Use of SCC in genetic selection for reduced incidence of mastitis: A mixture model approach

J. Ødegård; P. Madsen; D. Gianola; G. Klemetsdal; J. Jensen; B. Heringstad; I.R. Korsgaard

Use of SCC in genetic selection for reduced incidence of mastitis: A mixture model approach

In: Mastitis in dairy production

Authors:

J. Ødegård

J. Ødegård ¹Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway

Search for other papers by J. Ødegård in
Current site
Google Scholar
PubMed

P. Madsen

P. Madsen ²Department of Animal Breeding and Genetics, Danish Institute of Agricultural Sciences, Research Centre Foulum, Tjele, Denmark

Search for other papers by P. Madsen in
Current site
Google Scholar
PubMed

D. Gianola

D. Gianola ³Department of Dairy Sciences, University of Wisconsin-Madison, Madison, USA
¹Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway

Search for other papers by D. Gianola in
Current site
Google Scholar
PubMed

G. Klemetsdal

G. Klemetsdal ¹Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway

Search for other papers by G. Klemetsdal in
Current site
Google Scholar
PubMed

J. Jensen

J. Jensen ²Department of Animal Breeding and Genetics, Danish Institute of Agricultural Sciences, Research Centre Foulum, Tjele, Denmark

Search for other papers by J. Jensen in
Current site
Google Scholar
PubMed

B. Heringstad

B. Heringstad ¹Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, Ås, Norway

Search for other papers by B. Heringstad in
Current site
Google Scholar
PubMed

, and

I.R. Korsgaard

I.R. Korsgaard ²Department of Animal Breeding and Genetics, Danish Institute of Agricultural Sciences, Research Centre Foulum, Tjele, Denmark

Search for other papers by I.R. Korsgaard in
Current site
Google Scholar
PubMed

Type:: Chapter

Pages:: 564–569

DOI:: https://doi.org/10.3920/9789086865505_085

Purchase instant access (PDF download and unlimited online access):

€42.00€35.00 excl. VAT

Add to Cart

Redeem Access Token

Mixture distributions consist of two or more sub-distributions (groups), where group memberships of the observations are unknown. The udder health status of each cow at the test-days on which SCC are recorded are usually unknown. Further, as SCC increases as a result of udder infection, the observed SCC/SCS can be assumed being a two (or more)- component mixture depending on mastitis status (e.g, healthy/mastitic). Using a mixture model for statistical analysis of observed test-day SCS implies that the observations can be categorized into putative disease categories according to the probability of disease, given the observed data and all other parameters in the model. A Bayesian hierarchical twocomponent normal mixture model for SCS was developed, where baseline SCS is associated with some fixed and random effects, and test-day health status is assumed fully determined by an underlying liability to mastitis. The prior probability of mastitis may vary between different sub-groups, such as herd, stage of lactation, lactation number, etc. Hence, the liability may be associated by some fixed and random effects distinct from those affecting baseline SCS. Based on analysis of simulated data, the model seemingly gives unbiased estimates of all parameters, and the predicted breeding values for liability to mastitis seem better suited for genetic selection than crudely selecting for lower SCS. The model also provides estimates of test-day probability of mastitis, based on the recorded SCS, which may be used for disease detection. The proposed model could easily be extended to handle a wider range of problems related to statistical analyses of mixture traits.

Citation Info

Save
Cite
Email this content

Share link with colleague or librarian

You can email a link to this page to a colleague or librarian:
Email this content
or copy the link directly:

https://brill.edhh.ma/abstract/book/9789086865505/BP000085.xml
The link was not copied. Your current browser may not support copying via this button.

Link copied successfully

Collapse
Expand

Mastitis in dairy production

Current knowledge and future solutions

E-Book ISBN:: 9789086865505

Publisher:: Wageningen Academic

Print Publication Date:: 24 Oct 2005

Subjects
- Life Sciences

Metrics

	All Time	Past 365 days	Past 30 Days
Abstract Views	95	33	12
Full Text Views	1	0	0
PDF Views & Downloads	0	0	0

African Studies	Education	Media Studies
American Studies	History	Middle East and Islamic Studies
Ancient Near East and Egypt	Human Rights and Humanitarian Law	Musicology
Art History	International Law	Philosophy
Asian Studies	International Relations	Religious Studies
Biblical Studies	Jewish Studies	Slavic and Eurasian Studies
Biology	Languages and Linguistics	Social Sciences
Book History and Cartography	Life Sciences	Theology and World Christianity
Classical Studies	Literature and Cultural Studies

Subjects

Authors

Open Access

Product Information

Company

Contact

Use of SCC in genetic selection for reduced incidence of mastitis: A mixture model approach

Citation Info

Share link with colleague or librarian

Mastitis in dairy production

Current knowledge and future solutions

Table of Contents

Metrics

Metrics