Copper oxide wire particles to control H. contortus on sheep and goat farms with a range of grazing practices

Final report for LNE13-327

Project Type: Research and Education
Funds awarded in 2013: $46,552.00
Projected End Date: 10/31/2017
Grant Recipient: Cornell University
Region: Northeast
State: New York
Project Leader:
Dr. Michael Thonney
Cornell University
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Project Information

Summary:

Copper oxide wire particles (COWP), an alternative to chemical anthelmintics, have been shown to effectively reduce infection of barber pole worm (H. contortus) in the southeastern US. The objectives of this project were twofold.  One objective was to encourage goat and sheep farmers to limit anthelmintic use through education on innovative strategies for controlling internal parasites including evasive grazing and targeted selective deworming. Dosing with COWP or grazing high tannin forages such as Birdsfoot trefoil to reduce H. contortus infection is as yet unproven in the northeastern US.  Therefore a second objective was to determine the effectiveness and risks of incorporating COWP  into northeastern parasite management systems and report results from COWP and BFT studies to farmers.

Thirteen on-farm trials studying the effect of COWP dosing on goats and sheep were conducted from 2013 through 2017. Fecal samples and FAMACHA scores were taken on DAY 0 (immediately before oral dosing with COWP) and fortnightly for 4 to 8 weeks after COWP dosing and animals were weighed at the beginning and end of each trial. Total strongyle eggs per gram (SFEC) were determined for each individual fecal sample.  A lectin binding stain using a peanut agglutinin (PNA) was then used to calculate what percentage of the SFEC were H. contortus eggs to determine H. contortus eggs per gram (HFEC).

Variance components for FAMACHA scores, SFEC and HFEC and weight change were analyzed in Minitab with mixed model equations using restricted maximum likelihood methods with random effect of animal nested in Treatment and fixed effects of Treatment (COWP or no COWP) and Day and their interaction.  Fixed effects of sex, breed or forage type (BFT versus no BFT) and respective interactions were also included where applicable. Both SFEC and HFEC were log-transformed prior to statistical analysis to normalize the data. If no significant Treatment by Day effect (indicating a long term impact of COWP throughout the trial) was found, we then tested whether there was a short term effect by analyzing variance components for CHG_SFEC and CHG_HFEC expressed as the change in the untransformed FECs from Day 0 to Day 14  using a general linear model with fixed effects of Treatment. Results were quirt variable among farms, ranging from one farm showing significant long term effects of COWP dosing during each of 3 annual studies to some farms showing no significant long or short term effects. We suspect that specific flock factors influence the amount of copper exposure actually experienced by susceptible worm populations in host animals. Animal species (goat versus sheep), diet, weaning status, extent of barber pole worm infection at the time of oral dosing, and/or past exposure of the barber pole worm gene pool  to copper on individual farms could possibly influence effectiveness. Further controlled studies are needed to determine which of these factors help explain the variation in COWP effectiveness for barber pole worm control observed across different farms. Until factors contributing to effectiveness are better understood, a prudent method of incorporating COWP dosing into a parasite management program would be to conduct 5 point checks, including FAMACHA scoring, on flocks or herds at least fortnightly during the grazing season and to use COWP dosing on vulnerable animals with FAMACHA scores of 3 while reserving effective dewormer(s) for animals with FAMACHA scores of 4 or 5. Study results indicate that when COWP is effective in Northeast flocks, a dosage of 0.5 g is as effective as larger dosages in lambs. In lactating dairy goats, dosages of 2 g of COWP per head were significantly more effective than 1 g per head dosages and as effective as dosages of 1/g per 22 lbs live weight and resulted in lower levels of copper in the milk 2 weeks after dosing. Our studies were less clear on dosages for mature ewes or goat kids.       

More than 1200 farmers. interns, service providers and educators attended small ruminant parasite management workshops, field days and presentations associated with the project. Approximately 460 attendees participated in our IPM/FAMACHA trainings and became FAMACHA certified. In March 2016, 553 past program participants were invited to participate in a follow up survey. Usable surveys were returned by 170 participants with 138 of these being fully completed. Fifty-two respondents indicated that they reduced their use of synthetic dewormers as a result of practices they adopted or improved upon because of our programs. Reported annual savings in dewormer costs ranged from $30 to $500, averaging $143. Few farmers provided monetary values from improved animal performance.  When reported, earnings from improved animal productivity ranged from $100 to $1400 (average $557), savings in health costs (vet bills, labor to treat parasitized animals) ranged from $100 to $1000 (average $300), and savings from reduced animal mortality ranged from $400 to $2000 (average $1180).   

Introduction:

Haemonchus contortus (barber pole worm) is ubiquitous in sheep flocks and goat herds. An online December 2011 survey sent to list-servers and our data base of 3,825 people interested in sheep and goat farming reported recent H. contortus (73%) problems with more than 2/3 finding labor and treatment costly. Overuse of chemical dewormers has allowed the worm population to develop resistance. Copper oxide wire particles (COWP) are an alternative to chemical anthelmintics. COWP have effectively reduced infection of H. contortus in the Southeast US, but it is not clear how safe and effective COWP are in the Northeast.

