FAMACHA© vs PRODUCTION :

What Is The Score?

FAMACHA© vs PRODUCTION :

What Is The Score?

Department of Veterinary Tropical Diseases

University of Pretoria, South Africa

Department of Veterinary Tropical Diseases

University of Pretoria, South Africa

J.A. van Wyk J.A. van Wyk

Can farmer

live with

Targeted

Selective

Treatment

?

WILL THERE BE PRODUCTION

LOSSES, & IF SO, ARE THEY

RECONCILABLE WITH

PROFITABLE FARMING

ENTERPRISE ?

YES losses to be expected (Van Wyk & Bath 2002)

• For Targeted Selective TreatmentFAMACHA©

Body Condition ScoringDag Score, or whatever…

BUT

• Degree of challenge pivotal; and• Total effect on production to determine

outcome

HOWEVER, many factors can play a role

Such as :

• Worm species• Age, class, breed of host• Susceptibility of worm population• Level of worm challenge• Level Of FAMACHA© application

Level of FAMACHA © application

• Frequency of examination of herd

(the more frequent, the safer)• Proportion of animals examined• FAMACHA © categories treated Fixed In relation to worm challenge

Level of FAMACHA© application : Ours relatively “harsh”

• Mostly fixed FAMACHA© category(not adjusted according to mounting anaemia)

• Often too infrequent• Ignored faecal egg counts• Thus animals seriously challenged

Production trials

1. Farm 1

Trial 1: Replacement rams + wether tracers

Trial 2: Replacement ewes

2. Farm 2

Trial 3: Replacement ewes

However, various problems with trial design

Problems with trial design (MONEY, MONEY, MONEY)

• Nutrition more important than wormsNo two pastures identical (esp. if large), e.g.

Nutrition (type and stance of herbage)

Worm infectionHost grazing habitsHost susceptibilitySlope

• Therefore several replicates essential Almost always small Therefore few animals per paddock Need many paddocks

SOUTH AFRICA :

• 15 % of land arable(only 15 % of which good arable)

• Natural pasture very variable(grass, small bushes, shrubs, trees)

• Acute funding problem

“Fortunately” some farmers desperate due to drug resistance

TRIAL DESIGN

“Side-stepped” problems (partially)

– Single, quite large flock (> 150)– Common pasture for different trial

treatment groups

Disadvantages of design

• Treatments affect one another

“Excessive” contamination on one hand“Depletion” of L3 on the other

• Only suppressive vs selective treatment feasible (no “conventional” treatment groups, due to contamination by other groups)

Production trials

1. Farm 1

Trial 1: Replacement rams + wether tracers

Trial 2: Replacement ewes

2. Farm 2

Trial 3: Replacement ewes

Farm 1 (Experiment 1 & 2)

Pasture – Mostly natural grassland + little improved (kikuyu)– Generally reasonably flat– Rotational grazing (± too short for much worm control)– All flocks on farm share same pastures in rotation

Sheep– Stud Merino – ±1500 on farm– 30 inches rain p/a (summer, ± well distributed)

Worm species– H. contortus predom. (+ Trich .& Ost. problems autumn)– Fasciola hepatica a problem periodically

Drug resistance (± relief from artificial dilution)

Experiment 1 - Highest individual faecal egg counts of the FAMACHA©-treated sheep

DATESheep (n) in high egg count ranges

TOTAL > 40004-

6 0006-

9 0009-

12 00012-

20 000>

20 000

18 Dec

12 Jan23 Jan29 Jan

19 Feb

23231

45221

00253

00239

00025

688

1519

TOTAL 11 14 10 14 7 56

DATE MEAN WORM EGG COUNT PER GROUP

GROUP DOSING PARTICULARS *

FAMACHA SUPPRESSIVE GROUP INTER-VAL (d)

07 Nov 17 Nov 27 Nov 8 Dec 18 Dec 12 Jan 29 Jan 19 Feb 12 Mar 22 Mar 3 Apr 23 Apr14 May 4 Jun 27 Jun

756 75 216 757 301 3 795 8 452 15 112 0 67 283 158 295 1 683 83

236 78 157 169 370 17 728 288 4 0 125 46 260 2 142 50

Both (7 Nov)-Suppr (30 Nov)-Suppr (18 Dec)Suppr (8 Jan)Suppr (19 Jan)**Suppr (19 Feb)Both (8 Mar)-Both (9 Apr)--Both (4 Jun)-

n/a-

23-8

21113116-

32--

56-

Exp. 1: Mean faecal worm egg counts per group of sheep, plus dates on which all groups were drenched

