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Epidemiological studies of reproductive performance indicators in Swedish dairy cows

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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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
Title:Epidemiological studies of reproductive performance indicators in Swedish dairy cows
Alternative abstract:
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :May 2012
Number of Pages:75
I.Löf, E., Gustafsson, H. & Emanuelson, U. (2007). Associations Between Herd Characteristics and Reproductive Efficiency in Dairy Herds. Journal of Dairy Science 90(10), 4897-4907.
II.Löf, E., Emanuelson, U. & Gustafsson, H. (2007). Data management affects reproductive performance indicators in Swedish dairy herds. Acta Agriculturae Scandinavica, Section A - Animal Science 57(2), 73-80.
III.Löf, E., Gustafsson, H. & Emanuelson, U. (2012). Evaluation of two dairy herd reproductive performance indicators that are adjusted for voluntary waiting period. Acta Veterinaria Scandinavica 54(1), 5.
IV.Löf E, Gustafsson H and Emanuelson U (2012). Factors influencing the chance of cows being pregnant 30 days after the voluntary waiting period. (in manuscript).
Place of Publication:Uppsala
Publisher:Institutionen för kliniska vetenskaper, Sveriges lantbruksuniversitet
ISBN for printed version:978-91-576-7664-1
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
Permanent URL:
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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