Schoenian, S. , Sheep & Goat Specialist, University of Maryland
O'Brien, D. , Small Ruminant Specialist, Virginia State University
Semler, J., Extension Educator, University of Maryland
Gordon, D., Extension Educator, University of Maryland
Bennett, M., Extension Educator, West Virginia University

ABSTRACT

The barber pole worm (Haemonchus contortus) is the most common and pathogenic worm species affecting small ruminants. In 2014, meat goat bucks (n=74) participating in the Western Maryland Pasture-Based Meat Goat Performance Test were used to determine the effect of copper oxide wire particles (COWP) on barber pole worm infections. Midway through the 84-d test, bucks (n=9) showing clinical signs of Haemonchus were orally dosed with a commercial dewormer (TX). All other bucks (n=65) were dosed with 0.5 g of COWP (COWP). Copasure® boluses for cattle were repackaged into smaller doses for goats. Fifteen bucks (n=15) that were part of another study, but grazed alongside bucks in the test, were not treated, and served as controls (CON). Fecal samples were collected pre-treatment and at 14 and 28 days post-treatment. Individual fecal egg counts (FEC) were calculated and treatment efficacy was determined according to the guidelines established by the W.A.A.V.P. Pre-treatment FEC averaged 4251 ± 1263, 2515 ± 280, and 2164 ± 323 eggs per gram (epg), respectively, for the TX, COWP, and CON groups. After treatment, FEC averaged 164 ± 48, 588 ± 96, and 2317 + 574 epg, respectively, for the TX, COWP, and CON groups. Treatment with COWP reduced FEC by 74.6 ± 0.09% (53-86 % CI), compared to 92.9 ± 0.09% (84-96% CI) for the commercial dewormer(s). There was no reduction in FEC in the CON group. COWP were determined to be moderately effective at reducing FEC, but the effect was less than for the commercial dewormer and by d-28, FEC had increased to pre-treatment levels, indicating treatment with COWP was short-lived.

Introduction

The US meat goat industry has grown significantly in recent decades, but continues to face production challenges. One of those challenges is gastrointestinal parasites (worms), the primary health problem affecting small ruminants in warm, moist climates like Maryland. The barber pole worm (Haemonchus contortus) is the most common and pathogenic worm species. It has developed resistance to all available dewormers and dewormer classes (Crook et al., 2016; Howell et al., 2008). Therefore, alternatives to commercial dewormers are needed, if small ruminant production is to remain viable and expand to meet the growing demand for its products.

Copper oxide wire particles (COWP) are tiny rods of copper oxide (CuO₂). Compared to copper sulfate (CuSO₄), they are a slow release form of copper, with much less potential to cause copper toxicity. Copper sulfate is a historic dewormer that was known to sometimes cause copper toxicity (in sheep). COWP are marketed in bolus form to treat copper deficiency in cattle and goats. They have been shown to reduce barber pole worm infections in goats and sheep (Hale et al., 2007); however, results of studies have been variable.

 

Materials and Methods

The Western Maryland Pasture-Based Meat Goat Test was initiated in 2006 at the University of Maryland’s Western Maryland Research & Education Center in Keedysville. The purpose of the test was to evaluate the post-weaning performance of meat goat bucklings consuming a pasture-based diet, with natural exposure to internal parasites, primarily the barber pole worm. The primary goal of the test was to identify bucks that demonstrated resistance and resilience to internal parasites. Resistance was quantified by fecal egg counts. Resilience was quantified by FAMACHA© scores and number of anthelmintic treatments.

From 2011-2014, studies were conducted to compare the health, performance, and carcass characteristics of pen-fed vs. pasture-raised meat goats. In 2014, thirty Kiko bucklings were randomly assigned to two treatment groups: PEN vs. PASTURE. The goats in the PASTURE group grazed alongside the bucks in the pasture test. The same data was collected on the bucks in the study as in the test.

In 2014, bucks (mostly Kiko) from the test (n=74) and study (PASTURE, n=15) were used to determine the effect of COWP on barber pole worm infections. Mid-way through the 84-d test, test bucks (n=9) showing signs of clinical parasitism, as determined by FAMACHA© scores and the Five Point Check®, were orally dosed with a commercial dewormer, either levamisole (Prohibit® @ 3 ml of concentrated drench per 50 lbs.) or moxidectin (Cydectin® sheep drench @ 2 ml/11 lbs.) [TX]. Data from a DrenchRite® test and fecal egg count reduction tests had demonstrated both of these dewormers still had efficacy >95% in this population of goats.