* Shifted to the closest date on which egg counts were done** Only half of the suppressive group treated

Farm 1 (Experiment 1)

NOTE: Experiment was “stopped” at the peak of the worm season, by

drenching all the animals in both groups when worm challenge was excessively severe

Experiment 1 - Body mass

MEAN BODY MASS

22.00

24.00

26.00

28.00

30.00

32.00

34.00

36.00

EVALUATION INTERVAL

FAMACHA

SUPPRESSIVE

Experiment 1 - Highest individual faecal egg counts of the FAMACHA©-treated sheep

DATESheep (n) in high egg count ranges

TOTAL > 40004-

6 0006-

9 0009-

12 00012-

20 000>

20 000

18 Dec

12 Jan23 Jan29 Jan

19 Feb

23231

45221

00253

00239

00025

688

1519

TOTAL 11 14 10 14 7 56

MEAN BODY CONDITION SCORE

2.20

2.30

2.40

2.50

2.60

2.70

2.80

2.90

3.00

3.10

EVALUATION INTERVAL

FAMACHA

SUPPRESSIVE

Experiment 1 : Body Condition Score

MEAN FAMACHA SCORE

0.80

0.90

1.00

1.10

1.20

1.30

1.40

1.50

EVALUATION INTERVAL

FAMACHA

SUPPRESSIVE

Exp. 1 FAMACHA© score

DATE MEAN F.E.C. PER GROUP

FAMACHA© SUPPRESSIVE

07 Nov 17 Nov 27 Nov 8 Dec 18 Dec 12 Jan 29 Jan 19 Feb 12 Mar 22 Mar 3 Apr 23 Apr14 May 4 Jun 27 Jun

756 75 216 757 301 3 795 8 452 15 112 0 67 283 158 295 1 683 83

236 78 157 169 370 17 728 288 4 0 125 46 260 2 142 50

Exp. 1: Mean FECs per trial group

Production trials

1. Farm 1

Trial 1: Replacement rams + wether tracers

Trial 2: Replacement ewes

2. Farm 2

Trial 3: Replacement ewes

Farm 1 (Experiment 1 & 2)

pasture – Mostly natural grassland + little improved (kikuyu)– Generally reasonably flat– Rotational grazing (± too short for worm control)

Sheep– Stud Merino only– ±1500 on farm– 30 inches rain p/a (summer, ± well distributed)

Worm species– H. contortus predom. (+ Trich .& Ost. problems autumn)

Drug resistance (± relief from artificial dilution)

Worm egg count

Sheepn %

> 15 0009 000-14 9005 000-8 9003 000-4 900

< 3 000

2534242134

1825171525

Exp. 2: FECs - “FAMACHA©-treated sheep

DATEMEAN FAECAL EGG COUNTS

FAMACHA© SUPPRESSIVE

11 Nov 7 Jan17 Jan 3 Febr 8 Febr 9 Apr25 Apr

1665774834584180155236929

26871314-

13369133

Exp. 2: Mean FECs

Farm 1 (Experiment 2)

NOTE: Experiment was “stopped” at the peak of the worm season, by

drenching all the animals in both groups when worm challenge was excessively severe

MEAN FAMACHA SCORE

0.90

1.00

1.10

1.20

1.30

1.40

1.50

1.60

1.70

16-O

ct

5-N

ov

25-N

ov

15-D

ec

4-Ja

n

24-J

an

13-F

eb

5-M

ar

25-M

ar

14-A

pr

4-M

ay

24-M

ay

EVALUATION INTERVAL

FAM

AC

HA Flock

Suppressive

Famacha

Exp. 2 - Mean FAMACHA© score

MEAN MASS

24.0

26.0

28.0

30.0

32.0

34.0

36.0

38.0

9-N

ov

23-N

ov

7-D

ec

21-D

ec

4-Ja

n

18-J

an

1-F

eb

15-F

eb

1-M

ar

15-M

ar

29-M

ar

12-A

pr

Weighing Intervals

ME

AN

MA

SS

Flock

Suppressive

Famacha

Exp. 2 - Mean live mass

Remember :

