There were two farms that were free of all three pathogens (Farm 1 and Farm 3), while in the other 4 farms we found a positive result in at least one of the samples in a different age group (Table 1).
Table 1. Detection of pathogens (HEV, PCV2, PRRSV) in different age groups in oral fluid and faeces
|
Farm
number
|
5
weeks
old
|
7
weeks
old
|
9–10
weeks
old
|
11
weeks
old
|
12–13 weeks
old
|
Fatteners
|
Sows
|
HEV
|
6
|
pos
|
pos
|
pos
|
neg
|
neg
|
neg
|
neg
|
2
|
neg
|
neg
|
pos
|
neg
|
neg
|
neg
|
neg
|
PCV2
|
4
|
neg
|
neg
|
neg
|
pos
|
neg
|
neg
|
neg
|
6
|
pos
|
pos
|
pos
|
neg
|
neg
|
neg
|
neg
|
PRRSV
|
5
|
neg
|
pos
|
pos
|
pos
|
pos
|
pos
|
neg
|
pos = positive
neg = negative
The results of our study showed that the category (growers, fatteners and breeding sows) on farms 1 and 3, which were without PRRSV, PCV2 and HEV, significantly affected the values of the following parameters: WBC, Hb, MCH, MCHC, PLT, percentage of neutrophils, lymphocytes and eosinophils and the absolute numbers of neutrophils, lymphocytes, monocytes, basophils and LUCs (Tables 2, 3 and 4).
Furthermore, growers were divided into age categories: 5 weeks old growers (group label 5, N=18), 7 weeks old growers (group label 7, N=19), 9–10 weeks old growers (group label 9–10, N=19), 11 weeks old growers (group label 11, N=15) and 12–13 weeks old growers (group label 12–13, N=18). Every age category of growers was also compared to fatteners and sows. Cells corresponding to statistically different pairs of age groups are shown in the supplementary files (Additional files 1, 2 and 3).
On farms 1 and 3, significantly higher WBCs were observed in the growers than in the sows (Table 2). In addition, significantly lower Hb and MCHC levels and significantly higher PLT and lymphocyte count were observed in growers than in sows and fatteners (Tables 2 and 4). Significantly lower percentages of neutrophils and eosinophils and significantly higher percentage of lymphocytes and absolute numbers of neutrophils, monocytes, basophils and LUCs were found in growers than in sows (Tables 3 and 4).
Table 2: Complete blood count parameters (mean ± SD) of sows, growers (of all ages) and fatteners
|
PCR-negative farms
|
PCR-positive farms
|
|
|
|
|
growers (all ages) (N=89)
|
fatteners (N=9)
|
sows
(N=20)
|
growers (all ages) (N=181)
|
fatteners (N=39)
|
sows
(N=40)
|
p-value1
|
p-value2
|
p-value3 (G/F/S)
|
WBC [109/L]
|
22.2 ± 5.8
|
17.0 ± 3.2
|
12.4 ± 1.8
|
19.4 ± 7.8
|
20.8 ± 4.5
|
15.8 ± 4.1
|
<0.0001
|
<0.0001
|
ns/<0.01/<0.0001
|
RBC [1012/L]
|
6.25 ± 1.06
|
6.35 ± 1.12
|
5.86 ± 0.56
|
6.27 ± 0.81
|
6.96 ± 0.65
|
5.95 ± 0.75
|
ns
|
<0.0001
|
ns/ns/ns
|
Hb [g/L]
|
108 ± 17
|
122 ± 18
|
119 ± 10
|
109 ± 15
|
129 ± 10
|
123 ± 16
|
<0.01
|
<0.0001
|
ns/ns/ns
|
Hct [L/L]
|
0.376 ± 0.046
|
0.398 ± 0.071
|
0.367 ± 0.028
|
0.367 ± 0.057
|
0.408 ± 0.038
|
0.372 ± 0.048
|
ns
|
<0.0001
|
ns/ns/ns
|
MCV [fL]
|
60.1 ± 5.1
|
62.4 ± 3.2
|
63.1 ± 3.5
|
58.7 ± 4.4
|
59.1 ± 2.4
|
62.6 ± 3.4
|
ns
|
<0.0001
|
<0.05/<0.05/ns
|
MCH [pg]
|
17.4 ± 1.3
|
19.3 ± 1.2
|
20.4 ± 0.9
|
17.4 ± 1.4
|
18.6 ± 1.02
|
20.7 ± 0.95
|
<0.0001
|
<0.0001
|
ns/ns/ns
|
MCHC [g/L]
|
291 ± 17
|
309 ± 12
|
323 ± 13
|
296 ± 13
|
314 ± 10
|
323 ± 48
|
<0.0001
|
<0.0001
|
<0.05/ns/ns
|
PLT [109/L]
|
356 ± 133
|
192 ± 57
|
