Improvement of technical results by the use of Ingelvac CircoFLEX®
in a Dutch organic breeding and fattening farm: a case report
Abstract
Porcine Circovirus type 2 (PCV2) is a ubiquitous infection and a major cause of production
loss for the pig industry. The aim of this study was to evaluate the effect of vaccination
against PCV2 on technical results of pigs on an organic breeding and fattening farm,
focussing on growth of weaned pigs and mortality and growth of fattening pigs.
The study farm was an organic farm with 170 sows and on average 1,100 fattening pigs.
The study was carried out retrospectively between January 2009 and May 2011. During the
study period three subsequent vaccination strategies were used:
1. Stellamune One shot®, 2. Stellamune One shot® + Ingelvac CircoFLEX®, 3. Ingelvac
MycoFLEX® + Ingelvac CircoFLEX®.
From these three periods the corresponding management data and slaughterhouse data
were analysed by an ANOVA test. Due to few data in period 2 and an outbreak of
Actinobacillus pleuropneumoniae during study period 2 and 3, these two periods were
combined in one period and analysed by a two-sample t-test.
The mortality of weaned piglets decreased with 3.59% (0.62 – 6.55%) (P 0.023) in
comparison to period 1. Average daily weight gain (grams) of weaned piglets (6 – 12 weeks
old) improved by 20.67 (7.40 – 33.94 gram) (P 0.004) in periods 2 and 3. Mortality of
fattening pigs was 2.32% (1.19 – 3.45%) (0.001) then in period 1. Corrected energy
conversion rate of fattening pigs improved 0.27 (0.05 – 0.49) (P 0.017). There was no
significant effect on slaughterhouse parameters.
In conclusion, vaccination against PCV2 improved technical results of weaned and fattening
pigs on this particular farm. The advantage of vaccination with CircoFLEX® + MycoFLEX® in
comparison with the Stellamune® + CircoFLEX® vaccination is that the two vaccinations can
be mixed and administered as a one shot vaccine. This means less work for the farmer and
more animal welfare.
1
Introduction
Porcine Circovirus type 2 (PCV2) is recognized as the essential causative agent of the
disease complex called postweaning multisystemic wasting syndrome (PMWS).
The virus is transmitted via direct and vertical contact (Grau-Roma et al., 2011; Opriessnig et
al., 2007). The oronasal route is considered the most important route of transmission, but the
virus can also be shed in nasal, tonsillar, bronchial and ocular secretions and in faeces,
saliva, urine and semen (Grau-Roma et al., 2011).
The pathogenesis of a PCV2 infection is still not fully understood, but lymphoid depletion and
lymphopenia in peripheral blood are consistent features (Opriessnig et al., 2007).
PMWS has a variety of clinical manifestations, like systemic infection, respiratory disease,
enteritis, reproductive failure and porcine dermatitis and nephropathy syndrome (Martelli et
al., 2011; Opriessnig et al., 2007).
Mostly pigs from two to four months old are affected (Grau-Roma et al., 2011). In weaned
piglets the major symptom is wasting and minor symptoms include respiratory signs,
diarrhoea, paleness of the skin and icterus. In postweaning and early finishing pigs there is
an increase of the mortality due to secondary bacterial infections (Chae, 2004).
PMWS is often seen in combination with other pathogens, such as porcine reproductive
respiratory syndrome virus, swine influenza virus, porcine parvovirus, Haemophilus parasuis,
Actinobacillus pleuropneumoniae, Streptococcus suis and Mycoplasma hypopneumoniae.
These combinations of infections may complicate the clinical presentation (Chae, 2004;
Opriessnig et al., 2007).
In order to control PCV2 it is possible to vaccinate the pigs or sows. Vaccination reduced the
incidence of PMWS and improved average daily weight gain (Grau-Roma et al., 2011;
Fachinger et al., 2008) and feed conversion ratios (Grau-Roma et al., 2011). Further,
vaccination decreased mortality rates (Kixmöller et al., 2008; Kristensen et al., 2011; Martelli
et al., 2011).
The aim of this study was to evaluate the effect of vaccination against PCV2 on technical
results of pigs on an organic breeding and fattening farm, focussing on growth of weaned
pigs and mortality and growth of fattening pigs.
2
Materials and methods
The study was carried out retrospectively on an organic farm with 170 sows and on average
1,100 fattening pigs.
The most important features of this organic farm were that the piglets were weaned on six
weeks of age and that all animals had outside space. The inside and outside space was
divided by plastic flaps, that were bitten on and broken off by the pigs. This made it difficult to
regulate the climate inside the stable.
In the first week of life the piglets were routinely treated against coccidiosis (Toltrazuril®) and
boars were castrated. Pigs entered the fattening unit at twelve weeks of age.
A constant factor during the whole study period was an on-going renovation of the stables.
