Associations between Johne’s disease and fertility in UK dairy herds

Reynolds, J. A.; Bradley, A. J.; Sherwin, V. E.; Remnant, J. G.; Hudson, C. D.

Abstract

The objective of this observational study was to quantify associations between Mycobacterium avium subspecies paratuberculosis (MAP) antibody status and a variety of fertility outcomes, in UK dairy cattle. Longitudinal milk recording, fertility and MAP antibody enzyme-linked immunosorbent assay (ELISA) milk test data were collated retrospectively from 121,762 lactations in 78 herds. Datasets were structured into appropriate units to suit outcomes and enable temporal association between current and future MAP status, and fertility measures. Current MAP status was categorised according to most recent status within 180 days, with time-related future MAP status assigned based on MAP antibody ELISA milk test data for each cow. Multilevel multivariable logistic regression models were used to evaluate associations between MAP status and 21-day pregnancy and submission rate and conception risk. Posterior predictions and cross-validation techniques were used to assess model fit and check model building assumptions. A negative association was found between risk of insemination (Odds Ratio [OR], 0.78; 95% Credible Interval [CI], 0.66–0.92) and conception occurring (OR, 0.65; CI, 0.5–0.84) and transition from negative to non-negative MAP test status in the next 30–90 days. A positive association was observed between risk of insemination (OR, 1.34; CI, 1.16–1.52) and conception occurring (OR, 1.26; CI, 1.11–1.43) and transition from negative to non-negative MAP test status in the next 90–180 days. Current positive MAP test status was negatively and positively associated with insemination (OR, 0.59; CI, 0.49–0.70) and conception risk (OR, 1.12; CI, 0.96–1.30), respectively. Herd managers will have had access to test results, declaring cows with past recent or multiple positive MAP antibody ELISA results not to be bred, negatively influencing insemination risk. Overall, these results demonstrate the temporal association between a positive MAP antibody ELISA result and dairy cow fertility outcomes, with particular variability prior to a positive MAP antibody ELISA result.

Citation

Reynolds, J. A., Bradley, A. J., Sherwin, V. E., Remnant, J. G., & Hudson, C. D. (2023). Associations between Johne’s disease and fertility in UK dairy herds. Veterinary Journal, 298-299, Article 106015. https://doi.org/10.1016/j.tvjl.2023.106015

• Journal Article Type: Article
• Acceptance Date: Jul 18, 2023
• Online Publication Date: Jul 20, 2023
• Publication Date: 2023-08
• Deposit Date: Jul 25, 2023
• Publicly Available Date: Jul 26, 2023
• Journal: Veterinary Journal
• Print ISSN: 1090-0233
• Electronic ISSN: 1532-2971
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 298-299
• Article Number: 106015
• DOI: https://doi.org/10.1016/j.tvjl.2023.106015
• Keywords: Dairy cows; Fertility performance; Johne’s disease; Paratuberculosis
• Public URL: https://nottingham-repository.worktribe.com/output/23475000
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S1090023323000667
• Additional Information: This article is maintained by: Elsevier; Article Title: Associations between Johne’s disease and fertility in UK dairy herds; Journal Title: The Veterinary Journal; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.tvjl.2023.106015; Content Type: article; Copyright: © 2023 The Authors. Published by Elsevier Ltd.