This project proposed to 1) educate farmers about how to integrate limited anthelmintic use with other innovative strategies for controlling internal parasites and 2) determine effectiveness and risks of incorporating different dosages of COWP into parasite management systems for Northeast farms. Through web pages, FAMACHA certification workshops, symposia, field days, presentation s and regional meetings, the project encouraged farmers to reduce use of chemical anthelmintics by adopting effective minimum use strategies that maintain susceptibility of internal parasites to available dewormers. Trials of COWP dosing were replicated on 9 NY farms using lambs and kids randomly assigned within farm to Control or one to two levels of COWP. Initially, the project proposed to use only weaned lambs and kids, and two levels of COWP (0.5 g and 2.0 g). However, advice from Southeast researchers and experiences during the first year of experiment, resulted in testing out different levels of COWP on some farms and comparisons of COWP dosing 2 weeks pre and post weaning. In addition, one farm studied the effect of COWP on lactating ewes as well as on self-weaning lambs and a trial on a 10th farm studied COWP dosing in lactating dairy goats. Three studies also compared the effects of birdsfoot trefoil (BFT) grazing as well as COWP dosing on H. contortus infections in goats or sheep.

Performance Target:

Of 100 participating farmers surveyed, 75% will report deworming less and reducing their chemical dewormer costs by as much as $215 in a 100-doe or ewe flock, citing adoption of FAMACHA and other non-chemical internal parasite control methods. The low dose of COWP will reduce deworming cost by $142 compared with chemical dewormers with the added potential benefits of some farmers being able to meet organic farming standards and other farmers maintaining the effectiveness of selective use of chemical anthelmintics. Most importantly, these strategies both reduce deaths from internal parasites from as many as 18 animals per year to 5 animals per year, increasing income by $2,205 in a herd or flock of 100 mature females.

Cooperators

Click linked name(s) to expand
  • Betsy Hodge (Educator)
  • Dr. Mary Smith (Researcher)
  • Dr. Tatiana Stanton (Educator and Researcher)
  • Dr. Dwight Bowman (Researcher)
  • Janice Liotta (Researcher)

Research

Hypothesis:

The research hypotheses are that COWP use is as effective as chemical anthelmintics to control H. contortus and that a low dose is as effective as a medium dose. 

Materials and methods:

Thirteen on-farm trials studying the effect of COWP dosing on goats and sheep were conducted from 2013 through 2017. Initially, the project proposed to use only weaned lambs and kids, and two levels of COWP (0.5 g and 2.0 g) and to treat the trials as replicates. However, advice from Southeast researchers and experiences during the first year of project resulted in testing different levels of COWP on some farms and comparisons of COWP dosing 2 weeks pre- and post-weaning. Opportunities also arose to study the effects of COWP on mature ewes with lambs at their side at one farm and on milking dairy does at another. In addition, three of the farms involved in our separate study evaluating the effects of grazing birdsfoot trefoil pasture on strongyle worm infection also opted to study the effects of COWP. Therefore, the studies were more complex than originally planned (Table 1).

Table 1. Treatment summaries for 13 trials studying the effects of COWP on small ruminant parasite infection.

Trial Farm/ year

Type of animals

Treatments

Sampling Time

Weaning status at trial start

Dairy Goat#1 2013

46 lactating dairy does

15 does, 1 g COWP; 15 does, 2 g COWP;
16 does, 1 g COWP/10 kg live wt.

Day 0, 14, 28, 42

NA

Sheep#1
2013

45 ewe and ram Dorset X lambs (only 24 were fecal sampled)  

15 lambs, no COWP; 15 lambs, 0.5 g COWP; 15 lambs, 1 g COWP;

Day 0, 14,
28, 42

2 wk pre-
weaning

Sheep#2
2013

45 ewe and ram Katahdin lambs (only 24 were fecal sampled)  

15 lambs, no COWP; 15 lambs, 0.5 g COWP; 15 lambs, 1 g COWP;

Day 0, 14,
28

5 wk post
weaning

Sheep#3
2013

45 ewe and wether Dorset X lambs (only 24 were fecal sampled)  

15 lambs, no COWP; 15 lambs, 0.5 g COWP; 15 lambs, 1 g COWP;

Day 0, 14,
28

2 wk post
weaning

Sheep#1
2014

40 ewe and ram Dorset X lambs

8 lambs; no COWP; 8 lambs, 0.5 g 2 wk pre-wean; 8 lambs 1 g 2 wk pre-wean; 8 lambs, 0.5 g 2 wk post wean; 8 lambs 1 g 2 wk post wean

Day 0, 15, 36, 48, 64

2 wk pre – weaning

Sheep #4
2014

40 ewe and ram Dorset X lambs

8 lambs; no COWP; 8 lambs, 0.5 g 2 wk pre-wean; 8 lambs 1 g 2 wk pre-wean; 8 lambs, 0.5 g 2 wk post wean; 8 lambs 1 g 2 wk post wean

Day 0, 14,28, 42

2 wk pre – weaning

Sheep#5
2014

12 Clun Forest ewe and ram lambs; 12 Romney X ewe and ram lambs

8 lambs, no COWP;
8 lambs, 0.5 g COWP; 
8 lambs 1 g COWP

Day 0, 14, 28

Self weaning 60 to 90 days old at start of trial

Sheep#5
2014

12 Clun Forest ewes; 11 Romney X ewes; 1 Rambouillet ewe;
all w/lambs at side.

8 ewes, no COWP;
8 ewes, 1 g COWP;
8 ewes, 2 g COWP

Day 0, 14, 28

lambs 60 to 90 days old at trial start

Meat goat#1
2014

24 Boer doe and wether kids

8 kids, no COWP;
8 kids, 0.5 g COWP;
8 kids 1 g COWP

Day 0, 14, 28

Self weaning
averaged 118 days old at start of trial

Meat goat#2
2015

32 Boer doe and wether kids

8 kids, no COWP; 8 kids, 0.5 g; 8 kids 1 g; 8 kids, 1.5 g

Day 0, 14, 28, 41

2 wk pre-
weaning

Sheep#1
2015

40 ewe and ram Dorset X lambs

8 lambs, no COWP/Non BFT pasture; 8 lambs, 1 g 2 wk pre-wean/Non BFT pasture; 8 lambs, no COWP/BFT pasture; 8 lambs, 1 g 2 wk pre-wean/BFT pasture; 8 lambs, 1 g 2 wk pre-wean/ hay and grain

