FAMACHA© vs PRODUCTION : What Is The Score? FAMACHA© vs PRODUCTION : What Is The Score? Department of Veterinary Tropical Diseases University of Pretoria,
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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)
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