1.  A Controlled Experiment To Measure The Effectiveness On Lambs Of Wormers That Conform To The New Organic Standards.  FNE03-482

Project Leader:   Jean Noon

78 Sunset Road

Springvale, Maine 04083





The newly implemented organic standards require producers to use natural materials to treat parasites in sheep and lambs.  In keeping with these standards I found during 2002 that the health, growth rate and feed conversion of my lambs had diminished alarmingly. 

During 2002 I tried using two commercial products that are organically approved.  Results were not satisfactory.  Feeding rates of these materials have not been adequately established for lambs.  Administration was recommended mixed in the feed and I found the lambs would not eat the mixtures all at once and I was concerned that some lambs would eat too much and some too little.  I was not convinced that they were effective.

I have searched the internet for the results of controlled experiments that would support the effectiveness of these materials and have found none that were convincing.  I did find several references indicating that garlic might be effective.  I have found out that garlic is known to contain 28 active antibacterial compounds.

For this SARE Grant I designed and implemented a controlled experiment to measure the effectiveness of various natural wormers and worming rates on parasites in lambs and at the same time attempted to identify the naturally resistant lambs for retention as breeding stock.




The Noon Family Sheep Farm is a Maine Organic Farmers and Gardeners Association (MOFGA) certified organic sheep farm.  We winter 50-60 ewes and lambs and have been raising sheep since 1970. Our original sheep were Columbias purchased indirectly from the UVM flock dispersal.  Since that time the flock has evolved into a commercial mix of Columbia-Rambouillet-Leicester-Suffolk, etc. bloodlines including colored and white wooled brood ewes.  We direct market value added lamb at select fairs and festivals through our lamb barbecue food booth.  We also sell hay, wool, yarn, sheepskins, and lamb at the farm.  Most of the year this is a part-time operation, the exception being at the fairs, during lambing, and during haying season.


We own ~75 acres that we purchased in 1974 and lease an additional 15 acres of hay land.  We have about 8.5 acres of pasture, and about 15 acres of our own hay land that we rotate the sheep onto after haying.  Our fencing is mostly electric, permanent and portable. The sheep harvest most of the second and third crop of hay directly.  The balance of our farm is in managed forest and wetland.  The 15 acres of hay leased from a neighbor is mostly sold in the field to support machinery, labor, and operating costs. 


This project used our own farm and flock as a laboratory. 


We have a sheep handling facility that is permanent and includes squeeze pens and chutes that make the physical handling of the sheep quite efficient.

Handling pens and chute



Dr. Tom Settlemire      

Bowdoin College                                            

Brunswick, Maine Katahdin Hair Sheep Project (SARE)


Dr. Settlemire was an invaluable asset to my work.  I visited his project and he demonstrated the sampling and testing methods that I used.  He read and made suggestions on my grant application and he reviewed this report.  He also provided me with some equipment such as graduated cylinders and some cylinder stands he had fabricated.  He also came to my farm to consult on my set up and helped me organize the experiment.  I attended the Katahdin Sheep Symposium and the FAMACHA training that he provided in October.  He also suggested I contact one of his student interns, Elizabeth McCain.


Elizabeth McCain


Elizabeth came to the farm several times to help me with sampling and fecal count measuring.  She was terrific and very fast at counting eggs!  A great hard worker and is now in grad school becoming a veterinarian with a deep interest in parasitology.


Mike Bukowski-Thall DVM                                       

Down Maine Veterinary Clinic 

Sanford, Maine


Dr. Bukowski-Thall was on call in case there were health problems that needed his attention.  His clinic also ordered the FECASOL for me which is the egg flotation medium used in the testing.


Diane Schivera M.A.T.                                              

Assistant Director of Technical Services
Maine Organic Farmers and Gardeners Service, MOFGA
294 Crosby Brook Rd.
PO Box 170 Unity, ME 04988
FAX: 568-4141                                                           


Diane encouraged me and came to the farm on a visit.  Her interest helped me persevere through the testing sessions.  She read my application and this report.




All lambs are numbered with ear tags at birth and records are kept of their date of birth, parentage, and type of birth. Lambing occurred during February and March.  The number of lambs included in the test was determined by the 2003 lamb crop (51).