173 ± 106
|
406 ± 163
|
284 ± 102
|
214 ± 88
|
<0.0001
|
<0.0001
|
<0.01/<0.01/ns
|
ns = not significant
1significant differences between age categories on PCR-negative farms
2significant differences between age categories on PCR-positive farms
3significant differences between PCR-negative and PCR-positive farms in dependence on the pig category (G=growers; F=fatteners, S=sows)
On the other hand, on farms with PRRS, PCV2 and/or HEV, we found that age (i.e., breeding sows, different weeks old growers, fatteners) significantly affected the values of all observed blood parameters except the percentage of LUCs (Tables 2, 3 and 4). In sows, significantly lower WBC, RBC, absolute numbers of lymphocytes, basophils and significantly higher MCH were observed than in growers and fatteners (Tables 2 and 4). Significantly lower Hb, MCHC, percentages of neutrophils and eosinophils and significantly higher PLT, percentages of lymphocytes and neutrophils were observed in growers than in sows and fatteners (Tables 2 and 3). A significantly higher Hct was observed in fatteners than in growers and sows and a significantly lower percentage of basophils was observed in sows than in fatteners (Tables 2 and 3).
Table 3: White blood differential count parameters (relative values; mean ± SD) of sows, growers and fatteners
|
PCR-negative farms
|
PCR-positive farms
|
|
|
|
|
growers (all ages) (N=89)
|
fatteners (N=9)
|
sows
(N=20)
|
growers (all ages) (N=181)
|
fatteners (N=39)
|
sows
(N=40)
|
p-value1
|
p-value2
|
p-value3 (G/F/S)
|
Neut [%]
|
36.7 ± 10.5
|
40.5 ± 11.2
|
43.1 ± 9.0
|
45.1 ± 12.0
|
36.5 ± 7.6
|
47.2 ± 8.3
|
<0.001
|
<0.0001
|
<0.0001/<ns/<ns
|
Lymph [%]
|
54.0 ± 10.4
|
50.3 ± 11.9
|
46.1 ± 7.4
|
45.6 ± 11.7
|
52.0 ± 8.8
|
40.6 ± 7.5
|
<0.001
|
<0.0001
|
<0.0001/ns/<0.05
|
Mono [%]
|
5.26 ± 3.72
|
3.79 ± 1.02
|
3.96 ± 0.76
|
4.89 ± 2.27
|
4.43 ± 1.71
|
4.21 ± 1.04
|
ns
|
<0.001
|
ns/ns/ns
|
Eos [%]
|
2.93 ± 1.75
|
4.38 ± 1.75
|
6.01 ± 3.21
|
3.09 ± 1.77
|
6.01 ± 3.05
|
6.94 ± 3.74
|
<0.0001
|
<0.0001
|
ns/<0.05/ns
|
Baso [%]
|
0.303 ± 0.156
|
0.367 ± 0.200
|
0.280 ± 0.174
|
0.418 ± 0.255
|
0.497 ± 0.195
|
0.350 ± 0.138
|
ns
|
<0.0001
|
<0.0001/ns/ns
|
LUC [%]
|
0.817 ± 0.596
|
0.600 ± 0.472
|
0.625 ± 0.324
|
0.810 ± 0.694
|
0.623 ± 0.537
|
0.657 ± 0.340
|
<0.05
|
ns
|
ns/ns/ns
|
ns = not significant
1significant differences between age categories on PCR-negative farms
2significant differences between age categories on PCR-positive farms
3significant differences between PCR-negative and PCR-positive farms in dependence on the pig category (G=growers; F=fatteners, S=sows)
Sows on farms with PRRSV, PCV2 and/or HEV have significantly higher WBC, absolute numbers of neutrophils, monocytes, eosinophils and a significantly lower percentage of lymphocytes than on farms without any pathogen (Tables 2, 3 and 4). Growers on farms with PRRSV, PCV2 and/or HEV have significantly higher MCHC, PLT, percentage and absolute numbers of neutrophils and basophils but lower percentage and absolute number of lymphocytes (Tables 2, 3 and 4). Fatteners on farms with PRRSV, PCV2 and/or HEV have significantly higher WBC, PLT, percentage of eosinophils, absolute numbers of monocytes, eosinophils and basophils and lower MCV than on farms without any pathogen (Tables 2, 3 and 4).
