Grazing Forages High in Condensed Tannins and its Effect on Fecal Egg Counts in Meat Goats

Final Report for FNC05-564

Project Type: Farmer/Rancher
Funds awarded in 2005: $6,000.00
Projected End Date: 12/31/2007
Region: North Central
State: Ohio
Project Coordinator:
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Project Information


This project was conducted on a 30-acre meat goat operation nestled in the rolling hills of southeastern Ohio. The 25 acres of pastureland is divided up into 18 paddocks with fresh water accessible in each paddock. The paddocks are planted to a variety of different warm season grasses / legumes and cool season grasses / legumes. We are currently running a herd of approximately 60 does of various ages and evaluating the productivity and effectiveness of the different forages

This project studied the use of forages containing moderately high levels of condensed tannins (CT) in a browsing system with meat goats and the resulting effect on fecal egg counts of internal parasites. The goal of this project is to reduce or eliminate the use of anthelmintics in meat goats through holistic and sustainable management of forages.

In 2005-2006, I established the forages that were used in the study. AU Grazer Lespedeza, developed at Auburn University was planted in several paddocks mixed with a variety of warm season grasses. AU Grazer was selected for its ability to withstand haying and grazing and contains moderately high levels of CT. Two paddocks of previously established warm season grasses and three paddocks of a tall fescue / clover mix were also used in the study.

I purchased portable shelters needed to keep the goats in the paddocks in which the study was being conducted so there would be no possibility of them foraging outside their paddock or no need for them to intermingle with one another.

Weather Conditions Affecting the Study: Abnormal weather conditions had a significant impact on this study. In April of 2007, Ohio experienced a hard freeze. Most of the forages, including the warm season grasses and legumes had already broken dormancy and were actively growing. The birdsfoot trefoil and the lespedeza were frozen to the ground. The birdfoot trefoil did not fully recover. I had to re-seed it this spring, which meant I couldn’t graze it this year.

At first it appeared that the lespedeza was also lost. But after a couple of weeks, it began to re-sprout from the roots. This delayed the start of the study until mid June in an effort to allow the forages to recover. As a result of this freeze, I had to modify the study to look at cool season grasses as the control group, warm season grasses (rather than the birdsfoot trefoil) and lespedeza.

In addition, most of the Midwest experienced a moderate to severe drought during the summer months. This, combined with the spring freeze significantly reduced production and the study was cut short due to a shortage of forages. Good data was collected however over a period of three and a half months. The data showed significant differences in the forages and established a clear trend.

How the Study Was Conducted: Thirty does were treated with an effective anthelmintic. They were randomly divided into three groups of ten and turned out into the demonstration paddocks beginning June 20th 2007. Each group had access to fresh water, mineral and portable housing. None of the goats in the study were provided supplemental feed.

The control group was turned out into paddocks of a cool season mix of tall fescue and clover typically found in Ohio. Another group was turned out into warm season easterngama grass and switchgrass paddocks. The third group was turned out into paddocks established in lespedeza.

FAMACHA tests were conducted weekly. Fecal samples were taken and evaluated monthly for egg counts of internal parasites.

David Mangione, Ross County Ohio Ag Agent for The Ohio State University Extension assisted with the FAMACHA evaluations so that the same person conducted the evaluation each week to help ensure consistency. He also assisted with the collection of fecal samples.

A licensed veterinarian who did not know which samples came from which group of goats processed the fecal samples blindly.

Discussions and Results of the Study:

1) The results of the study clearly showed an advantage of grazing lespedeza. By the end of August, six of the ten goats browsing lespedeza showed 0 (zero) egg counts. By the end of the next month, at a time when parasites are at their worst, the egg counts of every goat browsing lespedeza indicated 0 (zero) eggs. These goats maintained excellent body condition throughout the summer with no supplemental feeding. Not only were they free of parasites and in excellent condition but they were not shedding eggs and contaminating the pasture.

2) The group browsing warm season grasses also resulted in fecal egg counts considerably lower than the control group. There were no forages containing condensed tannins in these paddocks. It is my contention that they had a lower worm load simply because they were browsing six feet high forages down to about 18 inches. For the most part they were not grazing low to the ground where they would have a higher tendency to pick up parasite larvae.

3) Another finding that came from the study is that the FAMACHA evaluation is a useful tool for a general evaluation but should not be the sole means of tracking parasite load. Some animals evaluated equally using the FAMACHA system yet showed significant differences when fecal samples were collected and evaluated. To get an accurate measure of worm load, a fecal egg count should be conducted.

4) Some individual goats seem to be much more susceptible to parasites than others. Fecal egg counts verified that individual goats within each group were “carriers” and had consistently higher egg counts than others in the group. Through the summer there was only one doe in the control group that needed to be dewormed. She was showing signs of bottle jaw. Interestingly after a couple of months time, her egg counts were higher than where they were prior to deworming… higher than any other doe in her group even though she was the only one who had been dewormed.

Conversely some individuals seemed to consistently have a lower fecal egg count than most of the others in their group grazing in the same paddock. This natural resistance should be capitalized upon when selecting individuals for breeding stock. This should help incorporate this natural resistance over time into the herd.

It appears that goats browsing forages containing condensed tannins do in fact benefit from a reduction in parasites. This has been shown through FAMACHA evaluations, by general body condition and by fecal egg counts.

Browsing tall forages such as warm season grasses seem to also reduce parasite load. This is most likely due to reduced ingestion of parasite larvae thereby interrupting the life cycle of the parasite.

This project demonstrates the possibility of reducing or eliminating the use of anthelmintics through the use of forages and browsing management. This will save the producer time and money that is normally needed for deworming. From all indications, it will also reduce mortality due to high parasite load and could save money in feed costs due to the fact that the goats browsing lespedeza maintained much better body condition than the other two groups. A side economic benefit is the reduced use of nitrogen fertilizer by establishing legume based browsing systems.

Future Subjects for Study:
* I am interested in knowing if parasites will gain resistance to the condensed tannins as they have been known to do with chemical anthelmintics. I would like to continue this study to see if the egg counts begin to rise over time.

* It is commonly believed that condensed tannins can adversely affect conception rates in animals consuming forages containing condensed tannins. It would be interesting to develop a study to see if this is in fact the case.

In the fall of 2006, I gave a farm tour to approximately 10 USDA NRCS state office personnel.

In June of 2007, I gave a presentation to about 120 professional goat producers at a meat goat symposium held in Wilmington, Ohio on the subject of developing a browsing management system for meat goats.

I have met with several producers individually who wanted a tour of the farm.

In September 2007, I met with SARE Farmer Rancher Grant Program Coordinator, Joan Benjamin at the farm. There were several Ohio State University Extension Ag agents from surrounding counties that also attended and toured the farm. After the tour they expressed interest in having a multi-county field day in 2008 at the farm to review the project with producers.


Participation Summary
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.