Lambs were grouped in four groups. Groups were arbitrarily assigned by counting down the birth order (1,2,3,4; 1,2,3,4; …etc) without regard to birth type or sex.  Groups were all mixed together and raised in one flock separate from the adult ewes after weaning in late April.  .  After reexamining my management practices for 2002, I had introduced the lambs to the pasture with the ewes prior to weaning to try to get lambs eating grass sooner.  I changed my grazing strategies in 2003.  The lambs were introduced to pasture after weaning.  Lamb pasture had not been grazed by ewes since mid November.  I rotated the lamb pastures about a week after treatment.  I had only 4 paddocks to use and think that more would be a lot better.  Another technique that I use is to start the lambs in a small area of grass and move the fence out for them every day or even twice a day.  This way they graze better and do not contaminate the grass they are eating as much.

 Lambs are grazing a strip of new grass up to portable electric fence.



Group membership was determined by ear tag at sample times for treatment in the sorting chute.  Individual fecal samples and weights were collected and parasite loads measured and recorded by ear tag number starting in May and then every 2-3 weeks for the remainder of the summer.  Treatments were administered June 6, July 1, August 1, August 17, September 3 and September 9th. During August I separated the ewe replacement lambs into a their own group to conserve grain and keep them from becoming over weight.

Fecal samples were taken by placing the lamb into a crate (on the scale) in the sorting chute.  Then using a glove, a sample was removed from the lamb’s rectum.  2ml of fecal material is added to 28ml FECASOL (sodium Nitrate egg floatation solution).  If there was no sample to be had the lamb was released and tried again later.  Ear tag and sample numbers were recorded.  The lamb was then treated according to its group assignment.

            In order to have an accurate reading of parasite loading the eggs per gram system called the “Modified McMaster Egg Counting Technique” developed by ADVANCED EQUINE PRODUCTS was used.  This system involves the use of specialized green line slides that incorporate a fixed cover slide and a pair of grids that determine the volume of the sample that is viewed and a means to count eggs within that volume.  Eggs per gram are then calculated using a formula. The two grid numbers are added together and multiplied by 50 to determine the eggs per gram in the sample. (See source list)

Coccidia (Eimeria) was one of the parasites that I counted during my testing.  These are tiny parasites that live in the cells of the sheep’s intestines.  They are thought to be less of a threat to the health of the sheep as the sheep usually develop resistance to them over time.  They can however be problematic in lambs.  When you study my graph you will see that the garlic treatment did reduce the coccidia counts significantly prior to the drop in numbers in late June due to the natural rise in resistance immunity after exposure. 

Group 1 – CONTROL;  Group 2 – CRYSTAL CREEK;  Group 3 – GARLIC;  Group 4 – FARMSTEAD


The other parasite I counted was Haemonchus Contortus (H.Contortus) or the barber pole worm, which is a blood sucking intestinal parasite that is dangerous to lambs and has developed immunity to several commercial anthelmintics. 

Sept.3 two critically infected lambs in Group 2 were treated with garlic and all lambs were treated with garlic on Sept. 9


Lamb Flock Management:

All lambs were provided with free choice access to grain, pasture, hay, loose trace mineralized salt mixed 2:1 with Diatomaceous Earth, ground limestone, and water. Some experts are skeptical of the effectiveness of the DE.  Ground limestone prevents the occurrence of Urinary Calculi in ram lambs on a high grain diet.  


Group OneControl – Lambs that were not treated (unless they exhibited clinical symptoms and I determined treatment was needed for their survival and then they were to be eliminated from the experiment). 


Group TwoCrystal Creek organic wormer (Para- Tack Intestinal Cleanser, at a rate of 2 tsp. mixed with water to make a 1 oz. dose)


Group ThreeGarlic Juice at a rate of 1 tsp. Concentrated juice diluted with water to make a 1 oz. dose.


Group FourFarmstead Health Supply (1/2 tsp. Sustain, and 1 tsp. Restore mixed with water to make a 2 oz. dose) This mixture was too thick to administer as 1 oz.


