scholarly journals Linear and Threshold Model Comparisons for Genotypic and Phenotypic Parameters Estimation on Reproductive Traits in Zandi Sheep

2016 ◽  
Vol 7 (14) ◽  
pp. 172-165
Author(s):  
Masomeh Ataollah ◽  
Hossein Moradi Shahrbabk ◽  
Morteza Sattaei Mokhtari
Keyword(s):  
Threshold Model ◽  
Reproductive Traits ◽  
Parameters Estimation ◽  
Model Comparisons ◽  
Zandi Sheep

scholarly journals Variance Component and Breeding Value Estimation for Reproductive Traits in Laying Hens Using a Bayesian Threshold Model

2007 ◽  
Vol 86 (5) ◽  
pp. 823-828 ◽  
Author(s):  
J. Bennewitz ◽  
O. Morgades ◽  
R. Preisinger ◽  
G. Thaller ◽  
E. Kalm
Keyword(s):  
Variance Component ◽  
Laying Hens ◽  
Threshold Model ◽  
Reproductive Traits ◽  
Breeding Value ◽  
Value Estimation

scholarly journals Threshold models for the determination of genetic variability among reproductive traits in Nellore cattle

2020 ◽  
Vol 55 ◽  
Author(s):  
Leonardo Martin Nieto ◽  
Luiz Otávio Campos da Silva ◽  
Antônio do Nascimento Ferreira Rosa
Keyword(s):  
Genetic Variability ◽  
Threshold Model ◽  
Reproductive Traits ◽  
Threshold Models ◽  
Multiple Trait ◽  
Bayesian Procedures ◽  
Nellore Cattle ◽  
Heritability Estimates ◽  
Maternal Grandsire

Abstract: The objective of this work was to evaluate the potential of different threshold models to determine the genetic variability in Nellore cattle, with basis on the heritability estimates for the traits stayability (STA) and first calving probability at 36 months of age (CP36). Data came from the Nellore herds participating in the animal breeding program of the Embrapa-Geneplus partnership. Binomial and multi-threshold models were defined for the STA and CP36 traits. Heritability estimates were obtained following Bayesian procedures in the Multiple-trait Gibbs Sampler for Animal Models (MTGSAM) software, using a sire-maternal grandsire model. The heritability estimates, provided by the binary and alternative models, were, respectively, 0.08 and 0.12 for STA and 0.17 and 0.12 for CP36. The multi-threshold model can efficiently detect the genetic variability for stayability, but not for probability of calving for 36-month-old cows.

Genetic correlations between growth and reproductive traits in Zandi sheep

2014 ◽  
Vol 46 (5) ◽  
pp. 895-899
Author(s):  
Kourosh Mohammadi ◽  
Mohammad Taghi Beigi Nassiri ◽  
Enayat Rahmatnejad ◽  
Rostam Abdollahi-Arpanahi ◽  
Seyed Mohammad Reza Hossaini ◽  
...  
Keyword(s):  
Genetic Correlations ◽  
Reproductive Traits ◽  
Zandi Sheep

scholarly journals An algorithm for genetic variance estimation of reproductive traits under a threshold model

2003 ◽  
Vol 46 (1) ◽  
pp. 85-91
Author(s):  
K. Molinski ◽  
M. Szydlowski ◽  
T. Szwaczkowski ◽  
A. Dobek ◽  
E. Skotarczak
Keyword(s):  
Fixed Effects ◽  
Genetic Variance ◽  
Variance Estimation ◽  
Threshold Model ◽  
Simulated Data ◽  
Reproductive Traits ◽  
Unknown Parameters ◽  
Additive Variance ◽  
Mixing Properties ◽  
Fertility Data

Abstract. Some binary traits are determined by a large number of loci. The standard approach, in this case, is to model an unobservable variable (liability) with a fixed threshold. We present a method for the estimation of the genetic additive variance component under a threshold animal model with fixed effects included. The method can be applied to data with repeated measurement per animal. The unknown parameters of the model have been estimated by Gibbs sampling. The numerical properties of the method are investigated on simulated data for a large real pedigree of breeding stock of laying hens. The algorithm shows good mixing properties, producing consistent estimates from many distinct runs. The application of the method is exemplified on fertility data recorded for the same pedigree.

