In a production model that simulates farm outputs, depending on farm type, farrowing rhythm or length of suckling period, an epidemiological model was integrated. In this, the impact of PRRS infection on health and productivity was estimated. Financial losses were calculated in a gross margin analysis and a partial budget analysis based on the changes in health and production parameters assumed for different PRRS disease severities. Data on the effects of endemic infection on reproductive performance, morbidity and mortality, daily weight gain, feed efficiency and treatment costs were obtained from literature and expert opinion. Nine different disease scenarios were calculated, in which a farrow-to-finish farm (1000 sows) was slightly, moderately or severely affected by PRRS, based on changes in health and production parameters, and either in breeding, in nursery and fattening or in all three stages together.
Annual losses ranged from a median of € 75'724 (90% confidence interval (C.I.): € 78'885-€ 122'946), if the farm was slightly affected in nursery and fattening, to a median of € 650'090 (90% C.I. € 603'585-€ 698'379), if the farm was severely affected in all stages. Overall losses were slightly higher if breeding was affected than if nursery and fattening were affected. In a herd moderately affected in all stages, median losses in breeding were € 46'021 and € 422'387 in fattening, whereas costs were € 25'435 lower in nursery, compared with a PRRSV-negative farm.
The model is a valuable decision-support tool for farmers and veterinarians if a farm is proven to be affected by PRRS (confirmed by laboratory diagnosis). The output can help to understand the need for interventions in case of significant impact on the profitability of their enterprise. The model can support veterinarians in their communication to farmers in cases where costly disease control measures are justified.
Nathues H, Alarcon P, Rushton J, Jolie R, Fiebig K, Jimenez M, Geurts V, Nathues C; Cost of Porcine Reproductive and Respiratory Syndrome Virus at Individual Farm Level - An Economic Disease Model; Prev Vet Med. 2017 Jul 1;142:16-29. doi: 10.1016/j.prevetmed.2017.04.006. Epub 2017 Apr 27. PMID: 28606362 DOI: 10.1016/j.prevetmed.2017.04.006