Ivermectin residue in vegetable plants and compost

Final Report for FNE12-750

Project Type: Farmer
Funds awarded in 2012: $8,976.00
Projected End Date: 12/31/2014
Region: Northeast
State: Massachusetts
Project Leader:
Amylynn Kemp
Alpaca Obsession, LLC
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Project Information

Summary:

The study is to determine if Ivermectin Residue would be found in vegetable plants and/or the vegetable when utilizing composted alpaca manure as fertilizer. The study was based on utilizing the alpaca manure as a fertilizer for organic gardening in which there has always been serious concern related to the possible residual effects of Ivermectin in the plant and ultimately in the food we consume.

Overall study results: Initial study results are very promising indicating that Ivermectin residue may not be present in the plant and ultimately in the food we consume. Used in the garden at a rate of approximately 3:1 alpaca manure to other top soil we confirmed that Ivermectin was detected in the garden soil through five garden soil tests at rates between .85 ppb and 2.4 ppb 2 and 4 months after application.  Further testing should be performed to validate these initial study results, as well as to provide more detailed timeframe for Ivermectin binding with the soil so that alpaca farmers are better able to manage their compost piles.

Ivermectin was be detected in the manure piles for up to 5 years of age with a limit of detection of 0.8 ppb.  The highest concentration is yielded when manure sampling is completed after the first couple of days following Ivermectin injection; the concentrations seem to decrease after the first few days.  Piles in sunlight had lower concentrations of Ivermectin.

Due to these preliminary tests, ecommendations would include:

  • consider keeping the pile in sunlight to assist in speeding up compost as well as binding the Ivermectin to the soil
  • turning the pile to expose to sunlight
  • smaller compost piles
  • keeping away from rivers, streams, and water supplies to ensure that Ivermectin does not leach into these water supplies.

Introduction:

In 2011 a study was approved by (SARE) Sustainable Agriculture Research & Education in order to determine if Ivermectin Residue would be found in vegetable plants and/or the vegetable when utilizing composted alpaca manure as fertilizer. The Study was based on utilizing the alpaca manure as a fertilizer for organic gardening in which there has always been serious concern related to the possible residual effects of Ivermectin in the plant and ultimately in the food we consume. There is no required testing for Ivermectin for Organic status. MSDS for Ivomec 1% Injectable reports that studies indicate that when Ivermectin comes in contact with soil, it readily and tightly binds to the soil and becomes inactive over time. The MSDS does not indicate the amount of time it takes to become inactive and the required amount of soil to bind with the Ivermectin. Reports have stated that this can take up to 2 years. Participants in the study were Amy Kemp, Alpaca Obsession, LLC, Deanna Panetta, and Dr. Stephen Purdy. Testing was performed by the Massachusetts Pesticide Analysis Laboratory at UMass.

Project Objectives:

Two gardens with vegetables will be compared: one grown without any alpaca manure applications (control) and one with alpaca manure from animals treated with Ivermectin. The control group will be taken from existing garden on the premises. No alpaca manure has ever been added to the existing garden. Organic fertilizer is purchased from Gardens Alive yearly. To verify the presence of Ivermectin in manure, various tests will be performed on the manure, the compost and the soil. Ivermectin injections are always recorded in our alpaca health documents to confirm that Ivermectin was given to all the animals. The garden will then be established at a rate of approximately 3:1 alpaca manure to other top soil to prevent burn in the tender plants as well as to be more realistic in the rate of manure utilized by most gardeners. As with the control garden, organic seeds will be utilized. We currently raise our garden plants beginning indoors in February utilizing garden lights and will plant extra seeds for the study group. We utilize a hydroponic method of raising the seeds. A student from the department of Veterinary and Animal Sciences at UMass Amherst will be active in helping to establish the garden and ensuring its success. Her advisor for this project is Stephen R Purdy, DVM, Director of Camelid Studies at UMass Amherst. Measuring results Testing will be completed by UMass Amherst. The analytical technique utilized to test for the Ivermectin compounds would be HPLC (high performance liquid chromatography) with fluorescence detection of the derivatized macrolide. Results will be analyzed by Stephen R. Purdy, DVM, UMass Amherst and Stephen Cole, PhD, Emory University, Atlanta, GA (statistician). The study will help alpaca farmers and the alpaca industry understand whether there is any possibility of contaminating food with Ivermectin as well as how to properly compost Ivermectin treated manure. If the study shows that the vegetable does not take in Ivermectin, then farmers in the Northeast can move forward with promoting and utilizing alpaca manure as a fertilizer, in their own fields, etc. Should the results show that Ivermectin is taken into the plants, then farmers can regroup and develop a new plan to understand the effects of alpaca manure on ornamental plants for example. Outreach plan One the study has been evaluated and analyzed, the results can be shared with other alpaca farmers through NEAOBA which is the New England Alpaca Owners Breeders Association of which our farm is a member as well as AOBA which is the US Alpaca Owners Breeders Association.

