High tannin grain sorghum as a possible natural anthelmintic for sheep and goats

2008 Annual Report for LNE05-232

Project Type: Research and Education
Funds awarded in 2005: $100,000.00
Projected End Date: 12/31/2009
Matching Federal Funds: $52,161.00
Region: Northeast
State: Maryland
Project Leader:
Niki Whitley
UMES - Maryland Cooperative Extension

High tannin grain sorghum as a possible natural anthelmintic for sheep and goats


The objectives of the proposed project are to determine the effectiveness of high-tannin grain sorghum as a natural anthelmintic for small ruminants and provide workshops to demonstrate use of the sorghum and methods for determining need for anthelminitic treatment (FAMACHA©, fecal egg counting). In year one, working with the National Grain Sorghum Producers (SGSP), at least five sorghum varieties will be tested for tannin levels and levels will be compared with serecia lespedeza (has high tannin and decreases parasite fecal egg counts in goats). In year two, at UMES, 60 crossbred hair sheep lambs and 60 Boer crossbred goat kids will be artificially (part 1) or naturally infected with parasites (part 2) and will be fed diets containing high tannin (based on year 1 results) or low tannin grain sorghum (30/species/treatment) and parasitism monitored. Workshops for producers will be held to demonstrate and teach the parasite monitoring techniques (FAMACHA©-an eye color chart- and fecal egg counting) and follow-up meetings held to determine how many producers implement one. In year 3, on-farm projects will be conducted in MD with cooperation from the Lower Shore Goat and Sheep Producers Association and in PA through PASA and follow-up will occur through phone calls and interviews with farmers. Products of this project will include the development and demonstration of a natural dewormer for small ruminants using University and producer-led research and the development of a new market for high-tannin grain sorghum, thus helping to sustain two different agricultural areas. A fact sheet and newsletter articles will be published. Of the 60 participating farmers, 20 will decrease chemical dewormer use through the use of grain sorghum as a natural dewormer and/or incorporation of the use of FAMACHA© or fecal egg counting. In year 4, an impact evaluation survey was developed and contact list compilation started; a manuscript publication was developed and workshop survey evaluations were summarized.

Objectives/Performance Targets

Of the 60 small ruminant producers engaged in this SARE project, 20 will decrease chemical dewormer use through the use of grain sorghum as a natural dewormer and/or incorporation of the use of FAMACHA© or fecal egg counting.


The milestones are 1) 100 interested small ruminant producers will respond to flyers to gain understanding about parasite control through integrated methods, including potential natural dewormers 2) 60 producers will attend first workshop 3) 40 producers will attend second or third workshop 4) 20 producers will decrease chemical dewormer use through natural dewormers and using the FAMACHA© eye-lid color chart or fecal egg counting (farm visits, phone calls, interviews)
Before the project even started (due to a newsletter article about the plans for the project), 2 producers have emailed to ask questions about the newsletter article describing the project plans. In addition, 3-4 producers have called or stopped me in public to ask about hosting another parasite workshop. Over 200 interested producers were invited to a general small ruminant parasite control session as well as specific FAMACHA©/Integrated Parasite management training. Over 150 registered and at least 100 attended. Surveys are planned to determine how many producers have decreased chemical dewormer use. Workshops were held and newsletters written on results of four research projects.

Impacts and Contributions/Outcomes

Eight varieties of grain sorghum were analyzed for tannin content by Lloyd Rooney at Texas A&M University, a known leader in the area of milo tannin research. Three varieties were chosen for planting for the animal studies summer of Year 1 and were obtained in the Fall for research studies in the following Spring/Summer. The National Grain Sorghum Growers cooperative Grain Sorghum Partners, Inc. grew and donated the high tannin grain sorghum for the trials.

Preliminary goat study, Year 1: A high tannin variety of sorghum (one that had been tested) had been stored by the National Grain Sorghum Growers cooperative Grain Sorghum Partners, Inc. and was shipped to UMES for a preliminary goat study. A low tannin variety had been grown at UMES for a Cooperative Extension demonstration plot and had been stored at UMES. A local producer had a bad parasite problem and offered to skip a deworming so the animals would be naturally infected and then would sell them to UMES for the study. Only 16 of the 31 goats purchased could be used (the others were too anemic and had to be dewormed right away). Goats were placed on a concrete slatted floor (to keep re-infection from occurring) and half were fed a diet of high tannin sorghum with a protein supplement and alfalfa pellets for fiber while the other half were fed a diet of low tannin sorghum with a similar mixture of other ingredients. Body weights, fecal egg counts, FAMACHA© scores and packed cell volume (PCV-to indicate true anemia) were collected on the goats weekly for 3 weeks. Because almost all of the goats eventually had to be dewormed, it was concluded that this grain sorghum variety or feeding strategy did not seem to work. However, everyone involved in the discussions, including the producers, indicated that more research is needed since only one level in the diet and only one variety was used. A couple of producers asked about adding a second natural dewormer if possible (such as garlic) in a controlled trial at UMES.

