Final Report for SW12-114

Project Type: Research and Education
Funds awarded in 2012: $37,125.00
Projected End Date: 12/31/2015
Region: Western
State: Hawaii
Principal Investigator:
Matthew Stevenson
University of Hawaii
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Project Information


Reducing input costs ranks as a high priority among Hawaii farmers and ranchers owing to geographic isolation and associated high shipping costs. Some ranches have applied multi-species stocking as a lower cost alternative to chemical weed control. One ranch has further modified multi-species stocking by implementing a training method to create social bonds between species to aid in herding and improve pasture use efficiency. Modifying livestock behavior to meet management needs more economically may result in secondary effects.

This study attempted to quantify any effects of eating weeds on parasite burden in goats. While normally readily eaten, goats did not eat enough of Schinus terebinthifolius or Indigoferra suffruticosa offered to note any causal relationships, though there is evidence warranting further study of this approach should the intake issue get resolved. Also, intake of weeds at other sites dropped so much that we could not quantify in situ pasture use effects between weed eating and non-trained livestock as originally intended. We observed significant differences in pasture use by bonded and non-bonded groups of cattle, sheep, and goats, with bonded groups remaining considerably closer together throughout a two-week study period. While we did not collect strong enough information to create management recommendations for these approaches, rancher feedback from outreach efforts were favorable to the methods and concepts. Some ranches have adopted the idea of using forages to augment worm control programs in response to a loss in pharmaceutical anthelmintic efficiency. Future studies should reevaluate Schinus as a potential aid in controlling worms and why it is readily eaten by livestock in certain situations but not others. An in-depth economic analysis should evaluate livestock bonding as a labor or capital investment technique as compared to running separate herds. Livestock bonding may also result in transmission of foraging strategies across species and warrants further evaluation from a pasture use efficiency perspective.

Project Objectives:

  1. Quantify effects of Christmasberry (Schinus terebinthifolius) and indigo (Indigoferra suffruticosa) during wet and dry seasons on internal parasite loads of livestock. Performance Target: Aim to have trials completed by month 12 following project start on all five ranches.
  2. Quantify in situ pasture use relative to parasite loads and weed forage quality in animals trained to eat weeds and in untrained animals. Performance Target: Complete at least two observation periods per ranch by end of month 12 following project start.
  3. Quantify any differences in pasture use by bonded animals compared to non-bonded animals. Performance Target: Complete at least two observation periods at Haleakala Ranch by end of month 12 following project start.
  4. Generate management recommendations for ranchers or describe strengths and weaknesses of behavior-based management programs based on analysis. Performance Target: Publish results and recommendations by month 18 following start. The second year of the project will focus on finishing analysis and outreach efforts through presenting at various producer and professional meetings and field days.


Ranchers and farmers identified increasing locally grown grass-fed beef and reducing farm inputs among the types of research, education, and production improvement they need over the next 5-10 years at the 2008 Hawaii Sub-regional Western SARE conference. Pasture weeds hamper ranch profitability by reducing the amount of useable forage and imposing high management costs. To reduce or eliminate expensive inputs such as herbicide application, some cattle ranchers in Hawaii are turning to multi-species stocking to leverage differences in foraging preferences to control weeds. A handful of innovative ranchers are implementing other principles of behavior-based management developed by the Behavioral Education for Human, Animal, Vegetation, and Ecosystem Management (BEHAVE) Network to improve weed management even further. Specifically, a group of ranchers are involved in a 2011 Western SARE funded Producer + Professional project titled, “Training Livestock to Eat Weeds in the Tropical Pacific and Evaluating the Effects on Meat Quality for Stronger Ranch Profits” to evaluate livestock training methods for weed management in the tropics. 

Ranchers on the 2011 Producer + Professional project, as well as others with multiple species grazing for weed management experience, believe some plant species may help keep internal parasite levels low. Cattle in particular appear to graze certain weeds inconsistently, and ranchers have hypothesized that increased parasite burden leads to increased use of those weeds. Parasite resistance to anthelmintic drugs is a growing problem especially in the tropics and sub-tropics leading to serious impacts on ranch profitability (Min and Hart 2003). Reports from the tropics and elsewhere show evidence for anthelmintic properties of some plants high in condensed tannins that are available in Hawaii (Sokerya et al. 2010, Min et al. 2004, Min and Hart 2003). If currently underused pasture plants can be identified as having effective anthelmintic qualities, through grazing management of trained animals ranchers can reduce use of pharmaceutical anthelmintics thereby protecting drug efficacy and potentially lowering input costs.

