A.A. Shadparvar

[ 1 ] - Accuracy of Genomic Prediction under Different Genetic Architectures and Estimation Methods

The accuracy of genomic breeding value prediction was investigated in various levels of reference population size, trait heritability and the number of quantitative trait locus (QTL). Five Bayesian methods, including Bayesian Ridge regression, BayesA, BayesB, BayesC and Bayesian LASSO, were used to estimate the marker effects for each of 27 scenarios resulted from combining three levels for her...

[ 2 ] - The Effect of Dams of Sire Path Management on Genetic and Economic Parameters in a Simulated Genomic Selection Program

A deterministic model based on the gene flow method, considering the features of Iranian Holstein cattle population, was implemented in this study to evaluate the effect of altering the number of age-classes in the dams of future sire (DS) path and the number of dams required for breeding a young bull (YB), to be evaluated as future sire, on genetic gain and resultant economic efficiency of a g...

[ 3 ] - Genetic Perspective of Ascites Syndrome in Meat-Type Chickens

Pulmonary hypertension syndrome (ascites) is a metabolic disorder in fast-growing broilers. Inconsistency of oxygen requirement and the cardiovascular ability make the birds susceptible to ascites. Incidence of ascites was accompanied by right ventricular hypertrophy, fluid accumulation in the abdominal cavity and finally mortality. The objective of the current study was to review the genetic b...

[ 4 ] - Estimation of Genetic Trends for Test-Day Milk Yield by the Logarithmic Form of Wood Function Using a Random Regression Model

Estimation of genetic trends is necessary to monitor and evaluate selection programs. The objective of this study was to estimate the genetic trends for milk yield in Iranian Holsteins cows using random regression test day model. Data set was consisted of 743205 test-day records from 1991 to 2008, which were collected by the Animal Breeding Centre of Iran. Breeding, environmental and phenotypic...

[ 5 ] - Genetic Trends for Milk Yield, Persistency of Milk Yield,Somatic Cell Count and Calving Interval in Holstein Dairy Cows of Iran

The objective of the present study was to estimate genetic trends for lactation milk yield, persistency of milk yield, somatic cell count and interval between first and second calving in Holstein dairy cows of Iran. The dataset consisted of 210,625 test day and 25,883 first parity cows with milk yield recorded from July 2002 to September 2007 comprising 97 herds in Iran. Breeding values of anim...

[ 6 ] - بررسی اثر ناسازگاری ماتریس های واریانس- کواریانس در شاخص انتخاب

In selection index procedure, phenotype and genetic (co)variance matrices of traits are used for calculating different genetic parameters like index coefficients, index variance, genetic gain in selection goal and selection accuracy. Sometimes, it is possible that these matrices become inconsistent or they are not positive, nor definite. In the current study, for investigation of the effect of ...

[ 7 ] - بررسی اثر ناسازگاری ماتریس های واریانس- کواریانس در شاخص انتخاب

In selection index procedure, phenotype and genetic (co)variance matrices of traits are used for calculating different genetic parameters like index coefficients, index variance, genetic gain in selection goal and selection accuracy. Sometimes, it is possible that these matrices become inconsistent or they are not positive, nor definite. In the current study, for investigation of the effect of ...

[ 8 ] - Simple and Constrained Selection Indices with and without Calving Interval Included in Selection Goal Function for Holstein Cows of Iran

Two selection goals of inclusion or exclusion of calving interval (CI) in the selection goal function for Holstein cows in Iran, besides milk yield, milk fat percentage, and milk protein percentage, were studied. Four selection indices were composed of using the information on production traits, CI and / or days from calving to first insemination (DFI). The results of the predicted genetic grow...

[ 9 ] - Effect of Markers Effect Estimation Methods, Population Structure and Trait Architercture on the Accuracy of Genomic Breeding Values

This study aimed to investigate the effect of the method of estimating the effects of markers , QTLs distribution, number of QTLs, effective population size and trait heritability on the accuracy of genomic predictions. Two effective population sizes, 100 and 500 individuals, were simulated by QMSim software. A 100 cM genome including one chromosome was simulated where 500 SNPs and two diffe...