Day 0, 14, 28,

2 wk pre- weaning

Meat goat#3
2016

18 Kiko X buck and wether kids

9 kids, No COWP/BFT pasture; 5 kids, No COWP/ Non BFT pasture; 4 kids, 2 g COWP on Day 29/ Non BFT pasture

Day 0, 15, 29, 41, 57

3 days post weaning

Fiber goat#1
2017

6 Cashmere buck kids, 10 Angora buck kids

4 kids, No COWP/BFT pasture;
4 kids, 1 g COWP on day 42/ BFT pasture; 4 kids, No COWP/ non-BFT; 4 kids, 1 g COWP day 42/ non BFT pasture

Day 0, 14, 28, 42, 56

6 days post weaning

Fecal samples and FAMACHA scores were taken on day 0 of each trial and approximately fortnightly for 4 to 9 weeks. Kids and lambs were weighed at the beginning and end of each trial, and at weaning if weaned during the trial. Total strongyle eggs per gram (SFEC) were determined by McMaster procedures for each individual fecal sample.  A lectin binding stain using a peanut agglutinin (PNA) was then used to calculate the percentage of the SFEC that were H. contortus eggs to obtain H. contortus eggs per gram (HFEC).

Variance components for FAMACHA scores, SFEC and HFEC and weight change were analyzed in Minitab with mixed model equations using restricted maximum likelihood methods with random effect of animal nested in COWP and fixed effects of COWP and Day and their interaction.  Fixed effects of sex, breed or forage type (BFT versus no BFT) and respective interactions were also included where applicable. Both SFEC and HFEC were log-transformed prior to statistical analysis to normalize the data. If no significant COWP by Day effect was found (indicating no long term impact of COWP throughout the trial), variance components for CHG_SFEC and CHG_HFEC expressed as the change in the untransformed FECs from Day 0 to Day 14 were analyzed using one-way analysis of variance with the effect of level of COWP treatment.

We did not follow through on analyzing liver samples for copper levels because 1) preparatory liver sampling showed more variation between liver samples taken from the same livers than previously anticipated and 2) the logistics to retrieve liver samples from specific lambs and treatments at the commercial slaughter houses proved difficult.  Instead, blood samples were collected from all animals in the 2013 studies and in the “Sheep#1 2014” and “Sheep#4 2014” studies to analyze plasma for aspartate aminotransferase (AST) enzyme concentration, an indicator of copper toxicity. Milk samples were taken on days 0, 14 and 42 from the milking dairy does in trial “Dairy goat#1 2013” to analyze for copper content using inductively coupled plasma-atomic emission spectroscopy.

Research results and discussion:

Results for Dairy goat#1 2013

In this study, there was no long term effect of COWP level (i.e. COWP * Day) on either FAMACHA score (P = 0.68), overall strongyle fecal egg counts (SFEC, P=0.70) or H. contortus fecal egg counts (HFEC, P = 0.54 ) observed in the REML analysis. However, H. contortus decreased  similarly from 0 to 14 days (CHG_HFEC) for does receiving 1 g COWP/10 kg live wt. (HCOWP) and 2 g COWP/head (MCOWP); changes were -1153 ± 469.4 and -1226 ± 484.8 epg, respectively, while CHG_HFEC increased by 107 ± 484.8 epg for does getting 1 g/head (LCOWP; P = 0.036). Curd formation for 4 cheese types remained consistent the week following COWP treatment. Milk copper increased slightly between Day 0 (0.131 ppm) and Day 14 (0.174 ppm) but individual values were all within the pre-treatment range and COWP level had no effect. Changes in copper concentration from 0 to 42 days were not significant. However, in separate paired t tests, copper concentrations increased significantly (P = 0.003) from 0.105 ± 0.019 to 0.171 ± 0.019 ppm from 0 to 14 days for HCOWP but not for MCOWP (P = 0.12) or LCOWP (P = 0.14). Copper toxicity elicits AST activity of >300 ppm. Plasma AST concentrations on day 42 were 118 ± 6.9, 121 ± 7.2, and 113 ± 7.2 ppm for HCOWP, MCOWP and LCOWP, respectively, and did not differ significantly. In this study, dosing dairy does with 2 g COWP/head as compared to 1 g/10 kg live weight caused similar reductions in H. contortus epg and significantly lower increases in milk copper concentrations from Day 0 to Day 14.

Results for  Sheep#1, Sheep#2 and Sheep#3 2013 and Sheep#5 2014

These studies were done on weaning age lambs on four NY farms across New York State. There were 3 COWP treatments: CONTROL (no COWP), LCOWP (.5 g COWP/head) and HCOWP (1 gram COWP/head).  The initial analysis only included the 3 trials conducted in 2013.  Previous U.S. studies had yielded disappointing results when COWP was administered at weaning possibly due to stress or pH changes in the abomasum accompanying the sudden changes in diet experienced then. Therefore, lambs were not dosed with COWP at weaning but were instead dosed at 2 wks. pre-weaning, 5 wks. post weaning and 2 wks. post weaning for Sheep#1, Sheep#2 and Sheep#3 respectively. The ANOVA procedure used to in 2014 to analyze the log transformed H. contortus epg (HFEC ) for each farm over the course of 28 to 42 days was a mixed model including effects of COWP, lamb within COWP, Day and COWP x Day. In Sheep#1 the effect of COWP (P = 0.033), and COWP x Day (P = 0.026) were significant. Neither the effect of COWP (P < 0.881) or COWP x Day (P < 0.685) was significant for Sheep#2, and effect of COWP was almost significant (P < 0.085) whereas COWP*Day was not for Sheep#3.  