To be perfectly fair to the two companies, I did not follow either one’s recommendations, which were a bit vague, and this may have compromised their effectiveness. 


My standard dosing syringe with backpack did not work with the dry mixtures from Crystal Creek and Farmstead.  They clogged it up.  Instead I used a single dose syringe with a 6” extension and washed and rinsed it thoroughly between lambs.  Crystal Creek and Farmstead both recommend mixing their products with the feed.  From experience I felt that I could not depend upon each lamb receiving an equal portion that way unless I had individual stalls (or a LOT of time) so I mixed these products with water.  I also wanted to run all the lambs together.  Treatments were measured and mixed fresh in batches at each treatment date.  Because the compounds do not suspend well the batch needed to be mixed each time a dose was drawn.  I discovered that the garlic solution could be administered with the standard backpack multiple dose syringe.(I used the single dose syringe until my last treatment on Sept. 8)

Lambs were all rotationally grazed together and moved onto clean pasture a few days after individual treatment.  I did not set aside quite enough “clean” space for the entire grazing season.  I think this resulted in the dramatic rise of parasite load that occurred during August.  I would like to study the timing of the parasite rise further as it is crucial to the management schedule.  The parasite rise may also be dependent on the weather.

Fecal egg counts were taken again two to three weeks after treatment. Weight gains and animal health was documented at each treatment and testing interval.  All the data I collected was put into a “Works” spreadsheet and sorted to generate charts

It appears from my data that garlic juice reduces the numbers of eggs of Haemonchus Contortus and Coccidia in fecal samples. The results were unexpected.  I have to admit I was skeptical about the effectiveness of any of the treatments.  My first surprise from the samples was the lambs did not show any infection of Haemonchus Contortus (H. Contortus) at the May baseline testing session.  There was only evidence of Coccidia.

During June there was a rise in both Parasites.  The H.Contortus was mostly well below 2000 eggs per gram (not considered dangerous).   The Coccidia was reading around 11,000 eggs per gram.  The garlic treatment group dropped to less than 4,000 eggs per gram Coccidia.

By July the coccidia had dropped in all groups including the control (no treatment).  This indicated a rise in the natural resistance or immunity toward the coccidia in all the lambs.  I did continue to count the coccidia in samples but it stayed below 2,000 for the remainder of the test period.

The 2003 lambs grew very well and the first ones were marketed during early June.  This caused the test group numbers to decline.  Most of the male lambs were marketed by the end of July and all were gone by Sept. 9.  This made the weight record averages for the test groups inaccurate and may have influenced the results.  Also we had a lot of rain over the summer and during a couple of sampling session the lambs were wet and I did not take their weights. In August I started to pull ewe lambs out into a separate group.  I did not want to waste grain and get them too fat.  Their weights leveled off and some declined.

On Sept.3 I was becoming concerned for the health of the ewe lambs that were left because of the rise in parasite numbers.  Four developed evidence of bottle jaw.  As they were from different groups I would surmise that they had particularly low natural resistance to H. Contortus.  Because of the evidence of the effectiveness of the garlic juice I treated those individuals with garlic juice on Sept 3. I treated all of the ewe lambs with the garlic on Sept. 9 and they were all tested on Sept. 12.  All lambs showed a decline of egg loads after the final garlic treatment.  All the ram lambs had been sold.

One of the most important results of this experiment is my own heightened awareness and understanding of parasite life cycles and the importance of very careful management of pasture in successful growth of organic lambs.




The most significant parasitic threat to lambs is Haemonchus Contortus.  Here in the Northeast where there is quite a long period of winter and frequent frost between the end of September and the beginning of May, natural conditions determine the extent of survival of the parasites on the pasture.  Pasture and contact with the soil is a critical portion of this parasite’s five-stage life cycle.  Understanding this parasite’s life cycle is essential to mounting an effective preventative management strategy.  Unfortunately there are gaps in our knowledge. 


Simplified Life Cycle of Haemonchus Contortus (Strongylid Nemotode)

Eggs are shed in the feces of the ewes in the morula stage of development by parasites that are in the fifth or adult stage and attached to the sheep’s abomasum.  This occurs when external conditions are favorable.