The farm consisted of two stables, one for the fattening pigs and the other for sows, piglets
and weaned piglets. The weaned piglets were housed in seven compartments with around
40 piglets per compartment. Fattening pigs were housed in a separate stable with ten
compartments with around 40 till 50 fattening pigs per compartment.
The study comprised of three time periods in which different vaccinations against
Mycoplasma hyopneumoniae (M. Hyopneumoniae) and PCV2 were used (Table 1 and Table
2).
Period
Time
Pathogen
January 2009 –
M. hyopneumoniae
1
July 2009
August 2009 –
M. hypopneumoniae
2
February 2010
PCV2
March 2010 –
M. hypopneumoniae
3
May 2011
PCV2
Table 1: vaccination schedule.
Vaccin
Stellamune®
Age at vaccination
1 week
Stellamune®
CircoFLEX®
MycoFLEX®
CircoFLEX®
1 week
3 week
3 week
3 week
Stellamune® was used since 2007 and administered in the first week of life. In August 2009 it
was combined with a vaccination against PCV2 in the third week of life due to poor technical
results of fattening pigs. The farmer reported high mortality of weaned piglets and fattening
pigs, low average daily weight gain and high energy conversion rate in the period preceding
vaccination against PCV2. Further there were a lot respiratory problems, biting of the tail and
wasting.
In March 2010 the farmer switched to the combination of CircoFLEX® + MycoFLEX®,
because it was possible to mix these vaccines and administer it as a one shot vaccine at
twenty-one days of age.
3
Period
1
2
3
January 2009
February 2009
March 2009
April 2009
May 2009
June 2009
July 2009
August 2009
September 2009
October 2009
November 2009
December 2009
January 2010
February 2010
March 2010
April 2010
May 2010
June 2010
July 2010
August 2010
September 2010
October 2010
November 2010
December 2010
January 2011
February 2011
March 2011
April 2011
May 2011
# Weaned
piglets
# Weaned
piglets
# Fattening
pigs
(mortality)
(ADWG)
(mortality)
345
562
442
271
447
500
295
389
337
217
337
362
336
414
376
238
309
335
304
467
343
484
342
301
214
455
3,588
2,280
3,554
345
562
442
271
447
500
295
389
337
217
337
362
336
414
376
238
309
335
304
467
343
484
342
301
214
455
3,805
2,372
3,539
294
1021
935
971
958
1033
1151
1118
1124
1105
1023
978
965
967
960
1034
1109
1155
1089
1151
1103
1185
1204
1281
1303
1205
1238
1110
1067
955
12,382
7,465
12,928
# Fattening pigs
(ADWG)
(Muscle thickness)
(Fat thickness)
(Corrected ECR)
(Days from entrance to
finishing the fattening
unit)
(Pleuritis)
(Rejected livers)
(Affected lungs)
1021
935
971
958
1033
1151
1118
13,349
1124
1105
1023
978
965
967
960
1034
1109
1155
7,601
1089
1151
1103
1185
1204
1281
1303
1205
11,825
1238
1110
1067
955
Table 2: Explanation of the cut-off points: time schedule of the different vaccination periods.
The numbers in the table represent the number of pigs included in the study period in a
certain month for a parameter.
ADWG: average daily weight gain; ECR: energy conversion rate
Period 1
Stellamune One shot®
Period 2
Stellamune One shot® + Ingelvac CircoFLEX®
Period 3
Ingelvac MycoFLEX® + Ingelvac CircoFLEX®
4
Parameter choice
Mortality weaned piglets (%):
Piglets were weaned at six weeks of age and entered the fattening unit when they were
twelve weeks old. When a group of piglets was introduced in the nursery there were two
other age groups present (nine weeks old and twelve weeks old), since this farm has a threeweek system.
Mortality of weaned piglets was included in a study period when two of the three groups were
of the same study period. This is the case approximately six weeks after vaccination.
Average daily weight gain (gram) of weaned piglets:
This parameter was calculated for twelve week old piglets, which could be sold or entered
the fattening unit.
Average daily weight gain of weaned piglets was included in a study period when
approximately all three groups were of the same study period. This is the case approximately
nine weeks after vaccination.
Mortality fattening pigs (%):
Pigs entered the fattening unit at twelve weeks of age and stayed there on average 121 days
(seventeen weeks).
Mortality of fattening pigs was included in a study period when half of the pigs in the fattening
unit were of the same study period. This was after 60.5 days (8.5 weeks) in the fattening unit
and so approximately 17.5 weeks after vaccination.
Average daily weight gain (gram) of fattening pigs, muscle thickness (mm), fat thickness
(mm), corrected energy conversion rate of fattening pigs, days from entrance to finishing the
fattening unit and slaughterhouse parameters (% pleuritis, % rejected livers, % affected
lungs):
The average number of days from entrance to finishing the fattening unit was 121 (seventeen
weeks).