We learned in this preliminary study that FAMACHA© and PCV were not 100% related in these goats (PCV was very good for some animals with a 4 or 5 FAMACHA© every week), and thus we used PCV to determine deworming schedule for the entire study instead of FAMACHA©. Because there are no cases of nice pink eyelids having low PCV and the opposite is also rare, FAMACHA© is still an excellent tool for producers and will still be stressed as one of the best methods for “fighting” parasite resistance to dewormers. Indeed, we did note an overall negative relationship between FAMACHA© score and PCV, as expected. It is well documented that the FAMACHA© system definitely reduces the amount of chemical dewormers used, which is better for the environment and is more economical for producers as well.

In Year 1, pasture shelters and pens were put in place for research projects and breeding for research animals. Some animals that were purchased from the producer in the first Year were very wormy so they were kept for breeding for animals for this research so that we could be more confident of getting wormy offspring animals for testing.

Boer and Boer crossbred goats were used in two studies in Year 2. Twenty-four animals were housed in individual pens, and for the first experiment in Year 2, as per collaborators advice, animals were removed from pasture when fecal egg counts indicated infestation and adult worms were allowed to “mature” in the animal for 21 days prior to the start of the feeding comparisons. They were fed a diet containing some low tanning milo as a transition feed so that after 21 days, as for the preliminary experiment, diets were with either high (treatment) or low tannin milo (control) were fed. Fecal egg counts and PCV were measured weekly beginning when animals were placed into the pens from pasture. Animals with PCV below 15% were dewormed. Gross eyelid color as a sign of parasitism was monitored between PCV testing periods. Fecal eggs counts decreased for all animals regardless of type of milo in the feed 1 week after treatment feeding began and remained steady until around day 21, when counts began to increase again. It is thought that a possible “self-cure” as has been documented by other small ruminant parasite researchers may have occurred.

In the second Year 2 study, conducted similarly to the preliminary study but with animals in individual pens, again, there was no influence of treatment on fecal egg counts or packed cell volume. Three different varieties of high-tannin grain sorghum were tested at a high level in the feed, and no effects on gastrointestinal parasite infection have been found.
Year 3 was a very dry year and very few goats exhibited signs of parasitism at UMES or on producer farms. In addition, because the UMES farm studies indicated no influence of high tannin grain sorghum on internal parasites, the producer advisory council indicated that they did not see any reason to conduct on-farm studies. Instead, they continued to express interest in testing other potential dewormers. After presenting the research at the Southern Section ASAS (Animal Science) meetings in the Sheep and Goat Section, the PI was asked to join a group of scientists/veterinarians and extension personnel (Southern Consortium for Small Ruminant Parasite Control; www.scsrpc.org) studying alternative, holtistic methods for small ruminant parasite control. The group consists of forage experts, biochemists/chemists, animal scientists, geneticists and extension educators from the U.S. and other countries, including South Africa. Part of the efforts of this group includes analyzing tannin levels/types in plants to determine those with potential in fighting worms. The PI, Dr. Whitley, had requested that members of this group run tannin levels on the milo and some sericea lespedeza in Year 1 and 2, but were not able to do so until Year 3. The levels of tannin in all species of the high tannin milo/grain sorghum were significantly less than that found in sericea lespedeza. However, members of the group still felt that amounts/levels may not be as important as “type” and may still choose to use milo extracts for in vitro larval development assays.