Haleakala Ranch, a participant on a 2011 Western SARE Producer + Professional project as well as this study, is also experimenting with creating interspecies bonds based on USDA Agricultural Research Service work for greater ease in herding multiple species and to a lesser extent predator protection (Anderson et al. 1994). Haleakala Ranch has been using small numbers of animals to bond sheep to cattle and goats to sheep. “Bonded” species herd together as a unit as opposed to separate groups requiring more labor time to move between paddocks or additional temporary fencing. In addition, non-bonded species using the same paddock potentially limit their pasture use in response to the presence of the other species. There is limited published data on in situ paddock scale spatial use of bonded multi-species herds versus non-bonded individuals.

What, when, where, and why an animal chooses to eat a particular plant or plant part is a complex interaction of individual experience, stocking density, distance to water or cover, nutritional and health status of the animal, relative concentration of digestible nutrients and anti-quality compounds in the plant, and the quantity and variety of alternative forage choices on hand (Villalba and Provenza 2009, Provenza et al. 2007, Ganskopp and Bohnert 2006, Launchbaugh and Howery 2005, Laca and Demment 1996). Changing one aspect of an animal’s behavior by training it to meet one management objective, such as eating weeds or interspecies herding, potentially alters the complex dynamics of foraging behavior and overall pasture use. 


  1. Anderson, D., K. Havstad, W. Shupe, R. Libeau, J. Smith, and L. Murray. 1994. Benefits and Costs in Controlling Sheep Bonded to Cattle Without Wire Fencing. Small Ruminant Research 14(1):1-8.
  2. Ganskopp, D. and D. Bohnert. 2006. Do Pasture-Scale Nutritional Patterns Affect Cattle Distribution on Rangelands? Journal of Rangeland Ecology & Management 59(2):189-196.
  3. Laca, E. and D. Demment. 1996. Foraging Strategies of Grazing Animals. In: Hodgson, J. and A. Illius (eds), The Ecology and Management of Grazing Systems. CAB International, Oxford, UK, pp. 137-158.
  4. Launchbaugh, K. and L. Howery. 2005. Understanding Landscape Use Patterns of Livestock as a Consequence of Foraging Behavior. Journal of Rangeland Ecology & Management 58(2):99-108.
  5. Min, B.R. and S.P. Hart. 2003. Tannins for Suppression of Internal Parasites. Journal of Animal Science 81(E.Suppl.2):E102-E109.
  6. Min, B.R., W.E. Pomroy, S.P. Hart, T. Sahlu. 2004. The Effect of Short-Term Consumption of a Forage Containing Condensed Tannins on Gastro-Intestinal Nematode Parasite Infections in Grazing Wether Goats. Small Ruminant Research 51:279-283.
  7. Provenza, F., J. Villalba, J. Haskell, J. MacAdam, T. Griggs, and R. Wiedmeier. 2007. The Value to Herbivores of Plant Physical and Chemical Diversity in Time and Space. Crop Science 47(1):382-398.
  8. Sokerya, S., C. Phanchadcharam, M. Suy, and J. Hoglund. 2010. Effects of Ensiled Cassava (Manihot esculenta) Foliage Compared to a Soybean Meal Supplement on Gastrointestinal Nematode Infections in Goats. Livestock Research for Rural Development. Volume 22, Article 115. Accessed May 26, 2011 at
  9. Villalba, J. and F. Provenza. 2009. Learning and Dietary Choice in Herbivores. Journal of Rangeland Ecology & Management 62(5):399-406.


Click linked name(s) to expand
  • Randall Cremer
  • Greg Friel
  • Lani Petrie
  • Fred Provenza
  • Tom Runyan
  • Mark Thorne
  • Juan Villalba
  • Duke Wellington


Materials and methods:

Objective 1 – Effects of pasture plants on internal parasite loads.

Project Site: University of Hawaii College of Tropical Agriculture and Human Resources (CTAHR) Kauai Agricultural Research Center (KARC), Wailua.