The above parameters were included in a study period when approximately all pigs were of
the same study period. This was the case after approximately 26 weeks (nine weeks as
piglet plus seventeen weeks in the fattening unit).
Data in the management program of the farmer (Farm®; Agrovision) and slaughterhouse data
were routinely analysed with a frequency of once per month.
The management program was used by the farmer to register technical results of the farm,
like mortality and weight, based on calculation rules.
The slaughterhouse data provided information about the muscle thickness (mm), fat
thickness (mm), pleuritis (%), rejected livers (%) and affected lungs (%). These parameters
represent the average of all pigs slaughtered in one month.
5
Statistical analysis
Statistical analyses of the data were performed using an ANOVA with post-hoc Bonferroni
and a two-sample t-test in SPSS 18. When Levene’s test for equality of variances was
significant a nonparametric test was performed. In case of the ANOVA this was the KruskalWallis test and for the two-sample t-test a Mann-Whitney test.
The data were checked for seasonal effects using a two-sample t-test. The twelve months of
a year were divided in six ‘warm’ months (April till September) and six ‘cold’ months (October
till March). When present, a regression model was used to check for confounding by season.
6
Results
The two-sample t-test was only significant for corrected energy conversion rate of fattening
pigs (P 0.005). In a regression model with only season in it, β was 2.762 and in a regression
model with season and corrected energy conversion rate β was 3.024. The difference in β is
0.262 (10.54%).
The results of the ANOVA with the mean and 95% confidence interval of the different
parameters are summarized in
Table 3.
Parameter
Mortality weaned
piglets (%)
Average daily
weight gain (gram)
of weaned piglets
Mortality fattening
pigs (%)
Average daily
weight gain (gram)
of fattening pigs
Muscle thickness
(mm)
Fat thickness (mm)
Corrected energy
conversion rate
fattening pigs
Days from entrance
to finishing the
fattening unit
Pleuritis (%)
Rejected livers (%)
Affected lungs (%)
Period 1
5.16
(2.23 – 8.08)
340.80
(327.20 – 354.40)
Period 2
1.29
(-0.26 – 2.83)
361.43
(349.81 – 373.05)
Period 3
1.77
(0.94 – 2.60)
361.50
(349.97 – 373.03)
P-value
0.010*
5.24
(4.15 – 6.33)
714.77
(703.34 – 726.20)
2.53
(1.74 – 3.32)
723.43
(699.52 – 747.34)
3.19
(2.80 – 3.58)
731.67
(713.10 – 750.23)
0.001*
59.73
(59.18 – 60.28)
17.34
(17.01 – 17.67)
3.07
(2.85 – 3.29)
60.23
(59.36 – 61.10)
17.36
(16.87 – 17.85)
2.77
(2.53 – 3.00)
60.23
(59.28 – 61.19)
17.32
(17.10 – 17.54)
2.83
(2.71 – 2.94)
0.438
122.38
(119.46 – 125.29)
121.13
(117.12 – 125.14)
120.29
(117.55 – 123.03)
0.539
27.70
(24.44 – 30.96)
1.49
(0.95 – 2.04)
15.87
(12.32 – 19.42)
26.26
(20.72 – 31.79)
2.29
(1.18 – 3.39)
10.44
(5.62 – 15.27)
24.23
(18.08 – 30.39)
1.50
(0.46 – 2.54)
13.57
(11.06 – 16.08)
0.473
0.016
Table 3: mean (95% confidence interval) of the different parameters in the three study
periods and the corresponding P-value of the ANOVA-test.
* Result of the Kruskal-Wallis test, because Levene’s test was significant.
7
0.234
0.989
0.055
0.286
0.090
A post-hoc Bonferroni test indicated that the significant difference of average daily weight
gain (gram) of weaned piglets was between period 1 (Stellamune) and period 3
(FLEXcombo) (P 0.029). The difference between period 1 and period 2 was not significant (P
0.054). The median and spread of the average daily weight gain of weaned piglets is
depicted in Figure 1.
Figure 1: boxplot of the average daily weight gain (gram) of weaned piglets by vaccination
period.
Because of the small amount of data in period 2 (Table 2) and an outbreak of Actinobacillus
pleuropneumoniae in the fattening unit in autumn 2010 (starting July 2010) period 2 and
period 3 were combined and a two-sample t-test performed.
The results of the two-sample t-test with the mean and 95% confidence interval of the
different parameters are summarized in
Table 4.
