Czech J. Anim. Sci., 2012, 57(8):382-388 | DOI: 10.17221/6274-CJAS

Estimation of genetic parameters of reproductive traits in Zandi sheep using linear and threshold models

H. Mohammadi1, M. Moradi Shahrebabak1, H. Moradi Sharebabak1, M. Vatankhah2
1 Department of Animal Science, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
2 Department of Animal Science, Agriculture and Natural Resources Research Centre, Shahrekord, Iran

Genetic parameters for reproductive traits in Zandi sheep were estimated from data records of 5025 lambs from 178 sires and 1967 dams collected between the years 1993 and 2010 using ASReml statistical package. Genetic parameters were estimated for four basic and two composite traits. Year of lambing and age of ewe were used as fixed effects. Due to repeated record of ewe animal direct genetic effects and permanent environmental effects were considered random. The heritability estimates for conception rate, number of lambs born, number of lambs born alive, number of lambs alive at weaning, number of lambs born per ewe exposed, and number of lambs weaned per ewe exposed were low with linear model - 0.05, 0.14, 0.12, 0.09, 0.05, and 0.04 respectively while the estimates resulting from threshold analysis were 0.11, 0.19, 0.14, 0.16, 0.12, and 0.11, respectively. Estimates of heritabilities for animal genetic and permanent environmental effects were low mainly due to the typical strong influence of environmental factors on reproductive traits. Estimates of repeatabilities for animal permanent environmental effects were low to medium by linear analysis, and medium by threshold analysis. These estimates of genetic parameters may provide a basis for deriving selection indexes for reproductive traits.

Keywords: reproductive traits; genetic parameters; linear model; threshold model; Zandi sheep

Published: August 31, 2012  Show citation

ACS AIP APA ASA Harvard Chicago Chicago Notes IEEE ISO690 MLA NLM Turabian Vancouver
Mohammadi H, Moradi Shahrebabak M, Moradi Sharebabak H, Vatankhah M. Estimation of genetic parameters of reproductive traits in Zandi sheep using linear and threshold models. Czech J. Anim. Sci. 2012;57(8):382-388. doi: 10.17221/6274-CJAS.
Share...
Download citation
  • BibTeX (.bib)
  • Bookends (.ris)
  • EasyBib (.ris)
  • EndNote (.enw)
  • EndNote 8 (.xml)
  • ISI WoS (.isi)
  • Medlars (.medlars)
  • Mendeley (.ris)
  • MODS (.xml)
  • Papers (.ris)
  • RefWorks (.txt)
  • RefManager (.ris)
  • RIS (.ris)
  • MS Word (.xml)
  • Zotero (.ris)
    • Open full article

