Bayesian Estimates of Genetic Relationships between Growth Curve Parameters in Shall Sheep via Gibbs Sampling
محورهای موضوعی : Camel
1 - Department of Animal Science, Faculty of Agricultural Science, University of Guilan, Rasht, Iran
کلید واژه: genetic parameter, bayesian methodology, fat-tailed sheep, Gibbs sampling, growth curve,
چکیده مقاله :
The objective of this study was to estimate variance components and genetic parameters for growth curve parameters in Shall sheep. Studied traits were parameters of Brody growth model which included A (asymptotic mature weight), B (initial animal weight) and K (maturation rate). The data set and pedigree information used in this study were obtained from the Animal Breeding Center of Iran and comprised 4020 growth curve parameters of lambs from birth to 400 days of age during 1982 to 2012. Marginal posterior distributions of parameters and variance components were estimated using TM program. The Gibbs sampler was run 300000 rounds and the first 60000 rounds were discarded as a burn-in period. Posterior mean estimates of direct heritabilities for A, B and K were 0.13, 0.15 and 0.19, respectively. Estimates of direct genetic correlation between growth curve parameters were 0.41, -0.30 and -0.31 between A-B, A-K and B-K, respectively. Residual correlations between growth curve parameters varied from -0.57 (between A-K) to 0.62 (between A-B). Also, phenotypic correlations between growth curve parameters varied from -0.48 (between B-K) to 0.30 (between A-B). The low estimates of heritability obtained in this study implies that although genetic selection could be partially affected on the growth curve parameters, much of the improvement in these parameters could be attained by improvement of production environment rather than genetic selection in this breed of sheep.
Abegaz S., Van Wyk J.B. and Olivier J.J. (2010). Estimation of genetic and phenotypic parameters of growth curve and their relationship with early growth and productivity in Horro sheep. Arch. Tierz. 53(1), 85-94.
Amou Posht-e- Masari H., Shadparvar A.A., Ghavi Hossein-Zadeh N. and Hadi Tavatori M.H. (2013). Estimation of genetic parameters for reproductive traits in shall sheep. Trop. Anim. Health Prod. 45, 1259-1263.
Bathaei S.S. and Leroy P.L. (1998). Genetic and phenotypic aspects of the growth curve characteristics in Mehraban Iranian fat-tailed sheep. Small Rumin. Res. 29, 261-269.
Bedier N.Z., Younis A.A., Galal E.S.E. and Mokhta M.M. (1992). Optimum ewe size in desert Barki sheep. Small Rumin. Res. 7, 1-7.
Brody S. (1945). Bioenergetics and Growth. Rheinhold Publishing, New York, USA.
Gbangboche A.B., Glele-Kakai R., Salifou S., Albuquerque L.G. and Leroy P.L. (2008). Comparison of non-linear growth models to describe the growth curve in west African dwarf sheep. Animal. 2, 1003-1012.
Ghavi Hossein-Zadeh N. (2011). Genetic parameters and trends for calving interval in the first three lactations of Iranian Holsteins. Trop. Anim. Health Prod. 43, 1111-1115.
Ghavi Hossein-Zadeh N. and Ardalan M. (2010). Estimation of genetic parameters for body weight traits and litter size of Moghani sheep, using a Bayesian approach via Gibbs sampling. J. Agric. Sci. 148, 363-370.
Hyndman R.J. (1996). Computing and graphing highest density regions. Am. Stat. 50, 120-126.
KachmanS.D. and Gianola D. (1984). A Bayesian estimator of variance and covariance components in nonlinear growth models. J. Anim. Sci. 59(1), 176.
Legarra A., Varona L. and Lopez de Maturana E. (2011). TM Threshold Model. Available at:
Magnabosco C.U., Lôbo R.B. and Famula T.R. (2000). Bayesian influence for genetic parameter estimation on growth traits for Nellore cattle in Brazil, using the Gibbs sample. J. Anim. Breed. Genet. 117, 169-188.
Malhado C.H.M., Carneiroa P.L.S., Affonso P.R.A.M., Souza Jr A.A.O. and Sarmento J.L.R. (2009). Growth curves in Dorper sheep crossed with the local Brazilian breeds, Morada Nova, Rabo Largo and Santa Inês. Small Rumin. Res. 84, 16-21.
Maniatis N. and Pollott G.E. (2003). The impact of data structure on genetic (co)variance components of early growth in sheep, estimated using an animal model with maternal effects. J. Anim. Sci. 81, 101-108.
Mavrogenis A.P. and Constantinou A. (1990). Relationships between pre-weaning growth, post-weaning growth and mature body size in Chios sheep. Anim. Prod. 50(2), 271-275.
Näsholm A. (1990). Mature weight of ewe as a trait in sheep breeding. Pp. 88-91 in Proc. 4th World Cong. Genet. Appl. Livest. Prod., Edinburgh, UK.
SAS Institute. (2002). SAS®/STAT Software, Release 9.1. SAS Institute, Inc., Cary, NC. USA.
Schaeffer L.R. (1984). Sire and cow evaluation under multiple trait models. J. Dairy Sci. 67, 1567-1573.
Smith B.J. (2005). Bayesian Output Analysis Program (BOA), Version 1.1.5. The University of Iowa.
http://www.public-health.uiowa.edu/boa. Accessed Nov. 04, 2014.
Souza L.A., Carneiro P.L.S., Malhado C.H.M., Silva F.F. and Silveira F.G. (2013). Traditional and alternative nonlinear models for estimating the growth of Morada Nova sheep. Revist. Bras. Zootec. 42(9), 651-655.
Stobart R.H. (1983). Genetic and phenotypic analysis of liveweight maturing patterns and their relationship to ewe productivity in Colombia, Rambouillet and Targhee sheep. Dissert. Abs. Int. Part B: Sci. Engin. 44(6), 1656.
Stobart R.H., Bassett J.W., Cartwright T.C. and Blackwell R.L. (1986). An analysis of body weights and maturing patterns in western range ewes. J. Anim. Sci. 63, 729-740.
Tosh J.J. and Kemp R.A. (1994). Estimation of variance components for lamb weights in three sheep populations. J. Anim. Sci. 72, 1184-1190.
Van der Westhuizen R.R., Schoeman S.J., Jordaan G.F. and Van Wyk J.B. (2001). Genetic parameters for reproductive traits in a beef cattle herd estimated using multitrait analysis. South African J. Anim. Sci. 31, 41-48.
