses we would like to administer to the lambs. After the dosages are determined, enough extract for the lamb studies has to be produced therefore it is likely that we will have to push the lamb study until the summer of 2013.

Milestone 4. Workshops.

• Development of material necessary to hold fecal egg counting training sessions for interested producers.
• From March 19th to 25th, 2011, four producer workshops (MA-1, CT–1, VT-2), three veterinarian workshops (MA-1, VT-2), one fecal egg counting workshop (CT) and the advisory council meeting were held.
• Three additional workshops/training sessions were held in MA (~10 producers), one in VT and three in CT (25 producers)

Milestone 5. Farm visits

• Forty-three producers participated in the farm visit portion of this project (CT – 12, MA-10, RI-5, VT-16).
• There was, again, 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. During the first season some producers were confused as to why we would not come out for a second visit therefore this year we made sure that the producers understood that they were only guaranteed one visit and if they had a sufficient number of animals with a large enough egg burden we would come back for a second visit to determine anthelmintic efficacy.
• The shipping system worked well this year.
• As mentioned in last year’s report, 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 some producers to move their animals outside. To prevent this from occurring this year an intensive training session, just for the students, was held on June 2, 2011. Consequently, we did not have this problem this past year.
• The first year students conducting the farm visits 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 was addressed during the student training and it is our understanding that the students worked with the producers this year to score the animals.
• We were able to secure funding for additional student help at the University of Rhode Island to help efficiently analyze the large number of samples arriving for fecal egg counting and fecal culture.

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, met March 21, 2011.
• Thirty-six producers completed a comprehensive parasite control survey. Several producers expressed some concern with the length of the survey and the amount of time they felt would be needed to complete the survey. Producers that completed the survey did not feel it tool an unreasonable amount of time (~ 30 min).
• Eleven parasite control workshops for small ruminant producers and one fecal egg counting workshop was held in three states. There was overwhelmingly positive feedback from these workshops.
• Three parasite control workshops for veterinarians were conducted in MA and VT. 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-three producers participated in farm visits. In general, the majority of producers were very satisfied with the farm visits.
• Vitamin E supplementation of lambs (10 IU of d-alpha-tocopherol/kg body weight/day), experimentally infected with Haemonchus contortus, decreased worm burden as compared to lambs supplemented with 5.3 IU of d-alpha-tocopherol/kg body weight/day.

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