title: An investigation of the efficacy of a polyvalent mastitis vaccine using different vaccination regimens under field conditions in the United Kingdom.
abstract: Vaccination can play a useful role in mastitis control programs, although there is a relative dearth of large, well-controlled field efficacy studies. This paper presents the findings on the use of a commercially available vaccine (Startvac, Hipra UK Ltd., Nottingham, UK) on commercial units under UK field conditions. In total, 3,130 cows were recruited from 7 farms and were randomly allocated, within farm, to 1 of 3 groups. The first group received the vaccine following the label regimen, the second group was vaccinated every 90 d following an initial vaccination course, and the third group was left unvaccinated to act as controls. Vaccine efficacy was assessed in the first 120 d of lactation. Data were available for analysis from 1,696 lactations in 1,549 cows. In total, 779 cases of clinical mastitis occurred in the 3 study groups, and we detected no significant difference in the incidence or prevalence of clinical or subclinical mastitis between any of the 3 groups. Mastitis vaccination following the label regimen was associated with a significant reduction in the severity of clinical cases. Cows in this group were at significantly decreased odds of developing clinical mastitis presenting with more than just milk changes [odds ratio: 0.58; 95% confidence interval (CI): 0.35-0.98]. Similarly, each additional vaccination resulted in a cow being at decreased odds of developing clinical mastitis presenting with more than just milk changes (odds ratio: 0.87; 95% CI: 0.77-0.98). Although no cows were culled because of severe mastitis in either of the vaccinated groups, we detected no significant difference in the mastitis-related culling rate between groups. Analysis of milk production data demonstrated that, on average, cows on the label regimen produced a higher volume of milk (231 L; 95% CI: 104.1-357.4) and more milk solids (12.36 kg; 95% CI: 3.12-21.60) than unvaccinated cows in the first 120 d of lactation. Conservative analysis suggested that a return on investment of 2.57:1 could be expected under UK conditions based on increased milk yield alone.
authors.affiliation: Quality Milk Management Services Ltd., Cedar Barn, Easton Hill, Easton, Nr Wells, Somerset, BA5 1DU, United Kingdom; University of Nottingham, School of Veterinary Medicine and Science, Sutton Bonington Campus, Sutton Bonington, Leicestershire, LE12 5RD, United Kingdom. Electronic address: Andrew.Bradley@qmms.co.uk.
authors.forename: A J
authors.initials: AJ
authors.lastname: Bradley
authors.affiliation: Quality Milk Management Services Ltd., Cedar Barn, Easton Hill, Easton, Nr Wells, Somerset, BA5 1DU, United Kingdom; University of Nottingham, School of Veterinary Medicine and Science, Sutton Bonington Campus, Sutton Bonington, Leicestershire, LE12 5RD, United Kingdom.
authors.forename: J E
authors.initials: JE
authors.lastname: Breen
authors.affiliation: Quality Milk Management Services Ltd., Cedar Barn, Easton Hill, Easton, Nr Wells, Somerset, BA5 1DU, United Kingdom.
authors.forename: B
authors.initials: B
authors.lastname: Payne
authors.affiliation: Quality Milk Management Services Ltd., Cedar Barn, Easton Hill, Easton, Nr Wells, Somerset, BA5 1DU, United Kingdom.
authors.forename: V
authors.initials: V
authors.lastname: White
authors.affiliation: University of Nottingham, School of Veterinary Medicine and Science, Sutton Bonington Campus, Sutton Bonington, Leicestershire, LE12 5RD, United Kingdom.
authors.forename: M J
authors.initials: MJ
authors.lastname: Green
mesh_terms: D000818:Animals; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D002417:Cattle; D004926:Escherichia coli / Q000276:immunology*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D005260:Female; D008414:Mastitis, Bovine / Q000382:microbiology / Q000517:prevention & control*; D013203:Staphylococcal Infections / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000276:immunology*; D013997:Time Factors; D006113:United Kingdom; D014611:Vaccination / Q000662:veterinary*; D015164:Vaccines, Inactivated / Q000008:administration & dosage
chemical_list: D001428:Bacterial Vaccines; D015164:Vaccines, Inactivated
keywords: Escherichia coli; coliform; mastitis; milk production; vaccination