TY - JOUR
T1 - Associations between lamb survival and prion protein genotype
T2 - Analysis of data for ten sheep breeds in Great Britain
AU - Gubbins, Simon
AU - Cook, Charlotte J.
AU - Hyder, Kieran
AU - Boulton, Kay
AU - Davis, Carol
AU - Thomas, Eurion
AU - Haresign, Will
AU - Bishop, Stephen C.
AU - Villanueva, Beatriz
AU - Eglin, Rachel D.
N1 - Funding Information:
This work was funded by the Department for Environment, Food and Rural Affairs (Defra) [grant code SE0236]. SG acknowledges additional funding from the Biotechnology and Biological Sciences Research Council (BBSRC) [grant code IAH1320] and BV acknowledges additional funding from the Scottish Government. The authors are particularly grateful to all the breeders who participated in the study. We also thank the National Sheep Association for helping to publicise the project; the National Scrapie Plan for Great Britain and Animal Health for blood sampling participating flocks; and Margaret Griffiths (NAWAD) and Bill Hill (University of Edinburgh) for helpful comments on the manuscript.
PY - 2009/1/21
Y1 - 2009/1/21
N2 - Background: Selective breeding programmes, based on prion protein (PrP) genotype, have been introduced throughout the European Union to reduce the risk of sheep transmissible spongiform encephalopathies (TSEs). These programmes could have negative consequences on other important traits, such as fitness and production traits, if the PrP gene has pleiotropic effects or is in linkage disequilibrium with genes affecting these traits. This paper presents the results of an investigation into associations between lamb survival and PrP genotype in ten mainstream sheep breeds in Great Britain (GB). In addition, the reasons for lamb deaths were examined in order to identify any associations between these and PrP genotype.Results: Survival times from birth to weaning were analysed for over 38000 lambs (2427 dead and 36096 live lambs) from 128 flocks using Cox proportional hazard models for each breed, including additive animal genetic effects. No significant associations between PrP genotype and lamb survival were identified, except in the Charollais breed for which there was a higher risk of mortality in lambs of the ARR/VRQ genotype compared with those of the ARR/ARR genotype. Significant effects of birth weight, litter size, sex, age of dam and year of birth on survival were also identified. For all breeds the reasons for death changed significantly with age; however, no significant associations between reason for death and PrP genotype were found for any of the breeds.Conclusion: This study found no evidence to suggest that a selective breeding programme based on PrP genotype will have a detrimental effect on lamb survival. The only significant effect of PrP genotype identified was likely to be of little consequence because an increased risk of mortality was associated with a genotype that is selected against in current breeding strategies.
AB - Background: Selective breeding programmes, based on prion protein (PrP) genotype, have been introduced throughout the European Union to reduce the risk of sheep transmissible spongiform encephalopathies (TSEs). These programmes could have negative consequences on other important traits, such as fitness and production traits, if the PrP gene has pleiotropic effects or is in linkage disequilibrium with genes affecting these traits. This paper presents the results of an investigation into associations between lamb survival and PrP genotype in ten mainstream sheep breeds in Great Britain (GB). In addition, the reasons for lamb deaths were examined in order to identify any associations between these and PrP genotype.Results: Survival times from birth to weaning were analysed for over 38000 lambs (2427 dead and 36096 live lambs) from 128 flocks using Cox proportional hazard models for each breed, including additive animal genetic effects. No significant associations between PrP genotype and lamb survival were identified, except in the Charollais breed for which there was a higher risk of mortality in lambs of the ARR/VRQ genotype compared with those of the ARR/ARR genotype. Significant effects of birth weight, litter size, sex, age of dam and year of birth on survival were also identified. For all breeds the reasons for death changed significantly with age; however, no significant associations between reason for death and PrP genotype were found for any of the breeds.Conclusion: This study found no evidence to suggest that a selective breeding programme based on PrP genotype will have a detrimental effect on lamb survival. The only significant effect of PrP genotype identified was likely to be of little consequence because an increased risk of mortality was associated with a genotype that is selected against in current breeding strategies.
UR - http://www.scopus.com/inward/record.url?scp=60549107771&partnerID=8YFLogxK
U2 - 10.1186/1746-6148-5-3
DO - 10.1186/1746-6148-5-3
M3 - Article
C2 - 19159456
AN - SCOPUS:60549107771
VL - 5
JO - BMC Veterinary Research
JF - BMC Veterinary Research
SN - 1746-6148
M1 - 3
ER -