Estimated production and economic losses from Neospora caninum infection in Texas beef herds

Abstract

A computerized spreadsheet was used to model economic losses attributed to changes in production parameters for a typical 42 head Texas beef herd following a simulated N. caninum infection. Texas beef herds that completed Standardized Performance Analysis (SPA) records between 1991-1997 supplied the representative production information for economic analysis. SPA production parameters that were used included pregnancy percentage, calving percentage (live calves born), calf death loss between birth and weaning (%), weaned calf crop (%), pounds of calf weaned per female exposed to bulls at start of breeding season, and replacement percentage. The prevalence of N. caninum across and within herds, the risk of increased abortions and stillbirths in infected cows, and the percentage of aborting cows that were culled were collectively superimposed onto the production information in the model either as static estimates (deterministic model) or changing estimates (stochastic model) to cause change in production parameters. Using a deterministic approach and compared to a non-infected herd, a herd with a 20% prevalence of infection experienced an estimated 2.4% lower calving percentage and an overall estimated 2.3% lower weaned calf crop. Estimated weaned calf weight per exposed female was 12.3 lb (5.6 kg) less in an infected herd. Predicted economic loss was $13.75 per head ($577.50 herd loss). Using software that facilitated stochastic modelling, average predicted loss was between $23.29 per head ($978.18 herd loss) and $35.21 per head ($1478.82 herd loss). The total predicted economic loss to the Texas beef industry from this disease was estimated to be $7.6 million using the deterministic economic model. When prevalence figures were allowed to vary, the most likely financial losses to the Texas beef industry were predicted to be between $15 million and $24 million.