SUPPRESSIVE

versus

SELECTIVE

treatment

MEAN BODY CONDITION SCORE

2.20

2.30

2.40

2.50

2.60

2.70

2.80

2.90

3.00

3.10

3.20

EVALUATION INTERVAL

Flock

Suppressive

Famacha

Exp. 2 - Mean Body Condition Score

MEAN MASS

24.0

26.0

28.0

30.0

32.0

34.0

36.0

38.0

9-N

ov

23-N

ov

7-D

ec

21-D

ec

4-Ja

n

18-J

an

1-F

eb

15-F

eb

1-M

ar

15-M

ar

29-M

ar

12-A

pr

Weighing Intervals

ME

AN

MA

SS

Flock

Suppressive

Famacha

Comment: Why did FAMACHA© “flock” & “monitor” groups differ so after all had been treated, while

design was similar for both groups (only anaemic sheep drenched beforehand)

Production trials

1. Farm 1

Trial 1: Replacement rams + wether tracers

Trial 2: Replacement ewes

2. Farm 2

Trial 3: Replacement ewes

Farm 2 (Experiment 3)

pasture – Only natural grassland – Generally reasonably flat– Rotational grazing (± too short for much effect on worm)– All flocks on farm share same pastures in rotation

Sheep– Commercial Merino only– ±1200 on farm– 20 inches rain p/a (summer, more erratic than farm 1)

Worm species– H. contortus practically only roundworm– Fasciola hepatica a problem periodically

No appreciable drug resistance

DATE MEAN FAECAL EGG COUNTS

FAMACHA© SUPPRESSIVE

10 Jan 27 Febr 10 Apr 15 May

33002086600700

003

58

Exp. 3: Mean faecal egg counts of “FAMACHA©” & “SUPPRESSIVE” groups (n = 48/group)

EGGS/g FAECES SHEEP (n)

>90006 000-8 9004 000-5 900

236

Maximum fec (10 Jan): 15 400 epg

Exp. 3: Largest individual faecal egg counts (Jan. & Feb.) – Eggs per gram of faeces

Farm 2 (Experiment 3)

NOTE: Experiment not “stopped” at the peak of the worm season, by drenching all the animals in both groups at the peak of the worm challenge

Mean body mass

30.00

32.00

34.00

36.00

38.00

40.00

42.00

44.00

Date of weighing

Me

an

ma

ss

FAMACHA

SUPPRESSIVE

Exp. 3 - Mean live mass

Mean body mass

30.00

32.00

34.00

36.00

38.00

40.00

42.00

44.00

Date of weighing

Me

an

ma

ss

FAMACHA

SUPPRESSIVE

Comment: Note initial difference between trial groups after randomisation by farmer as the sheep passed through the race

Mean Condition Score

2.60

2.65

2.70

2.75

2.80

2.85

2.90

2.95

3.00

3.05

3.10

Evaluation interval

Mea

n B

CS

FAMACHA

SUPPRESSIVE

Exp. 3 - Mean Body Condition Score

Mean FAMACHA Score

1.00

1.10

1.20

1.30

1.40

1.50

1.60

1.70

1.80

Evaluation interval

ME

AN

FA

MA

CH

A

FAMACHA

SUPPRESSIVE

Exp. 3 - Mean FAMACHA© score

But the trials are flawed!But the trials are flawed!

So what! So what!

Criticism of trials

• “Farmer” trials (e.g. timing, randomisation) [but: carefully done (e.g. BLUP Farm 1)

• Suppressively-treated sheep remove L3 & challenged L3 [but: pastures used optimally & shared other flocks]

• Not possible to test conventional control systems

TREAT-AND-MOVE TO SAFE PASTURETREAT-AND-MOVE TO SAFE PASTURE

RR – 0,01%RR – 0,01%

SR/RS – 10%SR/RS – 10%

SS – 90%SS – 90%

PASTURE 1 PASTURE 2PASTURE 1 PASTURE 2

* * RR – 100%RR – 100%

* Frequency of the allele R on pasture 2 is 100%* Frequency of the allele R on pasture 2 is 100%

No refugiaNo refugia

MOVE-AND-TREAT ON NEW PASTUREMOVE-AND-TREAT ON NEW PASTURE

RR – 0,01%RR – 0,01%

SR/RS – 10%SR/RS – 10%

SS – 90%SS – 90%

PASTURE 1 PASTURE 2PASTURE 1 PASTURE 2

* Frequency of allele R on pasture 2 is 0,01%* Frequency of allele R on pasture 2 is 0,01%

** RR – 0,01% RR – 0,01%

SR/RS – 10%SR/RS – 10%

SS – 90%SS – 90%

REFUGIAREFUGIA

(Molento, Van Wyk & Coles, 2004)(Molento, Van Wyk & Coles, 2004)