However, if we looked only at the change in H. contortus epg (CHG_HFEC) from Day 0 to Day 14 using  a general linear model  run on all three farms including the effects of farm, COWP, sex and their interactions, the effects of farm (P < 0.005), COWP (P < 0.003) and Farm*COWP (P < 0.056) were all significant.  

Thus, COWP appeared highly effective at both the 0.5 and 1 g/head dosage on Sheep#1 where it was administered 2 weeks prior to weaning. The effect on this farm carried over for the full 42 days (28 days post weaning) of the study. However, COWP effects on Sheep#2 and Sheep#3 where it was given several weeks post weaning were more variable. The changes in diet at weaning may be one explanation for the differences observed between farms. Prior to weaning, much of the diet is liquid.  The lack of substantial forage in the digestive tract may make it easier for COWP to become embedded in the abomasum.  In addition, it may be that more of the COWP bypasses the rumen and is shunted directly through the esophageal groove to the abomasum in suckling versus weaned lambs. Thirdly, the pH of the abomasum is probably different in milk-fed versus weaned lambs resulting in different rates of copper solubility. However, other factors were different between the farms including rate and timing of H. contortus infection, pasture management and level of nutritional supplementation. Thus, we cannot determine what factors explain the observed differences in COWP effectiveness.  

Average daily weight gains over the course of the study were analyzed across the 3 sheep farms using a general linear model including farm, sex, COWP treatment (Control versus LCOWP and HCOWP, and LCOWP versus HCOWP) and interactions between the effects. Average daily gains for Sheep#1, Sheep#2 and Sheep#3 were 67 ± 8.7, 269 ± 8.7 g/day and 217 ± 8.7, respectively (P < 0.001). Average daily gains for male and female lambs were 203 ± 7.1 and 166 ± 7.1 g/day (P < 0.001). Average daily gains were 173 ± 8.6, 186 ± 8.6 and 194 ± 8.6 g/day for Control, LCOWP and HCOWP respectively. The effect of giving COWP (LCOWP and HCOWP) versus the effect of not giving COWP (Control) was almost significant (P < 0.097) whereas there was not a significant difference (P < 0.471) between the effect of LCOWP (0.5 g of COWP) versus HCOWP (1 g COWP).

In 2017, the data from these 3 studies and Sheep#5 2014 were analyzed again with a mixed model using restricted maximum likelihood methods with random effect of animal nested in COWP and fixed effects of COWP and Day and their interaction.  Sheep#1 where lambs received COWP two weeks pre- weaning was analyzed separately from the other 3 farms.  The effect of Day (P < 0.001) but not COWP (P = 0.352) or COWP x Day (P = 0.079) was significant for FAMACHA score. The effect of both COWP (P = 0.012) and Day (P = 0.001) but not COWP x Day (P = 0.114) was significant for SFEC while COWP(P = 0.011), Day (P = 0.001) and COWP x Day (P = 0.051) were all significant for HFEC. Three lambs were killed by coyotes the last week of the trial.  Two of these 3 lambs were CONTROL lambs that had been tagged as “keep an eye” on at the last sampling period because of FAMACHA scores verging on 4 and general appearance. Another CONTROL lamb was the only lamb immediately dewormed at the end of the study because of a FAMACHA score of 4 and general appearance.

Table 2. Sheep#1 2013 means and P values for effects of COWP, Day and COWP*Day

       

Strongyles

Haemonchus

Effect

Level

Weight

FAMACHA

Log10

Geometric mean

Log10

Geometric mean

COWP

             
 

  0.0

64.1

2.2

3.11

1283

3.07

1180

 

  0.5

60.6

2.3

2.10

124

1.97

92

 

  1.0

63.5

2.0

2.16

142

1.98

94

 

SEM

3.72

0.15

0.240

 

0.262

 
 

P-value

0.771

0.352

0.012

 

0.011

 

Day

             
 

0

59.0

1.7

2.15

141

2.10

125

 

14

64.0

1.9

1.87

74

1.74

55

 

28

 

2.3

2.85

712

2.71

516

 

42

65.2

2.8

2.93

858

2.80

628

 

SEM

2.19

0.13

0.223

 

0.228

 
 

P-value

<0.001

<0.001

0.001

 

0.001

 

COWP x Day

P-value

0.369

0.079

0.114

 

0.051

 

 

Data from Sheep#2, Sheep#3 2013 and Sheep#5 2014 were analyzed together with the same mixed model using restricted maximum likelihood methods. Table 3 contains means and P values obtained. COWP x Day effect was significant for both SFEC and HFEC. The effect of  COWP x Day was significant for HFEC (P=0.019). The effect of Farm*COWP x Sex x Day was also significant for HFEC. However, this appears to be due primarily to an interaction for one farm. The number of lambs within each cell for this farm were so small that this interaction might actually be caused by the individual effects of lambs nested in treatment. Means for COWP x Day within Farm showed that the primary influence of COWP was in the first sampling period after administration and that in some cases the effect of dosages of 0.5 and 1 g was simply to limit increases in HFEC from Day O to Day 14 as comtared to the CONTROL treatment rather than actually reducing HFEC.