8
Parameter
Mortality weaned piglets (%)
Average daily weight gain (gram) of
weaned piglets
Mortality fattening pigs (%)
Average daily weight gain (gram) of
fattening pigs
Muscle thickness (mm)
Fat thickness (mm)
Corrected energy conversion rate
fattening pigs
Days from entrance to finishing the
fattening unit
Pleuritis (%)
Rejected livers (%)
Affected lungs (%)
Period 1
5.16
(2.23 – 8.08)
340.80
(327.20 – 354.40)
5.24
(4.15 – 6.33)
714.77
(703.34 – 726.20)
59.73
(59.18 – 60.28)
17.34
(17.01 – 17.67)
3.07
(2.86 – 3.29)
122.38
(119.46 – 125.30)
27.70
(24.44 – 30.96)
1.84
(1.15 – 2.54)
15.87
(12.32 – 19.42)
Period 2 + 3
1.57
(0.87 – 2.27)
361.47
(354.10 – 368.84)
2.92
(2.53 – 3.30)
728.06
(715.05 – 741.07)
60.23
(59.65 – 60.81)
17.34
(17.13 – 17.55)
2.80
(2.70 – 2.91)
120.66
(118.63 – 122.68)
25.12
(201.37 – 28.87)
1.49
(0.95 – 2.04)
12.20
(9.87 – 14.53)
P-value
0.023
0.004
0.001
0.119
0.195
0.996
0.017
0.292
0.287
0.417
0.064
Table 4: mean (95% confidence interval) of the different parameters in the three study
periods and the corresponding P-value of the two-sample t-test.
In period 2 and 3 combined, the mortality of weaned piglets decreased and the average daily
weight gain improved. Similarly, mortality in fattening pigs decreased and the corrected
energy conversion rate improved (Table 4).
9
Discussion
On this farm vaccination with CircoFLEX improved the mortality of weaned piglets, average
daily weight gain of weaned piglets, mortality of fattening pigs and corrected energy
conversion rate of fattening pigs. There was no effect on the average daily weight gain of
fattening pigs, days from entrance to finishing the fattening unit and slaughterhouse
parameters.
In this study the vaccination periods ‘Stellamune® + CircoFLEX®’ and ‘CircoFLEX® +
MycoFLEX®’ were combined in the statistical analyses for biological reasons. Not only the
amount of data in the first mentioned period was small (Table 2), but there was also an
outbreak of Actinobacillus pleuropneumoniae in the fattening unit of the farm during these
two vaccination periods (July 2010 – November 2010), making them more similar.
Kim et al. (2011) described the efficacy of different vaccination schedules for M.
hyopneumoniae and PCV2 on humoral response, pathological observation and growth
performance from birth to finishing. A single dose schedule for M. hyopneumoniae at one
week of age and PCV2 at three weeks of age resulted in better growth performance (weight
and average daily weight gain) and less pathological lesions compared to a single dose
schedule at three weeks of age for both M. hyopneumoniae and PCV2. Baccaro et al. (2006)
described no effect of two different vaccines for M. hyopneumoniae, administered at
weaning, on growth performance, but only on pathological lesions.
In our study, Stellamune was given in the first week of life and Mycoflex in the third week of
life. By combining period 2 and period 3 it was not possible to measure the effect of
vaccination in the first week versus vaccination in the third week of life for M.
hyopneumoniae. However, we didn’t find an indication for an effect of vaccination moment,
since there were no significant differences between period 2 and period 3 in the ANOVA test
(Table 3). However, there was limited data available, especially in period 2, comparing the
effects of different commercial vaccines and vaccination moment against M. hyopneumoniae.
This could be an interesting topic for further research.
The results of this study correspond to earlier research of Kristensen et al. (2011), Martelli et
al. (2011) and Kixmöller et al. (2008). They found a significant increase of the average daily
weight gain and reduction of the mortality rate in finishing pigs and nursery-finishing pigs
after vaccination against PCV2. In our study we didn’t find a significant increase of the
average daily weight gain of finishing pigs. This could be due to an outbreak of Actinobacillus
pleuropneumoniae during the study periods of period 2 and 3. Another explanation could be
that the PCV2 infection was mainly concentrated in the nursery and less in the fattening unit.
The disadvantage of this study in three different vaccination cohorts is the time aspect.
Although we checked for confounding by season, there is a possibility for management
changes. The study period started in January 2009 and comprised around two years. It is
very likely that some management factors have changed over the years.
Since February 2011 there was a major change in the anticoccidial management of one
week old piglets, leading to less prevention and worsening of the results. Therefor
vaccination data till February 2011 were analysed.
10
Conclusion
Vaccination against PCV2 improved growth of weaned piglets and reduced mortality of
weaned piglets. The energy conversion rate of fattening pigs improved and the mortality of
fattening pigs decreased in this particular farm. The advantage of vaccination with
CircoFLEX® + MycoFLEX® in comparison with the Stellamune® + CircoFLEX® vaccination is
that the two vaccinations can be mixed and administered as a one shot vaccine. This is less
labour-intensive for the farmer, is less stressful for the animals and thus results in better
animal welfare.
11
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