Download Association of herd BHV-1 seroprevalence with respiratory

Association of herd BHV-1 seroprevalence
with respiratory disease in youngstock of
Estonian dairy cattle
K. Raaperia, S. Bougeardb, A. Aleksejeva, T. Orroa, A. Viltropa
aInstitute
of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences
of Epidemiology, Pig, Poultry and Fishes Laboratory, French Agency for Food,
Environmental, and Occupational Health Safety (Anses)
bDepartment
Introduction
Bovine respiratory disease (BRD) is usually of multifactorial origin, involving infectious, environmental and managementrelated factors as well as those related to stress and the immunity of the animal. Bovine herpesvirus 1 (BHV-1) is
considered to be an important component of the etiological complex causing BRD in cattle.
.
Aim of this study was to to investigate the associations of herd bovine herpesvirus 1 (BHV-1) status and respiratory
disease (BRD) occurrence in dairy calves and pre-breeding heifers. In addition, associations between farm management
related factors and the occurrence of BRD in that age group was evaluated.
Methods
Serum samples were collected from cows and youngstock from 103 dairy cattle herds and analyzed for antibodies
against BHV-1, bovine respiratory syncytial virus (BRSV), bovine virus diarrhea virus (BVDV), and Mycoplasma bovis (M.
bovis). Questionnaire was used to register herd management practices and disease occurrence.
Results
S y m m e tr ic v a ria b le p lo t
(a x e s F 1 a n d F 2 : 8 3 .7 7 % )
Table 1. Results of logistic regression analysis for risk factors for high
occurrence of respiratory disease in calves until three months old (99
herds)
Risk factor
Herds (n)
OR
p
RS V = 2
95% CI
h s iz e = 4
0 .7
BHV-1 prevalence in cows
0
1-49%
>50%
BVDV in heifers
0
1
Herd sizeb
20-99 cows
100-199 cows
200-399 cows
>400 cows
y o co =0
ve te m p =1
1
14.8
19.2
0.005
0.002
2.3; 95.5
3.0; 121.8
B V D= 0
F 2 (4 .4 5 %
38
26
35
IB R c o w =0
RSV =0
75
24
1
5.1
0.020
G EN C A L = 0
LA CCA L =0
in s e m p = 1
M b h e if =1
N A S CA L = 0
R ES C A L = 0
in s e m p =0
IB R h e if = 1
M b h e if = 0
R ES C A L = 1
h s iz e = 6
ve t e m p =0
G EN C A L = 1
in s o t h = 1
y o co =1
IB R c o w = 1
1.3; 20.1
IB R c o w = 2
r e g r o =1
IB R h e if = 0
h s iz e = 3
-0 .3
NA S C A L = 1
h s iz e = 5
L A CCA L= 1
RS V =1
B V D= 1
r e g r o =0
40
18
23
18
1
1.7
8.0
6.4
0.557
0.008
0.029
0.3; 9.3
1.7; 37.3
1.2; 33.8
Table 2. Results of logistic regression analysis for risk factors for high
occurrence of respiratory disease in heifers three to sixteen months old
(99 herds)
Risk factor
BVDV in heifers
0
1
Herd size
20-99
100-199
200-399
>400
in s o t h = 0
r e g r o =2
a
Herds (n)
OR
p
95% CI
76
23
1
4.3
0.027
1.2; 15.8
40
19
23
17
1
4.9
5.3
8.1
0.113
0.065
0.022
0.7; 34.4
0.9; 31.6
1.4; 49.1
-1 .3
-1 .5
- 0 .5
0 .5
1 .5
F 1 (7 9 .3 2 % )
Figure 1. Graphical display of Multiple Correspondence Analysis,
with respect to axis 1 and 2 for high occurrence of respiratory
disease symptoms in calves until three months old (99 herds)
Conclusions
•BHV-1 and BVDV were related to BRD in unweaned
calves
•BVDV is associated with BRD in older youngstock
•Higher occurrence of respiratory disease is generally
more likely in larger herds
•On-farm employees can participate in spreading of
the disease
•Holding youngstock separately from cows until
pregnancy and purchasing animals were factors
related to a higher risk for BRD
ACKNOWLEDGEMENTS
This research was supported financially by the Estonian Ministry
of Agriculture (Research contract 34-23 2006-2008) and
Estonian Ministry of Education (Research project 8-2/T9001).