All other bucks were given 0.5 g of COWP [COWP]. Copasure® boluses (Animax, 12.5 g) for cattle were repackaged into smaller doses (gel caps) for goats. The gel caps were administered using a plastic balling gun. The bucks (n=15) from the PASTURE group of the pen vs. pasture study were not treated and served as controls (CON) for the experiment.

A pooled fecal sample was collected from random goats. The sample was submitted to Dr. Ray Kaplan’s lab at the University of Georgia for fecal coproculture. Individual fecal samples were collected from the rectum of each buck before treatment (d-0) and 14 and 28 days after treatment. Fecal egg count (FEC) was determined by Dr. Dahlia O’Brien’s laboratory at Virginia State University. A modified McMaster protocol was used to determine egg counts (Coles et al., 1992). Treatment efficacy was determined according to the guidelines established by the World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) (Coles et al., 1992). Percent fecal egg count reduction = 100 (1- X̄t/ X̄c) where t is the treated group egg count average and c is the control group average.

 

Results

Eighty-seven percent of the worm load was determined to be the barber pole worm. Treatment with COWP reduced FEC by 74.6 ± .09% (53-86% CI), compared to 92.9 ± .09% (84-96% CI) for the commercial dewormers. There was no fecal egg count reduction in the CON group. By day 28, FEC increased in all three groups (Table 1 and Figure 1).

 

Table 1. Fecal egg counts (eggs per gram; epg) by day (d) and treatment group.

Group	d 0	d 14	d 28
Tx	4251 +/- 1263	164 +/- 48	1782 +/- 547
COWP	2515 +/- 280	588 +/- 96	2514 +/- 337
CON	2164 +/- 323	2317 +/- 574	4493 +/- 1173

 

Figure 1. Average fecal egg counts (FEC) over duration of buck test, eggs per gram (epg).

 

Conclusions

COWP were determined to be moderately effective at reducing FECs, but their effect was less than for the commercial dewormers (levamisole and moxidectin) and by day 28, FEC had returned to pre-treatment levels, indicating treatment with COWP was short-lived.

COWP may offer an alternative to goat farms with high levels of resistance to the commercial dewormers. Based on their demonstrated FEC reduction, they should provide a clinical response. COWP may also be used in combination with commercial dewormers, as this has been shown to increase dewormer efficacy (Burke, et al., 2016).

To prevent possible copper toxicity, especially in sheep, the lowest possible dose of COWP should be used. Doses that have proven effective are 0.5 to 1.0 g per kid (or lamb) and 1 to 2 g for doe (or ewe) (Coffey, 2018).

 

References

Burke, J. Miller, T. Terrill, E. Smyth, and M. Acharya. (2016). Using copper oxide wire particles to increase dewormer efficacy. Veterinary Parasitology 215:1-4.

Coffey, L. Copper oxide wire particles. (2018). Best management practices for internal parasite control in small ruminants. American Consortium for Small Ruminant Parasite Control.  www.wormx.info.

Coles, G.C., C. Bauer, F.H.M. Borgsteede, S. Geerts, T.R. Klei, M.A. Taylor, and P.J. Waller. (1992). World Association for Advancement of Veterinary Parasitology (W.A.A.V.P.). Methods for detection of anthelmintic resistance in nematodes of veterinary importance. Veterinary Parasitology, 44:35-44.

Crook, E. J., D.J. O’Brien, S.B. Howell, B.E. Storey, N.C. Whitley, J.M. Burke, and R.M. Kaplan. (2016). Prevalence of anthelmintic resistance on sheep and goat farms in the mid-Atlantic region and comparison of in vivo and in vitro detection methods. Small Rum. Res. 143:89–96.

Hale, M, J. Burke, J. Miller, and T. Terrill. (2007). Tools for managing internal parasites; copper oxide wire particles. NCAT-ATTRA.

Howell, S.B., Burke, J.M., Miller, J.E., Terrill, T.H., Valencia, E., Williams, M.J., Williamson, L.H., Zajac, A.M., Kaplan, R.M. (2008). Prevalence of anthelmintic resistance on sheep and goat farms in the southeastern United States. Journal of the American Veterinary Medical Association. 233: 1913-1919.

 

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