Modelling of strategies for genetic control of scrapie in sheep: The importance of population structure

Thomas J. Hagenaars, Marielle B. Melchior, Jack J. Windig, Alex Bossers, Aart Davidse, Fred G. van Zijderveld

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Scrapie is a transmissible spongiform encephalopathy in sheep and an example of a disease that may be controlled through breeding for disease resistance. Member states of the European Union have introduced strategies for breeding against scrapie based on the selection of genetically resistant breeding rams. An ambitious strategy adopted in The Netherlands consisted of selecting resistant rams for breeding throughout both breeding and production sectors. Mathematical modelling of the effect of a breeding program on the spreading capacity of scrapie in a national flock is needed for making assessments on how long a breeding strategy needs to be maintained to achieve disease control. Here we describe such a model applied to the Dutch situation, with the use of data on the genetic content of the Dutch sheep population as well as on scrapie occurrence in this population. We show that the time needed for obtaining scrapie control depends crucially on two parameters measuring sheep population structure: the between-flock heterogeneity in genotype frequencies, and the heterogeneity of mixing (contact rates) between sheep flocks. Estimating the first parameter from Dutch genetic survey data and assuming scenario values for the second one, enables model prediction of the time needed to achieve scrapie control in The Netherlands.
LanguageEnglish
Article numbere0195009
JournalPLoS ONE
Volume13
Issue number3
DOIs
Publication statusPublished - 27 Mar 2018

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Scrapie
scrapie
genetic resistance
Breeding
Sheep
population structure
Disease control
sheep
breeding
Population
flocks
rams
Netherlands
Prion Diseases
Disease Resistance
prion diseases
European Union
disease resistance
disease control
mathematical models

Cite this

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title = "Modelling of strategies for genetic control of scrapie in sheep: The importance of population structure",
abstract = "Scrapie is a transmissible spongiform encephalopathy in sheep and an example of a disease that may be controlled through breeding for disease resistance. Member states of the European Union have introduced strategies for breeding against scrapie based on the selection of genetically resistant breeding rams. An ambitious strategy adopted in The Netherlands consisted of selecting resistant rams for breeding throughout both breeding and production sectors. Mathematical modelling of the effect of a breeding program on the spreading capacity of scrapie in a national flock is needed for making assessments on how long a breeding strategy needs to be maintained to achieve disease control. Here we describe such a model applied to the Dutch situation, with the use of data on the genetic content of the Dutch sheep population as well as on scrapie occurrence in this population. We show that the time needed for obtaining scrapie control depends crucially on two parameters measuring sheep population structure: the between-flock heterogeneity in genotype frequencies, and the heterogeneity of mixing (contact rates) between sheep flocks. Estimating the first parameter from Dutch genetic survey data and assuming scenario values for the second one, enables model prediction of the time needed to achieve scrapie control in The Netherlands.",
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Modelling of strategies for genetic control of scrapie in sheep : The importance of population structure. / Hagenaars, Thomas J.; Melchior, Marielle B.; Windig, Jack J.; Bossers, Alex; Davidse, Aart; van Zijderveld, Fred G.

In: PLoS ONE, Vol. 13, No. 3, e0195009, 27.03.2018.

Research output: Contribution to journalArticleAcademicpeer-review

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