Morteza Sattaei Mokhtari; Arsalan Barazandeh; Moslem Moghbeli damaneh; Zahra Roudbari
Abstract
In the present study, data collected from 1993 to 2011 in Raeini Cashmere goat breeding station were used for genetic evaluation and inferring causal relationships among reproductive traits applying structural equation models. The studied lifetime reproductive traits were included the overall number ...
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In the present study, data collected from 1993 to 2011 in Raeini Cashmere goat breeding station were used for genetic evaluation and inferring causal relationships among reproductive traits applying structural equation models. The studied lifetime reproductive traits were included the overall number of kids born (OLSB), the overall number of kids weaned (OLSW), the overall litter weight at birth (OLWB) and the overall litter weight at weaning (OLWW). Three models including standard (SMM), recursive based on prior knowledge (PRM) and recursive based on inductive causation algorithm (ICM) multivariate models were used for genetic evaluation of animals under the Bayesian approach. The comparisons of the investigated models via deviance information criterion (DIC), mean square error (MSE) and Pearson's correlations between observed and predicted records () revealed that ICM had lower DIC and MSE and higher () for all the studied lifetime reproductive traits; implying the more plausibility of ICM over SMM and PRM. Furthermore, re-raking of the animals under SMM and ICM confirmed the importance of considering the causal relationship among the traits for ensuring accurate ranking of animals according to their breeding values.
Fatemeh Mohammadinejad; Mohammadreza Mohammadabadi; Arsalan Barazandeh
Abstract
In this study, the records of survival of 3056 kids related to the breeding station of Raini Cashmere goat were used during years 1993-2004. These records were collected in Raein Breeding station located in the Baft city, Kerman province, Iran. The data were analyzed using linear and hazard ratio models ...
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In this study, the records of survival of 3056 kids related to the breeding station of Raini Cashmere goat were used during years 1993-2004. These records were collected in Raein Breeding station located in the Baft city, Kerman province, Iran. The data were analyzed using linear and hazard ratio models with Weibul function. These models included fixed factors such as year and month of birth, sex, type, age of dam and birth weight as quadratic covariate, and direct additive genetic, maternal additive genetic, maternal permanent environmental and residual random effects. Genetic parameters were estimated using restricted maximum likelihood procedure and different animal models contained with and without maternal and common environmental effects and sire model. The direct heritability of length of life and survival rate estimated from different linear models was low (0.01 to 0.06). The estimates of heritability in logarithmic scale, original scale and effective heritability obtained from sire and animal models with Weibull function were medium to high (0.17 to 0.70) and higher than analogous values estimated by different linear models. Medium estimates show that genetic and non-genetic factors affect survival. Hence, to improve these traits, selecting beside suitable management are necessary.