Materials and Design: From July to August 2013, 32 goats weighing on average 18kg were borrowed from Tony’s Goats (Kapaa, Kauai) for this trial and located on a two-acre napier grass (Pennisetum purpureum) dominated pasture at KARC. The were treated with 4mL of albendazole (Valbazen, Zoetis – Florham Park, NJ) then acclimatized for two weeks and rotated every 5 – 7 days through four paddocks. During this period nine goats were pulled from the project owing to health reasons such as heavy parasite load and foot problems. We established three treatment groups: Control (seven goats), Christmasberry Supplement (eight goats), and Indigo Supplement (eight goats). For supplementation, Indigoferra was collected from Haupu Ranch near Nawiliwili Harbor, and Schinus was collected from the roadside near Puhi. The control supplement was at first a commercial feed of similar quality to the other treatment groups, but this was changed to napier grass on day five of the trial owing to the fact that the other groups were not eating much of their supplements. These supplements were promptly refrigerated and fresh samples were collected every other day. Eggs per gram (EPG) of strongyloid type eggs was determined for each goat by a Modified McMaster method before first supplementation to establish a baseline infection rate. Goats were also weighed before and after the two-week feeding period. Initially, goats were penned overnight and offered the supplements for two hours before removing and weighing refusals and releasing goats to pasture for the remainder of the day. Fecal egg counts were again determined after seven days. As very little of the supplements were being eaten in the two hour period, for the final week supplements were left out in feed bins until evening. This increased intake, but overall intake remained low.

Objective 2 – in situ observations of trained compared to untrained animals.

Project Sites: Jurassic Kahili Ranch (Kauai), Tom’s Goats (Kauai), Rocking W Ranch (Kauai), Haleakala Ranch (Maui), and Kapapala Ranch (Hawaii).

Materials and Design: A representative pasture was to be selected for analysis that had populations of target weed species. A mixed herd with trained and untrained animals was to have two animals from each group randomly selected to carry a GPS collar capable of recording one location every five minutes. If the pasture was grazed by a trained group alone followed or preceded by an untrained group, four animals were to be randomly selected to be collared when they went in the representative pasture. GPS collars were to collect data for up to two weeks depending on ranch grazing management for the sample area. Parasite burden of each animal selected was to be estimated by fecal egg count at the beginning and end of the two-week period as well as nutritional status by fecal sample analysis. Each plant community represented in the pasture was to be sampled for nutritional quality based on four composite forage samples. Samples were to be collected once in the dry season and once in the wet season to account for climatic variation. 

Objective 3 – Comparing pasture use of bonded versus non-bonded animals.

Project Site: Haleakala Ranch (Maui).

Materials and Design: To form social bonds between species, recently weaned lambs were placed in an adjacent but separate pen from yearling steers and heifers and fed for 3-5 days. The pens were then combined and feeding in confinement continued. After threee days of confinement together, cattle and sheep were turned out together to a three-acre paddock and given supplemental feed once a day in the adjoining training pen. Bonding was deemed adequate by the participating ranch manager when sheep and cattle grouped together when herded with dogs and there were no signs of aggression from cattle toward sheep. Goats were introduced to the group and herded with the sheep without additional efforts beyond the once a day supplemental feeding in the small training pen.

We deployed Lotek Wireless Global Positioning System (GPS) collars on two goats, two sheep, and two cattle that were part of this bonded group in December 2013 (Figure 1). We collected location data for two weeks on a five-minute cycle from 0600 to 2100, and a 30-minute cycle from 2100 to 0600. Cattle, sheep, and goats not trained as a bonded group were similarly deployed with GPS collars in the same approximately 50-acre paddock for a two week period from April to May, 2014.

Once downloaded from collars, latitude and longitude data for animal locations were synched in time for both bonded and non-bonded groups. For analysis, we estimated square meters occupied by the group at each time point by using the maximum distance between individual animals as the diameter of a circle. We also looked at the mean linear distance between animals per group. The first and last two hours of recorded data points were not included as this represented handling of animals. Also, data points where latitude and longitude could not be fixed by the collars of one or more animals were not included.

Objective 4 – Management recommendations.

The primary tool for outreach with findings or recommendations was via professional and producer meeting presentations. Secondary outreach tools would be traditional University of Hawaii Extension Publications as well as brief, less than 5-minute, videos for online viewing.

Research results and discussion:

All statistical analyses presented were derived using JMP 12 software (SAS Inc., Cary, NC).

Objective 1.

The penned goats ate very little of the supplements offered, from 2.2 – 4.4% of their estimated daily dry matter intake across treatment groups (Table 1). Intake increased after leaving supplements available for the entire 12 – 14 hour grazing period.

Figure 2 shows a nominal decline in mean eggs per gram (EPG) determined by treatment group. Given the small amount of supplements eaten, any causal relationships drawn would be spurious. Furthermore, all groups maintained levels higher than 1,000 EPG which is often considered a point when to treat with anthelmintics. Each group showed only nominal changes in weight over the two-week period. 

We attempted to repeat the study and make efforts to overcome the low intake levels but were unable to acquire enough animals. The original collaborator liquidated the business and livestock to move, and most other herds are under 50 head making recruitment of new collaborators difficult. If future work is funded, we may use study sites on other islands where there are considerably larger herds.