Table 3. Means and P values for fixed effects in analysis pooling Sheep#2, Sheep#3 and Sheep#5 trials

       

Strongyles

Haemonchus

Effect

Level

Weight, kg

FAMACHA

Log10

Geometric mean

Log10

Geometric mean

Farm

BMO

22.3

2.4

3.32

2089

3.26

1807

 

Down

57.7

1.4

2.44

272

2.06

114

 

Stone

63.8

1.8

2.74

554

2.68

481

 

SEM

2.00

0.09

0.091

 

0.100

 
 

P-value

< 0.001

< 0.001

< 0.001

 

< 0.001

 

COWP

  0.0

25.2

1.9

2.89

779

2.78

605

 

  0.5

57.7

1.9

2.81

644

2.60

394

 

  1.0

63.8

1.8

2.80

629

2.62

418

 

SEM

2.00

0.08

0.091

 

0.099

 
 

P-value

0.653

0.626

0.716

 

0.336

 

Sex

F

25.0

1.8

2.71

517

2.54

343

 

M

26.6

1.9

2.95

896

2.80

627

 

SEM

0.6

0.07

0.074

 

0.080

 
 

P-value

0.085

0.131

0.023

 

0.022

 

Day

0

22.7

1.8

2.75

563

2.57

373

 

14

 

1.9

2.82

663

2.68

477

 

28

28.9

2.0

2.93

845

2.75

560

 

SEM

0.45

0.07

0.067

 

0.074

 
 

P-value

< 0.001

0.021

0.060

 

0.116

 

Farm*COWP

P-value

0.256

0.287

0.139

 

0.163

 

Farm*Sex

P-value

0.208

0.218

0.621

 

0.736

 

COWP*Sex

P-value

0.279

0.741

0.773

 

0.588

 

Farm*COWP*Sex

P-value

0.210

0.442

0.829

 

0.579

 

Farm*Day

P-value

< 0.001

< 0.001

< 0.001

 

< 0.001

 

COWP*Day

P-value

0.400

0.433

0.062

 

0.019

 

Sex*Day

P-alue

0.027

0.89

0.555

 

0.335

 

Farm*COWP*Day

P-value

0.914

0.345

0.355

 

0.285

 

Farm*Sex*Day

P-value

0.255

0.389

0.124

 

0.242

 

COWP*Sex*Day

P-value

0.770

0.775

0.129

 

0.279

 

Farm*COWP*Sex*Day

P-value

0.718

0.346

0.084

 

0.047

 

Results for Sheep#1 and Sheep#4 2014

Lambs on these two farms were given 0, 0.5 or 1.0 g COWP at weaning. There were equal numbers of ram and ewe lambs withing each COWP group. Except for a Sex x Day interaction (P < 0.001), where – as expected – rams grew faster than ewes, there were no other effects on weight. The COWP x Sex x Day interaction approached significance (P = 0.052) for FAMACHA scores, which was reflective of the results for fecal egg counts. The COWP x Day interaction (P < 0.001) for strongyle fecal egg counts showed much higher values with increasing days for lambs given 0 COWP than for lambs given 0.5 or 1 g COWP. There was a Farm x COWP x day interaction (P < 0.001) for H. contortus. Lambs from Sheep #4 had zero eggs until day 56 so there was no COWP effect. Lambs from Sheep#1, given either 0.5 or 1 g COWP maintained < 500 e/g throughout the experiment while those given 0 COWP (control) had dramatic increases in eggs to as high as 6,000 e/g at day 42.

Results for Sheep#5 2014 ewes

Ewes in this experiment were given 0, 1, or 2 g of COWP and fecal eggs measured at day 0, 14 and 28. Fecal egg counts were relatively low, ranging from 57 e/g for H. contortus at day 28 to 557 e/g for strongyles at day 0 (geometric means). With such a low level of infection, there was little chance that an effect of COWP could be observed and, in fact, there was neither a COWP x Day interaction nor a direct effect of COWP level. While H. contortus levels declined from 213 to 107 to 85 e/g as COWP level increased from 0 to 1 to 2 g, the variation was too high to be statistically significant. In fact, H. contortus levels declined from 296 e/g at day 0 to 114 e/g at day 14 to 57 e/g at day 28.

Results for Meat goat#1 2014 and Meat goat#2 2015 

Two studies were done using Boer goat kids. Meat goat#1 2014 looked at 24 self weaning doe and wether kids averaging 118 days old when given 0.0, 0.5 or 1.0 g of COWP with adlib access to hay as well as pasture and some concentrate supplementation. Doelings and wethers were equally distributed across COWP treatments. With the exception of the expected significant effects of Day (P=0.000) and Sex*Day (P=0.056; wethers grew faster than doelings over time), there were no statistically significant fixed effects on weight. Only the effect of Day (0.012) was significant for FAMACHA and FAMACHA scores increased over time reflecting the trend also noted in SFEC (P value for Day = 0.000) and HFEC (P value for Day = 0.000). Fixed effects of COWP and COWP*Day were not significant for either SFEC or HFEC. Fixed effects of COW*Sex (P value = 0.032 and 0.030) and COW*Day*Sex (P value = 0.005 and 0.005) were significant for SFEC and HFEC, respectively, indicating that SFEC and HFEC behaved differently for male and female animals on the same COWP treatment over time. However, given the small number of animals per cell this was probably a reflection of individual kid random effects rather than a causal effect of sex. A second general linear model was run looking at the change in untransformed HFEC from Day 0 to Day 14 after COWP dosing (CHG_HFEC).   The effect of COWP was significant (P = 0.13) with increases in H. contortus eggs per gram from Day 0 to Day 14 of 3098 ± 486, 1472± 486 and 864 ± 486 for 0.0 g, 0.5g and 1.0 g of COWP, respectively. The CONTROL treatment was significantly different (P = 0.005) from the 0.5 and 1.0g COWP treatments but they were not significantly different from each other (P=0.388).

