Abstract
Since the abolition of EU milk production quotas in 2015, Europe's dairy industries have undergone a period of rapid expansion with possible resultant increased inter-herd transmission of endemic pathogens. The aims of this study were (1) to establish the post-2015 prevalence of antibodies to selected endemic infectious diseases and (2) to determine if prevalences differed between herds where heifers were reared at home and those where heifers were sent out for contract-rearing. Three bulk tank milk (BTM) samples were collected annually between May and August of 2018–20 inclusively from 120 Irish dairy herds. Additionally, herd vaccination status was collected by questionnaire. Milk samples were tested using commercially available ELISAs for eight pathogens: bovine viral diarrhea virus (BVDV), bovine herpesvirus 1 (BoHv-1), bovine respiratory syncytial virus (BRSV), Mycoplasma bovis, Mycobacterium avium subspecies paratuberculosis (MAP), Salmonella Dublin (S. Dublin), Leptospira Hardjo (L. Hardjo), and Neospora caninum (N. caninum). The true prevalence of each pathogen was calculated using a Rogan-Gladen estimator. The true prevalences (95% CI) of BTM antibodies in unvaccinated herds across the 3 years were as follows (i) BVDV: 57, 86, and 73% (95% CI: 40.7–65.9, 74–94, and 58–85) (n = 56, 56, and 48), (ii) BoHv-1: 47, 49, and 19% (95% CI: 26.3–69.7, 25–75, and 1–56) (n = 21, 20, and 11), (iii) L. Hardjo: 34, 59, and 73% (95% CI: 12.5–63, 33–82, and 33–99) (n = 15, 21, and 10), (iv) S. Dublin 32, 57, and 11% (95% CI: 12.21–68.1, 30.2–90.1, and 0) (n = 19, 22, and 13), (v) BRSV: 100% (95% CI: 99.5–100, 100, and 100) (n = 120, 109, and 91), (vi) MAP: 0% (95% CI: 0, 0, and 0) (n = 120, 109, and 91) (vii) N. caninum 0% (95% CI: 0, 0, and 0) (n = 120, 109, and 91) and (viii) M. bovis (ELISA) 53, 0.42, and 30% (95% CI: 3.95–6.84, 0, and 21–41) (n = 120, 109, and 91). M. bovis was detected by PCR in 0, 1, and 0% of herds in 2018, 2019, and 2020, respectively. This study showed that expanding Irish dairy herds are endemically infected with several of the studied pathogens. No differences in herd prevalence of infectious agents were observed between farms with different heifer rearing strategies (contract-rearing vs. traditional rearing).
Highlights
This study showed that expanding Irish dairy herds are endemically infected with several of the studied pathogens
Several infectious diseases are endemic in the Irish cattle population including bovine viral diarrhea (BVD), Johne’s disease (MAP), infectious bovine rhinotracheitis (IBR), bovine respiratory syncytial virus (BRSV), tuberculosis, neosporosis, mycoplasmosis, salmonellosis and leptospirosis [1, 2]
Products available to vaccinate against BRSV in Ireland were marketed for the control of respiratory disease complex in calves, typically as multivalent vaccines
Summary
Several infectious diseases are endemic in the Irish cattle population including bovine viral diarrhea (BVD), Johne’s disease (MAP), infectious bovine rhinotracheitis (IBR), bovine respiratory syncytial virus (BRSV), tuberculosis, neosporosis, mycoplasmosis, salmonellosis and leptospirosis [1, 2]. The ELISA true prevalence of Johne’s disease among Irish dairy herds has previously been estimated 20.6% [7]. All of these studies were carried out prior to the abolition of EU milk quota in 2015. The aim of the quota system was to limit expansion of dairy production systems within member states. A US survey of dairy producers [9] found that all respondents engaged in herd expansion experienced increased losses associated with one or more of the following infectious diseases; BVD, Johne’s disease, and IBR as a result of breakdown in herd biosecurity practices [9]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