Overall, in SCSRPC group meetings, it was decided that it is possible that the tannin in milo (grain sorghum) may not the same type of condensed tannin that is thought to decrease fecal egg counts when fed via sources such as serecia lespedeza. After seeing these results and through discussions with Dr. Whitley, the farmer/producer advisory council (Lower Shore Goat and Sheep Producers Association) would like to see alternative possible non-chemical dewormers tested and have suggested a commercial “herbal” dewormer, garlic and/or tobacco. The SCSRPC group (which included collaborators listed in this and earlier reports) found a method to pellet sericea lespedeza (SLP) that still allowed for effective reduction in fecal egg counts and requested that Dr. Whitley conduct a study involving the SLP. After consulting the advisory council of producers, it was agreed the study was warranted. The project was planned as a comparative treatment (milo, controls and SLP). However, the few animals available because of low parasite infestation only allowed for a small preliminary study for the SLP (since it showed greater promise than the grain sorghum). In the study, 9-13 goats per treatment (total 45 goats allotted to treatment to account for weight, sex and FEC) were used to look at effects of 0 (control), 20, 40 or 60% SLP on PCV and FEC in young growing kids naturally infected (from pasture grazing) with worms. Diets were mixed to have similar protein and energy levels and all goats had been supplemented with a comparable grain diet while on pasture. There were no differences in PCV and FEC due to treatment, however, after culturing feces to hatch the eggs and speciate the larva, it was noted that the control goats had the highest percentage of Haemonchus contortus (blood sucking worm) larva at 43% with 20, 40 and 60% being 39%, 35% and 31%, respectively. Although the SLP did not seem to influence FEC and PCV, the animals were not heavily parasitized by H. contortus (the primary problem parasite in small ruminants) as noted by normal FAMACHA© scores and PCV but it seemed that SLP may have specifically decreased numbers of H. contortus in the animals. So, if the primary worm load had been of this parasite as is seen in normal weather years, the sericea lespedeza pellets may have been a very effective alternative parasite control method. Therefore, more research is needed for this and other potential natural dewormers.

Year 4 (no-cost extension, 2008-2009) – The SCSRPC group was interested in a survey being developed to determine the impact of this study and associated FAMACHA trainings. Therefore, the PI is working with SCSRPC to coordinate impact of FAMACHA trainings not only for MD but for other States as well. Re-evaluation of the data for the research in preparation for manuscript publication indicated possible slight effects of one variety of grain sorghum that may be further evaluated using different funding sources. At a general small ruminant parasite workshop in New Jersey (120 registered), 56 people raising an average of 8.22 animals each responded to a survey about problems with internal parasites. Not surprisingly for persons with small flocks, only 37% indicated a problem with parasites and all (plus some that said no problem for a total of 43.2%) indicated that the problem was not bad- that they dewormed every 8-12 weeks and the dewormers worked. Nearly all respondents (97.5%) indicated that they would use a non-chemical dewormer if it were proven to work. A FAMACHA© workshop held in PA was evaluated for short term impact. Participants returning evaluation instruments (9) indicated an increased knowledge of 35.6% in understanding that Haemonchus contortus is the number one problem parasite and its primary symptom is anemia, which dewormer is used for tapeworms, how to use eye lid color scoring to decrease dewormer use and that goats need a higher dose of dewormers than other species. Integrated parasite management discussions with the Lower Shore Goat and Sheep Producers Association included a survey of producers as well. The participants returning the survey (5) indicated that 100% were already either using FAMACHA© or simple eye lid color evaluation to determine when to deworm their animals. However, results indicated that 2 of the 5 (40%) did not feel they had a problem with parasites on their farm. Follow-up with those producers has since determined that they had animal losses to parasites since the meeting, indicating that they were just not previously aware of the problem. All respondents indicated that they were interested in non-chemical dewormers, were interested in the results of this project and learned more about NE SARE through the PI of this project. An overall impact evaluation survey has been started. So far, data is being collected from FAMACHA trainers throughout the U.S. Data will be collected by State so a Maryland report can be provided.

Project information has been reported in the Maryland Sheep and Goat newsletter (Wild & Wooly) as well as in presentations at 5 producer meetings and a meeting of the SCSRPC group as well as a meeting of the recently formed SCC-081 research exchange group. A scientific abstract has been published and a presentation given at professional meetings (included several Extension personnel from across the US in the audience). The information from the research projects has recently been submitted as a manuscript to a peer-reviewed journal (Veterinary Parasitology).There continues to be much interest in natural dewormers for goats and sheep. The input of the advisory council of producers indicating a great interest in natural or alternative dewormers had a great impact, resulting in potential research into alternative natural dewormers such as garlic and pumpkin and papaya seed at UMES and other Universities (Delaware State University).


Susan Schoenian

Area Agent
Maryland Cooperative Extension
Keedysville Rd
Keedysville, MD
Website: www.sheepandgoat.com
Harry Taylor

Backbone Rd
Trigg Hall
Princess Anne, MD 21853
Office Phone: 4106514486
Michelle Gauger

Heather House