The second trial with Boer meat goat kids, Meat goat#2, consisted of 32 kids receiving 0.0g, 0.5 g, 1.0 g and 1.5 g 2 wks pre-weaning when averaging 8 wks. old. The study was carried out for 42 days. Only the fixed effect of Day (P=0.000) was significant for weight and for FAMACHA. The P values for the effect of COWP were 0.053 and 0.196 and for COWP*Day were 0.306 and 0.159 for SFEC and HFEC respectively. Although the effect of COWP was significant for SFEC, observation of the fitted means showed no general trends as COWP dosage increased. Instead ranking of SFEC fitted means from highest to lowest worm egg count was 0.5 g COWP, 1.5 g COWP, 0.0 g COWP and 1.0 g COWP.  The CONTROL animals had the lowest worm counts at the initiation of the study and remained low until Day 28 when the worm challenge became more noticeable for most treatment groups. The CONTROL group did have slightly higher fitted means for SFEC and HFEC on Day 42 than the other COWP treatments but the increase was not significant.

Results from these two studies were disappointing and did not support the hypothesis that dosing with COWP is as effective as chemical dewormers to control H. contortus. In the second study, infection may have been delayed too much to obtain best results from the COWP.  However, meat goat kids in the first study were already well infected at the start of their trial.  Possibly the dosages of COWP need to be higher for meat goat kids. Another explanation is that unidentified factors in herd management were inhibiting the performance of COWP.

Results for Sheep#1 2015

Lambs on this farm were grown on birdsfoot trefoil (BFT) or conventional pasture (CP). Each pasture group was given 0 or 1 g of COWP for a 2 x 2 factorial arrangement of treatments. A fifth group of lambs was barn-fed a hay-grain diet and given 1 g of COWP and had fewer (P = 0.008) strongyle eggs than pasture-fed lambs. There was no effect of pasture type on strongyle eggs, but within pasture types fecal egg counts increased much more dramatically with days on experiment for lambs given 0 COWP compared with lambs given 1 g COWP (P < 0.001).

Average daily gain ranged from 0.3 lb/d for the lambs on the BFT pasture given 1 g COPW to 0.16 lb/d for lambs on CP with the barn-fed lambs in between at 0.26 lb/d. But the SEM was 0.04 lb per day so the overall effect of treatment was not significant.

Results for Meat goat#3 2016

Kids on this farm were grown on birdsfoot trefoil (BFT) pasture or conventional pasture (CP). Half the kids on CP were either given 1 g COWP so the treatments were BFT, CP, CPCOWP. Average weights ranged from 58 lb for those on BFT to 51 lb for those on CPCOWP, with kids on CP at 52 lb (SEM = 3.74), but these differences were not significant. FAMACHA scores were about 2 for all groups. Fecal egg counts for total stongyles were 447, 1663, and 1096 (geometric means for BFT, CP, and CPCOWP, respectively), but the variation was so high that the difference only approached significance (P = 0.083).

Results for Fiber goat#1 2017

The effect of birdsfoot trefoil (BFT) compared with conventional pasture (CP) and 1 g of COWP vs no COWP was compared in kids across 2 breeds in a 2 x 2 x 2 factorial arrangement of treatments across time. Breed had no effect on any responses. There was an effect of pasture type x COWP (P = 0.047) on weight. Kids on the BFT pasture weighed more than kids on CP. Within pasture type, however, COWP had opposite effects; kids given no COWP on BFT weighed slightly less than kids given COWP on BFT, but kids given no COWP on CP weighed 4 lb more than kids given COWP on CP. FAMACHA scores were not significantly affected by pasture type or COWP. While pasture type had no effect on total strongyle fecal egg counts, COWP decreased (P = 0.054) them from 1217 e/g to 389 e/g (geometric means). COWP had a similar effect (P = 0.004) on fecal egg counts for H. contortus, decreasing them from 1139 to 152 e/g (geometric means).

Research conclusions:

The effectiveness of COWP to reduce H. contortus was variable among farms in the study. The results of the majority of our studies did not support the hypothesis that COWP use is as effective as chemical anthelmintics to control H. contortus. Dosing with COWP was very effective for 3 years in a row at one farm, showed significant short term effects at some farms, and was of no value in reducing worm loads on other farms. Further investigation is warranted to explain the farm-to-farm variability. However, in cases where COWP was effective, low dosages often preformed as effectively as higher dosages.

The mechanism by which COWP controls barber pole worm (H. contortus) is not well understood. When the copper oxide wire particles become embedded in the wall of the true stomach (abomasum), the acidity of the abomasum makes the copper in the wires soluble and it is slowly released into the abomasum where barber pole worms reside.  Thus, the release of copper in the abomasum from embedded COWP may directly damage and kill the worms as evidenced by the presence of worm lesions in some studies. However, copper is also a key component of the immune system. Thus, copper released in the abomasum is absorbed by the animal’s body through the intestines and may trigger a more sensitive, rapid and/or effective immune response to H. contortus infection. Anything that influences the embedding or acid solubilization of the COWP will therefore impact its ability to reduce H. contortus infection.

Refined studies that track the progress of COWP through the digestive track under well controlled and varied management conditions may assist researchers to better identify the management practices contributing to COWP effectiveness. The copper in COWP becomes insoluble at pH > 3.4. What sort of diets best promote the embedding of COWP in the abomasum and best maintain sufficient acidity in the abomasum to permit acid solubilization? How do stress and sudden changes in diet disrupt these activities? If farms have a long history of supplementing copper through feed concentrates or minerals, how does this effect the vulnerability of the worm population to copper release in the abomasum? Are there methods to encourage the esophageal groove to open when administering COWP orally so that the COWP bypasses the rumen and is directly shunted to the abomasum?

Given the variable responses of parasitic worms to COWP dosing at different farms, it is difficult to predict whether COWP will control H. contortus in specific herds or flocks. Until the factors influencing COWP effectiveness are better identified, farmers should monitor animals after COWP dosing to evaluate whether dosing is effective to control or reduce H. contortus infection in their herds. 

