Saman Abbasi; Mokhtar Ali Abbasi; Alireza Noshari
Volume 17, Issue 2 , October 2015, , Pages 391-401
Abstract
A total of 2000 records of egg quality of 746 birds and body weight data from 17th generation of Fars Native Fowl Breeding Station were used to estimate the genetic parameters of egg quality and body weight traits. Six univariate animal models with different random effects were fitted for each trait. ...
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A total of 2000 records of egg quality of 746 birds and body weight data from 17th generation of Fars Native Fowl Breeding Station were used to estimate the genetic parameters of egg quality and body weight traits. Six univariate animal models with different random effects were fitted for each trait. A model with direct additive genetic and maternal permanent environmental effects was the most appropriate model for mature weight. For body weight in 12th week, the model with direct additive genetic, maternal genetic and maternal permanent environmental effects was suitable. The model with direct additive genetic and maternal genetic effects was appropriate for albumen diameter, yolk weight and egg weight. For other traits, the simple animal model with direct animal additive genetic effect was the best model. Estimates of heritability were ranged from 0.02 (yolk weight) to 0.23 (albumen index) for internal egg quality and were ranged from 0.01 (egg weight) to 0.43 (egg shell strength) for external egg quality traits. These parameters were estimated 0.03, 0.07 and 0.18 for mature weight, body weights at 8th and 12th weeks, respectively. Genetic correlations between egg quality and body weight traits ranged from -0.79 to 0.80. In conclusion, selection based on the body weights at 8th and 12th weeks increases the egg weight, egg width and egg shape index. Selection for body weight in 12th week would increase the albumen weight and yolk diameters.
Mokhtar Ali Abbasi; Sima Savar Sofla
Volume 17, Issue 1 , April 2015, , Pages 1-8
Abstract
This study was evaluated some strategies and determined the suitable selection index for Afshari sheep using simulated data. The relative importance of traits was determined based on the estimated economic values and consequently, the most benefit traits were applied to selection indexes construction. ...
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This study was evaluated some strategies and determined the suitable selection index for Afshari sheep using simulated data. The relative importance of traits was determined based on the estimated economic values and consequently, the most benefit traits were applied to selection indexes construction. The interest indexes were different combination of traits including ewe body weight (EBW), annual wools weight (AWW) and total weaning weight for each exposed ewe (TWWEE). The index 1 was included all three mentioned traits. The indexes two, three and four were included (AWW, TWWEE), (EBW, TWWEE) and (TWWEE), respectively. The results indicated that the aggregate genotype, selection index and economic progress increased by increasing in the population size and decreasing in ram ratio, but made reduction in inbreeding average, in all indexes. In more cases, the aggregate genotype decreased by removing a trait in the index. The comparisons among indexes indicated that the most suitable selection index for this breed is index 1 which included EBW, AWW and TWWEE. This index had a maximum selection index average, aggregate genotype and economic progress.