Löf, Emma
(2012).
Epidemiological studies of reproductive performance indicators in Swedish dairy cows.
Diss. (sammanfattning/summary)
Uppsala :
Sveriges lantbruksuniv.,
Acta Universitatis Agriculturae Sueciae, 1652-6880
; 2012:28
ISBN 978-91-576-7664-1
[Doctoral thesis]
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820kB |
Abstract
Reproductive efficiency in dairy cows is a key factor for milk producers, and numerous studies have identified impaired reproductive performance as a major cause of reduced production efficiency in the dairy industry. The overall aim of this thesis was to gain knowledge of factors affecting the reproductive performance indicators currently used by herd advisory services and to find other, possibly more efficient, ways to measure reproductive performance in dairy cows.
The studies included in this thesis were based mainly on records from the Cattle Database at the Swedish Dairy Association, but also on data from a simulation model. The records used in the constituent studies of the thesis came from 2728 herds (Paper I), 483 herds (Paper II), 900 simulated herds (Paper III), and 132,721 individual cows (Paper IV). The statistical analyses were performed using multivariable linear and logistic regression models as well as survival analysis.
Many statistically significant associations were found between herd and cow characteristics and reproductive performance. When allocating advisory service resources to improve reproductive performance, the focus should be on easily influenced herd characteristics, such as heat detection efficiency, nutritional status, do-it-yourself inseminations, and health deviations. Herd characteristics were also found to influence the degree of disagreements in reproductive performance indicators when data were updated after six months. Reproductive performance indicators that were adjusted for management strategy were evaluated, and percentage pregnant after the herd voluntary waiting period plus 30 days was found to be the best reproductive performance indicator with which to assess both reproductive management and reproductive physiology. Both percentage pregnant after the herd voluntary waiting period plus 30 days and percentage inseminated after the herd voluntary waiting period plus 30 days could be integrated for use in the herd advisory services. These indicators would be useful in providing information on herd performance and in establishing more efficient benchmarking between herds.
Authors/Creators: | Löf, Emma | ||||||||||
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Title: | Epidemiological studies of reproductive performance indicators in Swedish dairy cows | ||||||||||
Alternative abstract: |
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Series/Journal: | Acta Universitatis Agriculturae Sueciae (1652-6880) | ||||||||||
Year of publishing : | May 2012 | ||||||||||
Number: | 2012:28 | ||||||||||
Number of Pages: | 75 | ||||||||||
Papers/manuscripts: |
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Place of Publication: | Uppsala | ||||||||||
Publisher: | Institutionen för kliniska vetenskaper, Sveriges lantbruksuniversitet | ||||||||||
ISBN for printed version: | 978-91-576-7664-1 | ||||||||||
ISSN: | 1652-6880 | ||||||||||
Language: | English | ||||||||||
Publication Type: | Doctoral thesis | ||||||||||
Full Text Status: | Public | ||||||||||
Agris subject categories.: | L Animal production > L53 Animal physiology - Reproduction L Animal production > L72 Pests of animals | ||||||||||
Subjects: | Obsolete subject words > VETERINARY MEDICINE > Veterinary epidemiology | ||||||||||
Agrovoc terms: | dairy cows, herds, reproductive performance, reproduction, reproduction control, epidemiology, sweden | ||||||||||
Keywords: | dairy, herd characteristics, reproductive performance indicators, voluntary waiting period, dairy cows, epidemiology, reproductive efficiency | ||||||||||
URN:NBN: | urn:nbn:se:slu:epsilon-e-473 | ||||||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-473 | ||||||||||
ID Code: | 8802 | ||||||||||
Department: | (VH) > Dept. of Clinical Sciences | ||||||||||
External funders: | Stiftelsen Lantbruksforskning | ||||||||||
Deposited By: | Emma Löf | ||||||||||
Deposited On: | 07 May 2012 10:53 | ||||||||||
Metadata Last Modified: | 02 Dec 2014 10:50 |
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