Our studies indicate that on farms where COWP is effective, it does not need to be given at the higher dosages recommended in some online blogs or livestock catalogs. Dosages of 0.5 g/head were as effective as 1 g dosages in lambs and 2 g/head dosages were as effective as 1 gram/22 lb live weight dosages in adult lactating does. We were unable to make conclusions for goat kids or mature ewes. Researchers recommend low dosages because the detrimental effect of COWP on barber pole worm is short lived and in a sustainable Integrated Parasite Management (IPM) program may need to be repeated multiple times over the grazing period. In addition, some studies in the Southeast have indicated that barber pole worms could become resistant to COWP. Therefore in agreement with Southeast researchers, we envision farmers using COWP as part of a FAMACHA or 5 point check program.  For example, conventional farms might give COWP to lambs and kids scoring “3” while more anemic animals scoring “4” or “5” would be dewormed with an effective dewormer. 

Farmers should not administer COWP without incorporating other important aspects of an IPM program such as selectively treating animals and practicing evasive parasite grazing management. Farmers need to keep in mind that COWP is considered effective only against barber pole worm and that in the presence of brown stomach worm (Teladorsagia circumcincta) infections, the pH of the abomasum may increase and render the COWP insoluble thus making it ineffective as either a copper supplement or barber pole worm control.

Participation Summary
10 Farmers participating in research

Education

Educational approach:

This project included an extensive educational program on strategic control of internal parasites. Farmers were recruited to participate in the program through direct mailings from our data base of more than 3,000 people engaged in various aspects of sheep and/or goat farming, through Cornell Sheep and Goat Program list servers, and through their local Cooperative Extension offices and farmer associations. Service providers and livestock educators were also directly addressed through presentations at in-service trainings and meetings of veterinarians participating in the NYS Sheep and Goat Health Assurance Program.

The educational program emphasized the methods suggested by the American Consortium for Small Ruminant Parasite Control. Farmers and extension educators were trained in integrated parasite management through workshops covering the FAMACHA system and selective deworming, evasive grazing management techniques, and recent research results to minimize anthelmintic resistance. Specifically, workshops emphasized parasitic life cycles, detection of infection, hands-on fecal egg counting, specific pasture grazing and rest intervals to evade or avoid excessive parasite infection, and hands-on practice with the FAMACHA system and 5 point checks. Preliminary results from our research on 1) the use of COWP to control H. contortus infection, 2) P. tenuis (deer worm) control and treatment, and 3) the use of high tannin varieties of Birdsfoot trefoil to control H. contortus (in cooperation with several other universities) were integrated into our trainings and presentations. Information from other universities on alternative methods of parasite control was also incorporated into the workshops. In addition to field days on farms directly participating in our COWP and BFT experiments, the project is developing paper and web-based bulletins on practical methods for control of H. contortus and P. tenuis. We have initiated a web site, Cornell University Small Ruminant Parasite Research http://blogs.cornell.edu/smallruminantparasites/, to share preliminary resources from the on-farm studies and to support farmers and livestock educators with access to training materials. 

Milestones

Milestone #1 (click to expand/collapse)
What beneficiaries do and learn:

Three-thousand sheep and goat farmers learn about this research and extension project and are directed to an on-line survey about their methods of controlling H. contortus (barber pole worm) and other internal parasites.

Proposed number of farmer beneficiaries who will participate:
3000
Actual number of farmer beneficiaries who participated:
1200
Proposed Completion Date:
June 30, 2014
Status:
Completed
Date Completed:
June 30, 2014
Accomplishments:

Although our database of Northeast sheep and goat farmers contains over 3000 entries, invalid emails and further mis-identification of the email invitation as spam resulted in about 1200 addresses receiving the announcement. Thus,1200 farmers received news about the research and extension opportunities proposed for this project.

 

 

Milestone #2 (click to expand/collapse)
What beneficiaries do and learn:

Two-hundred farmers attend field days, workshops at regional conferences, or extension programs to learn directly about control of H. contortus and other internal parasites using COWP and other methods, such as FAMACHA scoring, evasive pasture management, and forages high in condensed tannins.

Proposed number of farmer beneficiaries who will participate:
200
Actual number of farmer beneficiaries who participated:
1248
Proposed Completion Date:
November 30, 2017
Status:
Completed
Date Completed:
November 30, 2017
Accomplishments:

More than 1200 farmers, interns, veterinarians, service providers, and educators participated in the project’s integrated parasite management workshops, field days and presentations.  Where pre- and post-questionnaires  were administered, responses indicated that participants improved their knowledge of parasite management and that at least half of participants planned changes in parasite management related to selective deworming, evasive grazing or testing out alternative methods of parasite control being studied in the project. Participation in the project’s IPM/FAMACHA workshops resulted in 460 farmers, interns, service providers, and agricultural educators (not including 49 university students who are not actively farming or consulting yet) becoming certified in FAMACHA. Approximately 685 farmers provided follow up contact information to track their parasite management changes.

Milestone #3 (click to expand/collapse)
What beneficiaries do and learn:

Twelve farmers agree to do the research with COWP. Seven farmers carry out the research and get first hand experience with oral dosing of COWP.

Proposed number of farmer beneficiaries who will participate:
7
Actual number of farmer beneficiaries who participated:
10
Proposed Completion Date:
November 30, 2017
Status:
Completed
Date Completed:
November 30, 2017
Accomplishments:

Ten farmers participated in 13 on-farm trials evaluating the effects of oral dosing with COWP on H. contortus (barber pole worm) infections in goats and sheep. Three studies combined the use of COWP dosing with Birdsfoot trefoil grazing for internal parasite control. Farmers and farm interns gained first-hand experience with FAMACHA scoring and fecal sampling. The research was onerous for some. Most farmers observed that responses to dosing with COWP were more variable than when animals are dewormed with an effective dewormer, assuming that there are still dewormers effective in their flock or herd.  

