Document Type: Original Article

Authors

1 M.Sc. Genetic and Animal Breeding, University of Zanjan, Iran

2 Assistant Department of Animal Sciences, University of Zanjan, Iran

Abstract

In this research genetic and phenotypic parameters were estimated using linear and threshold models, for reproductive traits, data from 6 large industrial dairy herd of East Azerbaijan province collected by Agriculture Jihad Organization during 10 years (2001-2010). Best linear unbiased predictions of traits breeding values were estimated using Restricted Maximum Likelihood method by WOMBAT software. Marginal posterior distributions under Bayesian approach via Gibbs sampling algorithm were estimated using repeatability analysis under animal model by Thrgibbs1f90software, in threshold model. Heritability’s of inseminations to conception and success at first insemination traits were estimated 0.078±0.014 and 0.068±0.013 respectively, in linear model and in threshold model, the means of posterior distributions of heritability’s  were estimated 0.07±0.0001 and 0.136±0.0022 respectively. The research results showed that although the amount of heritability’s for reproductive traits are low using linear and threshold models, but using threshold model in contrast with linear model cause increasing accuracy of evaluation and increasing rate of response to selection.  

Keywords

Carlen E, Emanuelson U, Strandberg E, 2006. Genetic evaluation of mastitis in dairy cattle using linear models, threshold models, and survival analysis, A simulation study, J Dairy Sci 89:4049–4057.
GhaviHossein-Zadeh N, 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 AgriSci 148: 363-370.
Gianola D, Foulley J L, 1983. Sire evaluation for ordered categorical data with a threshold model, Genet SelEvol 15:201–224.
Hagger C, Hofer A, 1990. Genetic analyses of calving traits in the Swiss Black and White،Braunvieh and Simmental Breeds by REML and MAPP procedures, Livest Prod Sci 24:93–107.
Javed K, Abdullah M, Akhtar M, Afzal M, 2004. Phenotypic and genetic correlations between first lactation milk yield and some performance traits in Sahiwal cattle, Pakistan Vet J 2: 9-12.
Kaps M, Lamberson W R, 2004. Biostatistics for animal science, CABI publishing, UK. Maxa J, Norberg E, Berg P, Milerski M, 2007. Genetic parameters for body weight, longissimus muscle depth and fat depth for Suffolk sheep in the Czech Republic, Small Rumin Res Pp: 87-91.
Meijering A, Gianola D, 1985. Linear versus nonlinear metods of sire evolutions for categorical traits: a simulation study, Genetics Selection Evolution 17: 115-132.
Mc Daniel B T, Bell W E, 1989. Genetic gain in milk yield from three systems of sire selection, J Dairy Sci 72: 68.
Misztal I, Tsuruta S, Strabel T, Auvray B, Druet T, Lee D H, 2002. BLUPF90 and related programs (BGF90), Proc, 7th World Congress on Genetic Applied to Livestock Production, Montpellier, France. Communication No. 28–07.
Olynk N J, Wolf C A, 2008. Economic analysis of reproductive management strategies on UScommercial dairy farms, J Dairy Sci 91:4082–4091.
Ramirez-Valverde R, Misztal I, Bertrand J K, 2001. Comparison of threshold vs linear and animal vs sire models for predicting direct and maternal genetic effects on calving difficulty in beef cattle, J AnimSci 79: 333–338.
SAS Institute Inc, 2004. SAS Propriety Software Release 9.1 of the SAS® System for Microsoft® Windows®, SAS Institute Inc, Cary, USA.
Schaeffer L R, 2004. Applications of linear models in animal breeding, University of Guelph, Canada.
Silvestre A M, Ginja M M D, Ferreira A G A, Colaco J, 2007. Comparison of estimates of hip dysplasia genetic parameters in Estrela Mountain Dog using linear and threshold models, J AnimSci 85:1880–1884.
Tekerli M, Gundogan M, 2005. Effect of certain factors in productive and reproductive efficiency traits and phenotypic relationships among these traits and repeatabilities in West Anatokian Holsteins, Turc, J Vet Amin Sci 29: 17-22.
Varona L, Misztal I, Bertrand J K, 1999. Threshold-linear versus linear-linear analysis of birth weight and calving ease using an animal model, I, Comparison of models, J AnimSci 77: 2003-2007.
Weigal K, Rekaya A, 2000. Genetic parameters for reproductive traits of Holstein cattle in California and Minnesota, J Dairy Sci 83: 1072-1080.
Weller J I, Ezra E, 2004. Genetic analysis of the Israeli Holstein dairy cattle population for production and nonproduction traits with a multitrait animal model, J Dairy Sci 87: 1519-1527.