Objective 2.

An inability to effectively train animals onto weeds made pursuit of this objective untenable. The intent was to dovetail this objective with animals trained to eat weeds in a separate Western SARE Producer + Professional project. However, three of the collaborating ranches had sold the trained animals for various management purposes, and one operation ceased operations and liquidated its livestock. With a no-cost extension, we trained new groups onto weeds, but once out of training pens, weed intake ceased in two cases resulting in no treatments to pursue.

Objective 3.

Bonded and non-bonded groups showed very clear differences in how they used a paddock. The bonded group used much smaller square meters of area at any given observation time. In other words, all animals of the bonded group were found closer together at any given time compared to the non-bonded group. In contrast, the non-bonded group animals consistently maintained very large linear distances from other species in the group. In the case of the non-bonded goats, they escaped from the study paddock and made no attempts to re-group with the other animals. GPS collar data are summarized in Table 2 and Table 3.

Figure 3 is a graphical example of a randomly selected hour of GPS collar data from the bonded group. The animals appear to have arranged themselves in a typical pattern of a bonded group as observed by the collaborating ranch manager: When undisturbed, all animals in the group remain relatively close together but tend to segregate by species (Figure 4). Once herding dogs are introduced into a pasture, the separate sub-groups of species form one herd. Figure 5 shows an hour of data from 800 – 0900 from a randomly selected date during observation of the non-bonded group. The collaborating ranch manager noted that the goats in this group tended to remain noticeably separate from the sheep and cattle.

Research conclusions:

Alternative Worm Control

While our results did not show a strong effect of Schinus or Indigoferra on worm egg counts, rancher feedback from outreach efforts showed considerable interest in this approach toward worm control. Small ruminant producers were very interested in any level of control owing to marked worm resistance to anthelmintics. Cattle producers presented with this information indicated that their knowledge of worms as a problem in their species had increased and would also reevaluate their anthelmintic problems. More generally, as part of the outreach efforts, some ranchers indicated changing their worm management even if not intending to adopt alternative anthelmintics at this time. Simply changing their anthelmintic rotation or treating on an as needed basis versus on a fixed schedule to reduce resistance was stated in some form by participants in each of the workshop series.

Livestock Bonding

Without exception, ranchers presented with the details of livestock bonding indicated an increase in knowledge related to the principles and application of this approach to multi-species management. The data confirmed the collaborating ranch manager’s observation that bonded animals spend more time in close proximity to each other. Consequently, he believes foraging behaviors are more readily transmitted across species as opposed to non-bonded groups.

Participation Summary

Educational & Outreach Activities

Participation Summary

Education/outreach description:

Professional and Industry Group Meetings

The PI presented a 15-minute talk on the project background and initial findings to an audience of 15 ranchers at the Maui Cattlemen’s Association annual meeting on December 15, 2012. A ranch manager from Haleakala Ranch was present and led much of the question and answer session following the presentation.

On September 26, 2013, the PI gave a 20-minute talk on the project to an Extension professional workshop held at the Poamoho Experiment Station of the University of Hawaii with about 40 professionals from across the state in attendance. Owing to different groups going to multiple field visit sites immediately after the talk, most participants left before any formal evaluation data could be collected.

On November 8, 2013, the PI presented a 45-minute talk accompanied with slides to the Hawaii Sheep and Goat Association annual meeting attended by 28 people. Post-presentation evaluation data using the SARE form were collected via online survey and are summarized in Figure 6.

From November 15 – 16, 2013, the PI and one collaborating rancher were present at the College of Tropical Agriculture and Human Resources (CTAHR) booth at the Hawaii Cattlemen’s Convention with a looped computer presentation on livestock bonding. In this informal setting, it was difficult to collect formal evaluations, but of the approximately 200 attendees, many visited the booth and asked questions about the project.

On May 3, 2014, the PI presented a 45-minute talk on the project background and results to date as part of a Goat Basics Workshop held at the CTAHR Kauai Agricultural Research and Extension Center reaching 21 small-scale producers.

The PI gave a 20-minute oral presentation on the internal parasite aspect of this project at the Society for Range Management annual meeting on February 5, 2015 in Sacramento, California. Approximately 26 people attended including producers from similar environments in Florida who indicated their interest and support of the project aims and approach. 


An introductory article as well as a brief follow-up article was written for the Kauai Livestock News newsletter circulated among 220+ e-mail recipients in the Fall/Winter 2011 and Spring/Summer 2012 editions respectively.