Milestone #4 (click to expand/collapse)
What beneficiaries do and learn:

One-hundred participating farmers respond to follow up questionnaires or interviews on changes made in internal parasite management. these questionnaires provide farmers with an opportunity to step back and evaluate what changes they have actually implemented.

Proposed number of farmer beneficiaries who will participate:
100
Actual number of farmer beneficiaries who participated:
138
Proposed Completion Date:
November 30, 2017
Status:
Completed
Date Completed:
November 30, 2017
Accomplishments:

Invitations to complete a follow up survey summarizing any resulting changes in parasite management were sent to 553 workshop participants. One hundred and seventy participants representing NY (62%), VT (17%), MA (6%), PA (5%), CT, NH, NJ, OH, ON, QC and RI responded to the survey with 138 respondents completing it entirely. We had planned to send out the survey again in late summer 2017. However, we were analyzing data and conducting workshops until fall 2017 and were unable to send out a survey announcement.  We do plan to send out a survey this winter to try and track additional changes by workshop/field day participants.

Milestone Activities and Participation Summary

Educational activities:

2 Curricula, factsheets or educational tools
13 On-farm demonstrations
1 Online trainings
3 Published press articles, newsletters
34 Webinars / talks / presentations
33 Workshop field days
3 presentations at in-service trainings for livestock educators or state veterinarians

Participation Summary:

1200 Farmers
40 Number of agricultural educator or service providers reached through education and outreach activities

Learning Outcomes

268 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation

Performance Target Outcomes

Target #1

Target: number of farmers:
75
Target: change/adoption:

Deworming less

Target: amount of production affected:

reduce death rate from as much as 18% to 5% for a flock of 100 mature females (death rate would include young stock)

Target: quantified benefit(s):

Reduce chemical dewormer cost by $215 and increase income by $2205 (due to reduced death rate) for a flock of 100 mature females (deworming would include young stock)

Actual: number of farmers:
93
Actual: change/adoption:

Sixty two respondents indicated that they adopted FAMACHA alone or in combination with a 5 point check to selectively deworm animals as a result of our programs while 21 respondents indicated they already used these practices and made no change, 31 improved on these practices and 6 planned to adopt soon.

When asked if they reduced their use of synthetic dewormers as a result of practices they adopted or improved upon because of our programs, 46% (52 farmers) said “yes”, 31% (35 farmers) were unsure and 24% (27 farmers) said “no” either because of no reduction or because of already reducing or eliminating use. Annual savings in dewormer costs reported by respondents because of adoption of the recommended practices ranged from $30 to $500, averaging $143.

Actual: amount of production affected:

About a third of the farmers indicated that they had seen an improvement in animal health and/or performance as a result of adoption of these practices. However, only a few were able to estimate a dollar value for these improvements.

Seven, ten, and five farmers, respectively, gave monetary values for 1) earnings from improved animal productivity ranging from $100 to $1400 (average $557), 2) savings in health costs (vet bills, labor to treat parasitized animals) ranging from $100 to $1000 (average $300), and 3) savings from reduced animal mortality from parasites ranging from $400 to $2000 (average $1180).

Twelve farmers reported feeling more confident about their transition to organic small ruminant production because of practices they adopted from attendance at our programs while 62 farmers indicated that they have no plans to be organically certified but have increased confidence in managing gastrointestinal parasites without regular use of synthetic dewormers. About 71% of respondents planning to start raising goats/sheep also reported increased confidence and 71% of veterinarians and educators felt more confident in advising goat and sheep farmers on parasite management.

Actual: quantified benefit(s):

Annual savings in dewormer costs reported by 52 respondents because of adoption of the recommended practices ranged from $30 to $500, averaging $143.

Performance Target Outcome Narrative:

One hundred and seventy participants representing NY (62%), VT (17%), MA (6%), PA (5%), CT, NH, NJ, OH, ON, QC and RI responded to a 41 question follow up survey with 138 respondents completing it entirely. Sixty two respondents indicated that they adopted FAMACHA alone or in combination with a 5 point check to selectively deworm animals as a result of our programs. While 21 respondents indicated they already used these practices and made no change, 31 improved on these practices and 6 planned to adopt them soon.

When asked if they reduced their use of synthetic dewormers as a result of practices they adopted or improved upon because of our programs, 46% (52 farmers) said “yes”, 31% (35 farmers) were unsure and 24% (27 farmers) said “no” either because of no reduction or because of already reducing or eliminating use. Annual savings in dewormer costs reported by respondents because of adoption of the recommended practices ranged from $30 to $500, averaging $143.

About a third of the farmers indicated that they had observed an improvement in animal health and/or performance as a result of adoption of these practices. However, only few were able to estimate a dollar value for these improvements.

Seven, ten, and five farmers, respectively, gave monetary values for 1) earnings from improved animal productivity ranging from $100 to $1400 (average $557), 2) savings in health costs (vet bills, labor to treat parasitized animals) ranging from $100 to $1000 (average $300), and 3) savings from reduced animal mortality from parasites ranging from $400 to $2000 (average $1180).

Twelve farmers reported feeling more confident about their transition to organic small ruminant production because of practices they adopted from attendance at our programs while 62 farmers indicated that they have no plans to be organically certified but have increased confidence in managing gastrointestinal parasites without regular use of synthetic dewormers. About 71% of respondents planning to start raising goats/sheep also reported increased confidence and 71% of veterinarians and educators felt more confident in advising goat and sheep farmers on parasite management.

93 Farmers changed or adopted a practice
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.