Individual sheep have widely varied infections that are due to inherited and acquired resistance to parasites and other factors including age, exposure, nutrition, stress, arrested development (hypobiosis), and PPR (peri-parturant relaxation of hypobiosis at lambing).  I am unclear about whether PPR occurs when the ewes lamb in Feb. & March when barn temperatures are below freezing.  It is apparent that these eggs are the ones that must survive to infect the lambs.  My data suggests that lambs were not infected from the winter bedding pack and only developed infections after being on pasture for over three weeks.  The greatest rise in infection did not occur until almost 12 weeks on pasture.  This infection is apparently the result of larvae that hatch from eggs that survive on the pasture over winter.

First stage Larvae develop from eggs and hatch in a day or two to feed on microorganisms in the feces.  After a molt, second stage larvae also feed on microorganisms but they must have contact with soil and favorable conditions. (warm and wet) The average length of this stage is about 20 days.  Some eggs appear to be able to survive in hypobiosis on the pasture for over a year.  This means that one winter is not enough to completely clean a pasture. 

Winter lambing on a bedding pack does not provide favorable conditions for larvae development.  This also explains why my lambs did not exhibit any infection in May.

The second stage molt is started but not completed in the external environment so the infective third stage larva remains encased in the cuticle of the second stage until it is ingested by a sheep.  At this stage the larvae are most vulnerable to environmental extremes and most dangerous to lambs grazing.  These larvae climb up on the grasses in warm wet conditions of dew or rain.  They die from exposure to dry and hot or cold conditions.

The sheath is cast off in the abomasums of the sheep and the now parasitic third stage larva attach to the sheep’s abomasums and suck blood.  Next they under go a molt to the fourth stage.  This stage has not been reproduced as yet in the laboratory.


The fourth stage sooner or later molts to the fifth or adult reproductive stage depending on whether or not it enters a period of arrested development. (Hypobiosis) Ewes carry fourth stage parasites in their abomasums that survive in hypobiosis through the winter to shed eggs again in the spring on pasture.  If lambs are not grazed with ewes or on the same ground they will not be exposed to as high a rate of infective larvae.

During hypobiosis the sheep remains infected but the parasites are inactive and not reproducing.  It appears that hypobiotic parasites are able to withstand the use of anthelmetics.  It is unknown what exactly triggers the hypobiosis or how long the parasites can survive in this state.

H. Contortus female may pass as many as 10,000 eggs per day under favorable conditions making it possible for one sheep to pass as many as 30,000,000 eggs per day. 

Understanding this parasite’s life cycle and the influence that the weather conditions have on it are important for parasite control and management.  If the average period that first stage larvae need to molt into their second stage is 20 days, then it would be wise to rotate pasture every two weeks and not revisit a pasture for at least 30 days.


My Management Calendar

September 1st Ewes are turned into second crop for flushing.


Rams are introduced to the flock September 15 and removed on November 1st. 


Ewes are brought in off pasture and fed hay November 15 (or when the ground freezes and they begin to need hay and water).


December 20th Ewes start to get supplemental organic grain gradually increasing from 1/10th  of a pound to ½ pound over a week.  Thin ewes are sorted out into a separate group and given more grain.


Sheep are shorn in January. Six or seven lambing pens (4x4’) are set up.


Lambs start to be born February 5th .  Ewes lamb in the flock group and are moved into a lambing pen for 2 to 3 days.  Then moved into a pen with up to 5 other ewes with lambs for a few days before joining the larger group of lambed ewes.  Lambs are given free choice grain in a creep feeder.


All lambs are born by April 1st .  Ewes with February lambs are taken off grain and only fed hay.


April 25th  to 30th Feb. and early March lambs are weaned.  Ewes are removed and dried off. 


May 10th Ewes are moved out to pasture.  Weaned Lambs are moved into dry lot with free choice grain, hay, and access to winter cleaned pasture.  Lamb’s pasture access is moved every 10 days.