    References

    1. Abdel-Azim G.A., Berger P.J. (1999): Properties of threshold model predictions. Journal of Animal Science, 77, 582-590. Go to original source...
    2. Afolayan R.A., Fogarty N.M., Gilmour A.R., Ingham V.M., Gaunt G.M., Cummins L.J. (2008): Reproductive performance and genetic parameters in first cross ewes from different maternal genotypes. Journal of Animal Science, 86, 804-814. Go to original source... Go to PubMed...
    3. Berger J. (1994): Genetic predictions for calving ease in the United States: data, models, and use by the dairy industry. Journal of Dairy Science, 77, 1146-1153. Go to original source... Go to PubMed...
    4. Brien F.D., Konstantinov K.V., Greeff J.C. (2002): Comparison of linear and threshold models for predicting direct and maternal genetic effects on number of lambs weaned in western Australian Merino sheep. In: Proc. 7th World Congr. Genetics Applied to Livestock Production (WCGALP), Montpellier, France, 307-310.
    5. Casellas J., Caja G., Ferret A., Piedrafita J. (2007): Analysis of litter size and days to lambing in the Ripollesa ewe. II. Estimation of variance components and response to phenotypic selection on litter size. Journal of Animal Science, 85, 625-631. Go to original source... Go to PubMed...
    6. Ceyhan A., Sezenler T., Erdogan S. (2009): The estimation of variance components for prolificacy and growth traits of Sakiz sheep. Livestock Science, 122, 68-72. Go to original source...
    7. Ekiz B., Ozcan M., Yilmaz A., Ceyhan A. (2005): Estimates of phenotypic and genetic parameters for ewe productivity traits of Turkish Merino (Karacabey Merino) sheep. Turkish Journal of Veterinary Animal Science, 29, 557-564.
    8. Fogarty N.M. (1995): Genetic parameters for live weight, fat and muscle measurements, wool production and reproduction in sheep: a review. Animal Breeding Abstracts, 63, 101-143.
    9. Gianola D., Foulley J.L. (1983): Sire evaluation for ordered categorical data with a threshold model. Genetics Selection Evolution, 15, 201-224. Go to original source... Go to PubMed...
    10. Gilmour A.R., Anderson R.D., Rae A.C. (1985): The analysis of binomial data by generalized linear mixed model. Biometrika, 72, 593-599. Go to original source...
    11. Gilmour A.R., Gogel B.J., Cullis B.R., Thompson R. (2006): ASReml User Guide, Release 2.0. VSN International Ltd., Hemel Hempstead, UK.
    12. Hanford B.K.J., van Vleck L.D., Snowder G.D. (2006): Estimates of genetic parameters and genetic trend for reproduction, weight, and wool characteristics of Polypay sheep. Livestock Science, 102, 72-82. Go to original source...
    13. Harville D.A., Mee R.W. (1984): A mixed-model procedure for analyzing ordered categorical data. Biometrics, 40, 393-408. Go to original source...
    14. Janssens S., Vandepitte W., Bodin L. (2004): Genetic parameters for litter size in sheep: natural versus hormone-induced oestrus. Genetics Selection Evolution, 36, 543-562. Go to original source... Go to PubMed...
    15. Matika O., van Wyk J.B., Erasmus G.J., Baker R.L. (2003): Genetic parameter estimates in Sabi sheep. Livestock Production Science, 79, 17-28. Go to original source...
    16. Matos C.A.P. (1993): Genetic analysis of reproductive discrete traits in sheep using linear and nonlinear models. PhD Diss. Madison, USA: Univ. of WisconsinMadison.
    17. Matos C.A.P., Thomas D.L., Gianola D., Pérez-Enciso M., Young L.D. (1997): Genetic analysis of discrete reproductive traits in sheep using linear and nonlinear models. II. Goodness of fit and predictive ability. Journal of Animal Science, 75, 88-94. Go to original source... Go to PubMed...
    18. Maxa J., Norberg E., Berg P., Pederson J. (2007): Genetic parameters for growth traits and litter size in Danish Texel, Shropshire, Oxford Down, and Suffolk. Small Ruminant Research, 68, 312-317. Go to original source...
    19. Mekkawy W., Roehe R., Lewis R.M., Davies M.H., Bunger L., Simm G., Haresign W. (2010): Comparison of repeatability and multiple trait threshold models for litter size in sheep using observed and simulated data in Bayesian analyses. Journal of Animal and Breeding Genetics, 127, 261-271. Go to original source... Go to PubMed...
    20. Mokhtari M.S., Rashidi A., Esmailizadeh A.K. (2010): Estimates of phenotypic and genetic parameters for reproductive traits in Kermani sheep. Small Ruminant Research, 88, 27-31. Go to original source...
    21. Poortahmasb A., Vatankhah M., Mirzaei H.R. (2007): Study of performance and estimation of genetic parameters of reproductive traits in Lori-Bakhtiari sheep of Sholi station using linear and threshold models. Pajouhesh & Sazandegi, 20, 126-131.
    22. Quaas R.L., Zhao Y., Pollak E.J. (1988): Describing interactions in dystocia scores with a threshold model. Journal of Animal Science, 66, 396-399. Go to original source... Go to PubMed...
    23. Rao S. (1997): Genetic analysis of sheep discrete reproductive traits using simulation and field data. PhD Diss. Blacksburgh, USA: Virginia Polytechnic Institute and State University.
    24. Rao S., Notter, D.R. (2000): Genetic analysis of litter size in Targhee, Suffolk, and Polypay sheep. Journal of Animal Science, 78, 2113-2120. Go to original source... Go to PubMed...
    25. Rashidi A., Mokhtari M.S., Esmailizadeh A.K., Asadi Fozi M. (2011): Genetic analysis of ewe productivity traits in Moghani sheep. Small Ruminant Research, 96, 11-15. Go to original source...
    26. Rosati A., Mousa E., Van Vleck L.D., Young L.D. (2002): Genetic parameters of reproductive traits in sheep. Small Ruminant Research, 43, 65-74. Go to original source...
    27. Safari E., Fogarty N.M., Gilmour A.R. (2005): A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep. Livestock Production Science, 92, 271-289. Go to original source...
    28. SAS Institute Inc. (2004): SAS Propriety Software Release 9.1 of the SAS ® System for Microsoft ® Windows®. SAS Institute Inc., Cary, USA.
    29. Schaeffer L.R. (2004): Applications of linear models in animal breeding. University of Guelph, Canada, 121- 132.
    30. van Wyk J.B., Fair M.D., Cloete S.W.P. (2003): Revised models and genetic parameter estimates for production and reproduction traits in the Elsenburg Dormer sheep stud. South African Journal of Animal Science, 33, 213-222. Go to original source...
    31. Vanimisetti H.B., Notter D.R., Kuehn L.A. (2007): Genetic (co)variance components for ewe productivity traits in Katahdin sheep. Journal of Animal Science, 85, 60-68. Go to original source... Go to PubMed...
    32. Vatankhah M., Talebi M.A., Edriss M.A. (2008): Estimation of genetic parameters for reproductive traits in Lori-Bakhtiari sheep. Small Ruminant Research, 74, 216-220. Go to original source...

    This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY NC 4.0), which permits non-comercial use, distribution, and reproduction in any medium, provided the original publication is properly cited. No use, distribution or reproduction is permitted which does not comply with these terms.


    Return to the content