Dairy cattle transition period : disease prevalence and risk factors in grazing and freestall systems
department or school: Land and Food Systems, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Darós, Rolnei Ruã
issued: 2019-07-25T15:35:31Z
issued: 2019
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Many dairy cows become ill in the weeks after calving. The goal of this thesis was to study the epidemiology of these ‘transition cow’ diseases in pasture and confinement systems by undertaking two large observational studies, one in Santa Catarina, Brazil and another in British Columbia, Canada. There is a dearth of research on the prevalence and incidence of transition period diseases in grazing systems. Using a cross sectional approach we measured the prevalence and risk factors for common transition period diseases in 53 small-scale, year-round, grazing dairy herds in Santa Catarina, Brazil. We found that the prevalence of metabolic and infectious diseases in these herds were comparable to those described on high producing indoor systems. Our findings also identified risk factors associated with transition period diseases in these grazing herds. One highly prevalent challenge in indoor systems is lameness, a malady that is often an overlooked in studies of transition period disease. Through a longitudinal study, we followed 455 dairy cows housed indoors on farms located in the lower Fraser Valley region of British Columbia, Canada, to: 1) measure lameness during the prepartum period and 2) assess how lameness contributes to the development of transition diseases. There was a high incidence of lameness during the non-lactating ‘dry’ period, and cows that were lame during the dry period were more likely to develop transition period diseases. One possible mechanism for this association is via reduced feeding time, as lame cows spent less time feeding than sound cows. Reduced body condition score during the dry period was also associated with increased risk of transition period diseases, independently of lameness and feeding time. I conclude that preventing lameness and body condition loss during the dry period may improve transition health.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/71099
note: DAIRY CATTLE TRANSITION PERIOD: DISEASE PREVALENCE AND RISK FACTORS IN GRAZING AND FREESTALL SYSTEMS by Rolnei Ruã Darós B.Sc., Universidade Federal de Santa Catarina, 2012 M.Sc., Universidade Federal de Santa Catarina, 2014 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Applied Animal Biology) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) July 2019 © Rolnei Ruã Darós, 2019 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: DAIRY CATTLE TRANSITION PERIOD: DISEASE PREVALENCE AND RISK FACTORS IN GRAZING AND FREESTALL SYSTEMS submitted by Rolnei Ruã Darós in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Applied Animal Biology Examining Committee: Marina A. G. von Keyserlingk Supervisor Daniel M. Weary Supervisory Committee Member Yvonne Lamers Supervisory Committee Member Ronaldo Cerri University Examiner Trevor Dummer University Examiner iii Abstract Many dairy cows become ill in the weeks after calving. The goal of this thesis was to study the epidemiology of these ‘transition cow’ diseases in pasture and confinement systems by undertaking two large observational studies, one in Santa Catarina, Brazil and another in British Columbia, Canada. There is a dearth of research on the prevalence and incidence of transition period diseases in grazing systems. Using a cross sectional approach we measured the prevalence and risk factors for common transition period diseases in 53 small-scale, year-round, grazing dairy herds in Santa Catarina, Brazil. We found that the prevalence of metabolic and infectious diseases in these herds were comparable to those described on high producing indoor systems. Our findings also identified risk factors associated with transition period diseases in these grazing herds. One highly preval…
has type: Thesis/Dissertation
date issued: 2019-09
is shown at: 10.14288/1.0380175
language: eng
degree discipline: Applied Animal Biology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/71099