A draft version of a CTAHR Extension Publication on the background and results of the bonding aspect of this project is in review by the collaborators. The report acknowledges USDA Western SARE as the funding authority and will be available online in perpetuity for no charge.

A brief video on the bonding aspect of this project was presented at the 2013 Hawaii Cattlemen’s Convention. The video is available for free at: At this reporting, the video has received 348 views.

Project Outcomes

Project outcomes:

Alternative Worm Control

Based on the 32 goats used initially in this study, one person could treat all animals with one dose of oral drench albendazole in 45-minutes. At local prices, the cost of this particular product was $0.62 per goat for a total material cost of $19.84 per treatment. Many Hawaii producers treat for worms once a month.

As 9 goats showed clinical signs of internal parasitism within two weeks of treatment and the remainder of the group showed an EPG well over the rate recommending treatment, either a higher dose of albendazole or a more frequent schedule would be required for effective control. Under-dosing or treating with pharmaceuticals every two weeks is not feasible to prevent worm resistance to dewormers. Furthermore, treating above the rate used would be off-label and requires veterinary approval.

In the case of this study, cutting Schinus and Indigoferra to feed 23 to 32 goats took approximately one hour for one person. Assuming a range situation where these plants are available in adequate quantity, animals would have access to these plants as part of their regular rotation and wouldn’t require additional labor.

While the cost of either customary worm control or that of using Schinus or Indigoferra is relatively low, the effectiveness of both methods is rather poor in our conditions. Thus, at least in this case, low cost of ineffective treatments would lead to secondary costs of 28% (9 out of 32) of the herd needing additional treatment within two weeks or let them suffer decreased performance or death.

Livestock Bonding

At this stage, our objectives with this novel approach to herding was to observe and quantify and differences in animal behavior as a result of training. Economic costs or benefits are varied and should be parsed out in future studies. The amount of time required to conduct bonding training depends on individual circumstances such as facilities and number of head. In our case, the collaborating ranch had a pen and training paddock to accommodate mixed groups of up to 50 animals. Preparing and offering feed twice a day took one hour per person total per day during the 6 – 8 days in confinement. Supplemental feeding for once a day over seven days on pasture required 30 minutes per person per day. Approximately two 50-lb bags of feed were used in the initial training for up to eught days at $52/day or $416. Approximately two bags of feed were used over the seven-day supplemental feeding period for a cost of $104. Material costs for the bonding training was $518. The bonds appear to last indefinitely as long as the animals are kept together according to the collaborating rancher.

Farmer Adoption

A 30,000 acre ranch on Hawaii Island now regularly incorporates pastures with Schinus for the purpose of internal parasite control in their goat and cattle herds. The ranch no longer treats adult goats with commercial anthelmintics to prioritize its use with weanlings only. While some losses occurred initially, the ranch attributes a relatively small impact from this change to anthelmintic qualities of Schinus. They note that a browse line on Schinus trees is evident in areas used by cattle and goats.

After being presented with the concept and approach of using forages or plants as alternative dewormers, a commercial meat and dairy goat farm on Kauai began incorporating Mannihot esculenta (cassava) and Carica papaya (papaya) seeds for worm control. While different species than used in this project, these plants have been reported to reduce fecal EPG. This farm uses the FAMACHA system for monitoring parasitism and reports less need for treatment since incorporating these plants for worm control.


Areas needing additional study

Alternative Worm Control

A frustrating aspect of this study was that while goats have been regularly observed in Hawaii eating Schinus and Indigoferra, goats in this study ate very little during the observation period. Future work should address this issue to discover if this refusal was a result of neophobia – the avoidance of unfamiliar feeds by naïve animals, stage of the plants, class of animal, seasonality, secondary compound concentration, negative effects from handling, using animals not accustomed to pen feeding, or some other factor. 

While we could not establish any solid relationships on a group level, our data reveal considerable individual variation in regard to level of infection in goats (Table 4). These data make a compelling case for selectively treating only heavily infected goats and culling goats with consistently high parasite loads regardless of clinical signs. While only one goat readily ate Schinus in this study, it happened to be the one which showed a dramatic decrease in EPG. Our efforts to follow-up on treatment with Schinus unfortunately failed due to logistical issues, but this approach needs further study.

Livestock Bonding

A follow-up study based on our observation that bonded livestock remain in close proximity to each other should evaluate any transmission of foraging strategies between species as compared to their non-bonded counterparts. Follow-up studies could also evaluate effects of bonding in different range and pasture ecotypes such as scrubland versus grassland as well as stocking rate. An economic analysis comparing labor time and facility needs in running bonded herds versus three separate herds is another needed area of future study.

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.