title: The effect of paratuberculosis on milk yield--A systematic review and meta-analysis.
abstract: Bovine paratuberculosis is a disease characterized by chronic granulomatous enteritis causing protein-losing enteropathy. Adverse effects on animal productivity are key drivers in the attempt to control paratuberculosis at the farm level. Economic models require an accurate estimation of the production effects associated with paratuberculosis. The aim of this study was to conduct a systematic review and meta-analysis to investigate the effect of paratuberculosis on milk production. A total of 20 effect estimates from 15 studies were included in the final meta-analysis. Substantial between-study heterogeneity was observed. Subgroup analysis by case definition and study design was carried out to investigate heterogeneity. The majority of between-study variation was attributed to studies that defined cases on serology. Calculation of a pooled effect estimate was only appropriate for studies that defined cases by organism detection. A reduction in milk yield, corrected for lactation number and herd of origin of 1.87 kg/d, equivalent to 5.9% of yield, was associated with fecal culture or PCR positivity in individual cows.
authors.affiliation: Section of Herd Health and Animal Husbandry, School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland. Electronic address: mcaloonconor@gmail.com.
authors.forename: Conor G
authors.initials: CG
authors.lastname: McAloon
authors.affiliation: Section of Herd Health and Animal Husbandry, School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Paul
authors.initials: P
authors.lastname: Whyte
authors.affiliation: Section of Herd Health and Animal Husbandry, School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: More
authors.affiliation: School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, LE12 5RD, United Kingdom.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Green
authors.affiliation: Section of Herd Health and Animal Husbandry, School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Luke
authors.initials: L
authors.lastname: O'Grady
authors.affiliation: Animal and Grassland Research and Innovation Centre, Teagasc Moorepark, Fermoy, Co. Cork, Ireland.
authors.forename: AnaBelen
authors.initials: A
authors.lastname: Garcia
authors.affiliation: Section of Herd Health and Animal Husbandry, School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Doherty
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000191:economics / Q000382:microbiology / Q000503:physiopathology*; D005243:Feces / Q000382:microbiology; D005260:Female; D007774:Lactation; D008892:Milk / Q000378:metabolism* / Q000382:microbiology; D016927:Mycobacterium avium subsp. paratuberculosis / Q000235:genetics / Q000302:isolation & purification*; D010283:Paratuberculosis / Q000191:economics / Q000382:microbiology / Q000503:physiopathology*
keywords: Johne’s disease; meta-analysis; milk yield; paratuberculosis