Recent Developments

Through my work on this project, I had the opportunity to work with one of Dr. Tom Settlemire’s interns, Elizabeth McCain.  She had been working with Dr. Settlemire on the Katahdin Sheep Project and had been certified and enthused by the FAMACHA© System.  This is a system that uses a visual observation of the redness of the interior of the eyelid using a specially developed eye color chart to determine the degree of infection due to Haemonchus Contortus.  H. Contortus being a blood sucking parasite causes anemia that is observable in the color of the inner eyelid tissue.  This system was developed in Africa where parasites have developed severe resistance to anthelmetics.

I had the opportunity to attend a training session for the use of the FAMACHA system this fall and am excited by how simple it is for determining infections as opposed to the fecal samples.



Taking and testing individual fecal samples is time consuming.  I got to the point where I could do 12 lambs in about an hour and a half by myself.  That includes penning, weighing, preparing the lab equipment, collecting samples and recording sample and ear tag numbers.  The lab work for 12 samples of preparing the slides, examining with a microscope, calculating, and entering results took about another hour and a half.  That works out to about 15 minutes per lamb per sampling session.  Starting with 51 lambs was a bit daunting.

My Vet. Clinic charges $12.00/ sample for lab work and did not identify the parasites or count them.  Being able to monitor parasite loads economically and conveniently is an important portion of best management in raising organic lambs.

It is exciting to have the FAMACHA System available as it is much more efficient and cost effective.  The Katahdin Sheep Project has determined that genetic resistance to H. Contortus can be monitored using this technique.

Learning which sheep are naturally resistant to parasites and breeding for that trait should reduce the need for treatments.

The use of Garlic Juice is less much expensive than conventional Ivermectin or the other organic treatments I used in the experiment.  One gallon of Garlic Barrier cost $45.00 plus $9.19 in shipping from the manufacturer. (see sources)  The dosage that I have been using is one teaspoon per sheep. 




I would like to pursue this research further and use the FAMACHA system to monitor parasite infection and then take and count fecal samples of lambs that exhibited infections and treat them with Garlic Juice at different dosages.  I would also be interested in seeing if the data supports the idea of natural genetic resistance. (I have submitted a SARE grant proposal for 2004)  There continues to be the possibility that strains of H.Contortus could become immune to the garlic treatment.  Selection for natural resistance and careful treatment and culling of susceptible lambs is a long term strategy that I recommend. 




I will use garlic juice in treating my flock for parasites.  I dosed all my sheep when I brought them into the barn for the winter.  I will treat them at lambing to reduce the possibility of PPR (peri-parturant relaxation of hypobiosis of H. Contortus at lambing). 




I made a short presentation at the Katahdin Hair Sheep International Gathering.


I intend to submit articles to the MOFGA newspaper, The Maine Sheep Breeders Assn Newsletter, and the SHEPHERD Magazine .  I am also sending copies to the Maine and New Hampshire Cooperative Extension Service.  I will gladly discuss my results with anyone interested and demonstrate the sampling and Lab. procedures.  I plan to schedule a field day next summer at this farm and would like to collaborate with Dr. Settlemire to hold a FAMACHA Training Session.


Project Leader:   Jean Noon

78 Sunset Road

Springvale, Maine 04083







A Controlled Experiment To Measure The Effectiveness On Lambs Of Wormers That Conform To The New Organic Standards.  FNE03-482




Garlic Research Labs Inc.

624 Ruberta Avenue

Glendale, CA. 91201

1-800-424-7990  FAX 1-818-247-9828


Farmstead Health Supply

P.O.BOX 985

Hillsborough, N.C. 27278


Crystal Creek Services

Leiterman & Associates Inc.

N9466 Lakeside Road

Trego, WI 54888

1-888-376-6777  Fax 715-466-5842


Modified McMaster Egg Counting Technique(green Line slides)

Olympic Equine Products (Advanced Equine Products)

5004 228th Ave S.E.

Issaquah, WA 98207

425-391-1169  For counting the eggs on the green line slides I found it necessary to purchase a binocular microscope with a moveable platform.  I was able to find one at this site for $329.95 that works really well.  (Purchased with my own funds)

The Microscope Store
316 Windy Pines Lane
Rocky Mount, Virginia 24151
Toll Free: 1-877-409-3556 Telephone: 540-489-4785
FAX: 540-489-4785