Anthelmintic efficacy of pelleted cranberry leaf powder against experimental Haemonchus contortus infection in lambs

Anthelmintic efficacy of pelleted cranberry leaf powder against experimental Haemonchus contortus infection in lambs

Summary

Gastrointestinal nematode (GIN) infections are a major health concern for small ruminant producers in the Northeast. Anthelmintic resistance can be seen in all species of GIN. In search for alternative methods of GIN control in small ruminants, one of the most promising findings has been the discovery that some forages containing condensed tannins, also called proanthocyanidins (PAC), suppress GIN infection. Cranberries contain high levels of PAC. This project investigated the anthelmintic efficacy of cranberry leaf powder (CLP) additive supplement against an experimental infection of Haemonchus contortus in lambs. This in vivo study examined the anthelmintic effect of CLP on H. contortus. The cranberry leaves were obtained from local cranberry producers, A.D. Makepeace Company, based in Wareham, Massachusetts. They are the world’s largest cranberry grower as well as the largest private property owner in eastern Massachusetts. The cranberry leaves and vines were collected in the spring, during the pruning process, when they are cut from the bogs and kept fresh and watered. We obtained 1000 pounds of the leaves and vines and dried them in burlap bags. The leaves were ground and fed as a supplement mixed with chopped hay and molasses. This was fed at 0, 100 and 200 grams of dried cranberry leaf powder. The control and cranberry leaf supplement were fed to lambs (n=7 lambs per group) for five weeks. After the five week feeding trial, lambs were sent to the abattoir and their abomasums were collected for quantification and fecundity of individual lambs’ worm burden. Analysis of data from the lamb trial and data collected from the individual worm burdens are still in progress. No final results have been determined yet.

Objectives/Performance Targets

The specific objectives of this study are:

• • To develop a grain supplement containing varying concentrations of cranberry leaf powder that lambs will readily consume.

• • To determine the anti-parasitic potential of varying concentrations of cranberry leaf powder provided daily, through a grain supplement, to lambs experimentally infected with Haemonchus contortus.

Objective 1:  This objective was accomplished with one modification; lambs were fed the CLP directly, instead of incorporating the CLP into a grain pellet. Difficulty obtaining access to a grinder that would process the CLP fine enough for pelleting in the quantities needed, coupled with the discovery that lambs readily ate the CLP when mixed with a chopped alfalfa hay and molasses, the decision was made to feed the CLP directly. We resolved to feed the CLP as an additive to a diet instead of incorporating it into a grain pellet.  

Objective 2:  Lambs, experimentally infected with Haemonchus contortus, were fed 0, 100, or 200 grams of CLP daily for five weeks and fecal egg count and packed cell volume were monitored weekly. At the conclusion of the trial, the abomasum of each lamb was collected and individual worm burden was determined. Effects on the egg laying ability of female worms (fecundity) and determination of the sex ratio of the worms recovered, followed by statistical analysis of the results are in progress. We also had the opportunity to collect worms from each lamb for Electron Microscopic analysis of the effects of the varying concentration of CLP on the outer cuticle of the adult worms collected from the abomasum. These worms will be evaluated in the coming months.

Accomplishments/Milestones

The overall project did not progress as planned and did require us to make course corrections along the way, but the end goal of the project was still achieved and the lamb trial was completed. The project can be viewed in two parts, based on objectives:

Objective 1 is the development of a grain supplement incorporating cranberry leaf powder. We were unable to develop a grain supplement because of a lack of equipment that could grind the cranberry vines into small enough particles to be pelletized in the quantities needed. With some small palatability tests, we were able to create a mixture of chopped alfalfa hay, molasses and CLP that was enticing to the lambs. For this objective, we were able to develop a supplement containing varying concentrations of CLP that lambs would readily consume.

Objective 2 is the determination of the anti-parasitic potential of CLP. Using the CLP diet, we were able to provide CLP daily to lambs experimentally infected with H. contortus, for five weeks. Data on the fecundity of female worms, sex ratio, electron microscopic evaluation and statistical analysis of the data is underway and expected to be completed by May 2016.

Impacts and Contributions/Outcomes

The project is still in the analysis stages; therefore no final results have been determined. In the overall vision of this project, we can estimate significant potential impacts which could contribute to agricultural sustainability. This project has the potential for major contributions to whole-farm sustainability and productivity. If the CLP supplement has an anthelmintic effect against H. contortus infections in lambs, this could have the potential to provide an organic, natural alternative to synthetic dewormers. This could potentially decrease producer reliance on synthetic dewormers. A reduced amount of chemical residue on pastures would be environmentally beneficial for the soil microorganisms that aid in pasture productivity and nitrogen fixation. As a result, the use of CLP may lead to an overall improvement in the whole-farm system, reducing environmental and health risks in agriculture. The GIN health concerns that are associated with putting lambs on pasture would also be addressed with the potential of this natural anthelmintic. Having lambs on pasture is a major health risk faced by small ruminant producers worldwide, establishing a crucial need for this project. Through reducing health risks like GIN infections, this would ultimately improve productivity due to lower worm burden, as well as reduce costs and increase the net farm income in conjunction with a decreased use of chemical dewormers.

We will provide updates on the project results through extension factsheets, scientific meetings and our small ruminant website. The project progress was shared with producers in the July 2015 workshop focused on integrated gastrointestinal parasite control. At this workshop producers were updated on the results of ongoing parasite control research from our laboratory. The beneficiaries of this project include small ruminant producers, extension agents, researchers as well as undergraduate and graduate students. Providing this alternative method of GIN control will also assist farmers to realize increased earnings through reduced use of synthetic dewormers and increased animal productivity attributed to lower worm burden.

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