Cooperators

Click linked name(s) to expand
  • Deanna Panetta
  • Stephen Purdy

Research

Materials and methods:
And results

Analysis of the alpaca feces was first performed in order to establish any rates of residual Ivermectin. Limit of detection was established at 5.0 ppb for feces.

In 2012, the study began by taking the alpaca feces with confirmed Ivermectin and establishing two piles: one in the sun and one in the shade. After a month and a half, Ivermectin was still detected in both piles with the sun pile having less amount in ppb compared to the pile in the shade. Soil: Initial results of soil confirmed that Ivermectin would be present in a garden with alpaca compost.

Compost: Utilizing the feces tested above, two compost piles were established in order to determine the length of time and specific circumstances in which Ivermectin is present in alpaca compost. These two samples were taken from compost that was exposed to sunlight and compost that was in the shade. After a month and a half, Ivermectin was still detected in both piles with the sun pile having less amount in ppb compared to the pile in the shade; indicating that sun exposure may assist in speeding up the binding process with the soil.

 

Testing was also performed on well-established compost piles to determine how long Ivermectin would be present in an unturned pile of alpaca manure. For this testing, a sample was taken near the top of the pile (estimated to be about a year old) and at the bottom of an unturned large pile (estimated to be approximately 5 years old). In both cases, Ivermectin was detected. We also sampled a smaller manure pile that was approximately 4 years old in which no Ivermectin was detected. The limit of detection was 0.8 ppb, so this could mean that there was Ivermectin present but at a rate less than the level of detection.

 

Initial study results for compost: Based on the analysis, Ivermectin can be detected in samples from varying conditions. The highest concentration is yielded when collection is completed after the first couple of days following injection; the concentrations seem to decrease after the first few days.

 

Initial analysis of the alpaca compost piles confirms that Ivermectin is detected in compost pile years after Ivermectin injections are given. This may suggest that smaller and more regularly turned compost piles may sooner help with Ivermectin binding to the soil. Initial results are inconclusive as to timeframe for Ivermectin binding with the soil; it is possible the tested sample was defective which therefore yielded undetectable amounts. Further testing is needed on composted soil to determine at what timeframe the Ivermectin will bind to the soil and therefore be undetectable. These initial results confirm that Ivermectin would be present in a garden with alpaca compost.

 

Garden testing: Based on testing performed in 2012, we had a better understanding of when to select the alpaca manure and composted soil. We then established the garden at a rate of approximately 3:1 alpaca manure to other top soil to prevent burn in the tender plants as well as to be more realistic in the rate of manure utilized by most gardeners. In May 2013, we confirmed that Ivermectin was detected in the garden soil through five garden soil tests at rates between .85 ppb and 2.4 ppb. In August, we also sampled three locations in the garden to confirm Ivermectin was still present. Testing showed that Ivermectin was still present in the soil and at rates between 1.9 ppb and 2.4 ppb.

Over the course of the summer we tested Tomatoes (3 tests), Cucumbers (2), Cucumber stems (1) and leaves (2), Pumpkin flowers (1), stems and leaves (1), Bell peppers (1), Hot Peppers (1), Squash leaves (1), Baby lettuce (1), as well as some grass (1).

 

Limit of detection rates were established at .2 ppb for all samples, except .035 ppb for Tomatoes, .3 ppb for Cucumber leaves, 1.5 ppb for baby lettuce. In all tests, Ivermectin was not detected.

 

Initial study results for the garden: Based on the analysis, Ivermectin was detected in the samples of the garden soil and over a period of 3 months, at the same rate as initial testing, indicating that it does take some time for the Ivermectin to bind with the soil. Initial results indicate that the plants and/or fruit does not have Ivermectin at the detection rates established. This could mean that Ivermectin is present in the vegetation and/or fruit just not at rates detected.

Research results and discussion:

Overall study results: Initial study results are very promising indicating that Ivermectin residue may not be present in the plant and ultimately in the food we consume. Further testing should be performed to validate these initial study results, as well as to provide more detailed timeframe for Ivermectin binding with the soil so that alpaca farmers are better able to manage their compost piles. As Ivermectin can be detected in the manure piles for extended periods; recommendations would include:

  • consider keeping the pile in sunlight to assist in speeding up compost as well as binding the Ivermectin to the soil
  • turning the pile to expose to sunlight
  • smaller compost piles
  • keeping away from rivers, streams, and water supplies to ensure that Ivermectin does not leach into these water supplies.

 

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary

Education/outreach description:

An article was published of these results in a recent edition of the New England Alpaca Owners and Breeders Association newsletter 2015.

Project Outcomes

Assessment of Project Approach and Areas of Further Study:

Future Recommendations

Thiese results are just a preliminary survey of the presence of the compound Ivermectin in the manure, soil and plants.  While it is promising that none of the compound was detected in the plants at the lower limit of .8ppb, it is a concern that the drug remains in the environment for years.  These findings should help form the basis of a scientifically designed study to verify these results.

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.