Phenotypic and genetic parameter estimates for reproductive traits in Zandi sheep

2012 ◽  
Vol 45 (2) ◽  
pp. 671-677 ◽  
Author(s):  
Kourosh Mohammadi ◽  
Mohammad Taghi Beigi Nassiri ◽  
Enayat Rahmatnejad ◽  
Masoud Sheikh ◽  
Jamal Fayazi ◽  
...  
Keyword(s):  
Genetic Parameter ◽  
Reproductive Traits ◽  
Parameter Estimates ◽  
Zandi Sheep

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

2012 ◽  
Vol 57 (No. 8) ◽  
pp. 382-388 ◽  
Author(s):  
H. Mohammadi ◽  
M. Moradi Shahrbabk ◽  
M. Vatankhah
Keyword(s):  
Environmental Effects ◽  
Fixed Effects ◽  
Strong Influence ◽  
Genetic Parameters ◽  
Reproductive Traits ◽  
Linear Analysis ◽  
Threshold Analysis ◽  
Selection Indexes ◽  
Estimation Of Genetic Parameters ◽  
Zandi Sheep

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.  

scholarly journals Heritability of reproduetive traits in Asturiana de los Valles beef cattle breed

2001 ◽  
Vol 44 (5) ◽  
pp. 489-496 ◽  
Author(s):  
F. Goyache ◽  
J. P. Gutierrez
Keyword(s):  
Growth Traits ◽  
Threshold Model ◽  
Random Effect ◽  
Cattle Breed ◽  
Reproductive Traits ◽  
Gestation Length ◽  
Calving Interval ◽  
Improvement Program ◽  
Age At First Calving ◽  
Calving Ease

Abstract. Heritability was estimated for four reproductive traits in the Asturiana de los Valles breed in order to evaluate the possibility of include this information in the breed's current improvement program. The estimations were done using an animal model except for calving ease score. For this last trait, a threshold model under a sire model was fitted, with the sire effect as the only random effect in the model besides the residual. Estimated heritabilities for calving interval age at first calving, gestation length, as dam traits, and calving ease were 0.12, 0.27, 0.15 and 0.42, respectively. The estimated heritability for calving interval and age at first calving could justify a sire selection program in the Asturiana de los Valles breed taking account their female offsprings' reproductive characteristics. Heritability estimates for gestation length and calving ease suggested a close genetic relationship of these two traits and birth weight. Further research is needed to estimate the genetic (co)variances between these three traits to allow the use of this information in a breed improvement program to reduce dystocia without affecting preweaning growth traits.

A Hierarchy of Multinomial Models for Multidimensional Source Monitoring

Methodology ◽  
2005 ◽  
Vol 1 (1) ◽  
pp. 2-17 ◽  
Author(s):  
Thorsten Meiser
Keyword(s):  
Cognitive Processes ◽  
Source Monitoring ◽  
Source Information ◽  
Model Comparisons ◽  
Storage And Retrieval ◽  
Multinomial Processing Tree ◽  
Multinomial Models ◽  
Hierarchical Relationship ◽  
Statistical Framework ◽  
Tree Models

Abstract. Several models have been proposed for the measurement of cognitive processes in source monitoring. They are specified within the statistical framework of multinomial processing tree models and differ in their assumptions on the storage and retrieval of multidimensional source information. In the present article, a hierarchical relationship is demonstrated between multinomial models for crossed source information ( Meiser & Bröder, 2002 ), for partial source memory ( Dodson, Holland, & Shimamura, 1998 ) and for several sources ( Batchelder, Hu, & Riefer, 1994 ). The hierarchical relationship allows model comparisons and facilitates the specification of identifiability conditions. Conditions for global identifiability are discussed, and model comparisons are illustrated by reanalyses and by a new experiment on the storage and retrieval of multidimensional source information.

Planting time and mulching influenced vegetative and reproductive traits in strawberry (Fragaria×ananassaDuch.) in India

Fruits ◽  
2005 ◽  
Vol 60 (6) ◽  
pp. 395-403 ◽  
Author(s):  
Rajbir Singh ◽  
Ram Roshan Sharma ◽  
Rajiv Kumar Jain
Keyword(s):  
Reproductive Traits ◽  
Planting Time
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