Table 4: White blood differential count parameters (absolute values; mean ± SD) of sows, growers and fatteners
|
PCR-negative farms
|
PCR-positive farms
|
|
|
|
|
growers (all ages) (N=89)
|
fatteners
(N=9)
|
sows
(N=20)
|
growers (all ages) (N=181)
|
fatteners (N=39)
|
sows
(N=40)
|
p-value1
|
p-value2
|
p-value3 (G/F/S)
|
Neut [109/L]
|
8.35 ± 4.03
|
6.85 ± 2.18
|
5.40 ± 1.75
|
10.50 ± 4.99
|
7.55 ± 2.58
|
7.63 ± 3.19
|
<0.0001
|
<0.0001
|
<0.001/ns/<0.001
|
Lymph [109/L]
|
11.80 ± 3.21
|
8.59 ± 2.60
|
5.65 ± 1.04
|
10.20 ± 3.31
|
10.60 ± 2.45
|
6.22 ± 1.22
|
<0.0001
|
<0.0001
|
<0.001/ns/ns
|
Mono [109/L]
|
1.180 ± 0.787
|
0.658 ± 0.252
|
0.486 ± 0.098
|
1.150 ± 0.665
|
0.914 ± 0.414
|
0.661 ± 0.223
|
<0.001
|
<0.0001
|
ns/<0.05/<0.0001
|
Eos [109/L]
|
0.649 ± 0.512
|
0.769 ± 0.401
|
0.726 ± 0.337
|
0.687 ± 0.396
|
1.300 ± 0.932
|
1.110 ± 0.758
|
ns
|
<0.0001
|
ns/<0.05/<0.01
|
Baso
[109/L]
|
0.069 ± 0.039
|
0.061 ± 0.04
|
0.034 ± 0.019
|
0.098 ± 0.068
|
0.101 ± 0.040
|
0.057 ± 0.030
|
<0.001
|
<0.0001
|
<0.0001/<0.05/<0.001
|
LUC [109/L]
|
0.172 ± 0.120
|
0.102 ± 0.071
|
0.078 ± 0.045
|
0.187 ± 0.178
|
0.131 ± 0.117
|
0.108 ± 0.073
|
<0.0001
|
<0.01
|
ns/ns/ns
|
ns = not significant
1significant differences between age categories on PCR-negative farms
2significant differences between age categories on PCR-positive farms
3 significant differences between PCR-negative and PCR-positive farms in dependence on the pig category (G=growers; F=fatteners, S=sows)
In the presence of the considered pathogens, several differences between age groups emerged and were shown to be significant (Tables 2, 3 and 4). For instance, in the absence of all the considered pathogens, the differences between RBC and MCH values of different age groups (i.e., sows, growers, fatteners) were not significant, but they became significant for all age-group pairs (i.e., sows-growers, sows-fatteners, growers-fatteners) if any of the pathogens was present on the farm. In the absence of all the considered pathogens, the differences between Hct, MCV, percentage of basophils and absolute number of eosinophils of different age groups (i.e., sows, growers, fatteners) were not significant, but they became significant for at least one age-group pair (i.e., sows-growers, sows-fatteners or growers-fatteners) if any of the pathogens was present on the farm. In the absence of all the considered pathogens, there were significant differences between percentage of lymphocytes, eosinophils, absolute numbers of neutrophils and basophils of only sows and growers, but in the presence of the pathogens, at least one new age-group pair had significantly different parameter values. Parameter values for WBC, Hb, PLT, percentage and absolute numbers of monocytes, percentage and absolute numbers of LUCs are not significantly different for any of the age-group pairs if the pathogens are present on the farm. The presence of the pathogens eliminated the differences between different age groups in two haematological parameters: MCHC and absolute number of lymphocytes. Porcine Reproductive and Respiratory Virus significantly lowered percentage of lymphocytes, MCV and Hct, and increased WBC, PLT, percentage and absolute numbers of neutrophils, basophils and LUCs. Porcine Circovirus Type 2 significantly lowered percentage of lymphocytes and increased percentage and absolute numbers of neutrophils, eosinophils and basophils. Hepatitis E Virus significantly lowered MCV and percentage of lymphocytes and increased RBC, Hb, percentage and absolute number of basophils and percentage of neutrophils.