Type

Journal Article

Authors

Simon John More
Guy McGrath
P O'Sullivan
David A. Graham
Tracy A Clegg

Subjects

Veterinary

Topics
bovine virus diarrhea mucosal disease diarrhea viruses bovine viral female animals cattle prevention control animal virology epidemiology models theoretical temporal factors retention male first years bovine viral diarrhoea virus calves disease eradication ireland physiology risk factors survival model infection risk

Temporal trends in the retention of BVD+ calves and associated animal and herd-level risk factors during the compulsory eradication programme in Ireland (2016)

Abstract The national BVD eradication programme in Ireland started on a voluntary basis in 2012, becoming compulsory in 2013. The programme relies on accurate identification and prompt removal of BVD+ calves. However, a minority of herd owners have chosen to retain BVD+ animals (defined as still being alive more than seven weeks after the date of the initial test), typically with a view to fattening them to obtain some salvage value. During each year of the programme, additional measures have been introduced and implemented to encourage prompt removal of BVD+ animals. The objective of this study was to describe temporal trends in the retention of BVD+ calves and associated animal and herd-level risk factors during the first three years of the compulsory eradication programme in Ireland. The study population included all BVD+ calves born in Ireland in 2013–2015. A parametric survival model was developed to model the time from the initial BVD test until the animal was slaughtered/died on farm or until 31 December 2015 (whichever was earlier). A total of 29,504 BVD+ animals, from 13,917 herds, were included in the study. The proportion of BVD+ animals that were removed from the herd within 7 weeks of the initial test date increased from 43.7% in 2013 to 70.3% in 2015. BVD+ animals born in 2015 had a much lower survival time (median = 33 days) compared to the 2013 birth cohort (median = 62 days), with a year on year reduction in survival of BVD+ calves. In the initial parametric survival models, all interactions with herd type were significant. Therefore, separate models were developed for beef and dairy herds. Overall the results of the survival models were similar, with birth year, BVD+ status, herd size, county of birth and birth month consistently identified as risk factors independent of herd type (beef or dairy) or the numbers of BVD+ animals (single or multiple) in the herd. In addition, the presence of a registered mobile telephone number was identified as a risk factor in all models except for dairy herds with a single BVD+, while the sex of the BVD+ calf was only identified as a risk factor in this model. Significant progress has been made in addressing the issue of retention of BVD+ calves, however, there is a need for further improvement. A number of risk factors associated with retention have been identified suggesting areas where future efforts can be addressed.
Collections Ireland -> University College Dublin -> Veterinary Medicine Research Collection
Ireland -> University College Dublin -> CVERA Research Collection

Full list of authors on original publication

Simon John More, Guy McGrath, P O'Sullivan, David A. Graham, Tracy A Clegg

Experts in our system

1
S J More
University College Dublin
Total Publications: 171
 
2
Guy McGrath
University College Dublin
Total Publications: 46
 
3
P O'Sullivan
University College Dublin
Total Publications: 6
 
4
David A. Graham
University College Dublin
Total Publications: 22
 
5
T A Clegg
University College Dublin
Total Publications: 46