Babak Enayati
Abstract
The aim of this study was to design optimal selection index without the use of economic coefficients based on the expected genetic gains in economic traits. Random simulation with 5 replications was used to evaluate the results of the designed indices. Simulated traits include body weight at birth (BW1), ...
Read More
The aim of this study was to design optimal selection index without the use of economic coefficients based on the expected genetic gains in economic traits. Random simulation with 5 replications was used to evaluate the results of the designed indices. Simulated traits include body weight at birth (BW1), eight weeks (BW8), twelve weeks (BW12), maturation (BWM), age at first laying (AFE), weight of first egg (EWM), the mean egg weight from 28 to 32 weeks (EW) and the egg number (EN). In three indices, BW12, EN and EW traits were in the selection target and all simulated traits were in the selection criterion. Indices with the aim of genetic gain for 5 g in EW, 20 in EN and the difference between the three indices of the first to third selection were related to the change in the expected values of 100, 200 and 300 gr in BW12. The results showed that all three selection indicators are able to create a uniform and desirable genetic gain in traits. However, the second index is able to achieve acceptable results in a smaller number of generations (304 gr, 25.3 and 6.4 gr genetic gain for BW12, EN and EW, respectively). The inbreeding after 5 generations of the implementation of the first to third indices was not desirable (approximately 0.02) and the difference in inbreeding between the indices was not significant (P> 0.4). It is suggested that the second index for 5 generations be used for the Yazd province native fowls breeding.
Babak Enayati
Abstract
The purpose of this study was to compare the four mating strategies in ostrich flocks using simulation. Simulated traits included egg production (EggsPro), chicken production (ChicksPro), hatchability (Hatchability), live weight at the beginning of mating (LWB), and live weight at the end of mating (LWE). ...
Read More
The purpose of this study was to compare the four mating strategies in ostrich flocks using simulation. Simulated traits included egg production (EggsPro), chicken production (ChicksPro), hatchability (Hatchability), live weight at the beginning of mating (LWB), and live weight at the end of mating (LWE). The selection of males was based on the breeding value of the LWB trait and the selection of females based on the breeding value of the ChicksPro trait. The first strategy was an optimal mating, the second strategy crossed individuals based on the highest genetic gain, regardless of the increase in inbreeding, the third strategy was the mating of individuals based on the lowest inbreeding, regardless of genetic progress, and the fourth strategy was the mating of individuals randomly, regardless of inbreeding and genetic gain. The results showed that if the goal in a breeding program is rapid progress without limitation on inbreeding, a mating strategy with the highest genetic gain is the best suited, and if there is no possibility of mapping this crosses, a random mating can be replaced. In closed populations with high inbreeding or populations that need to be genetically protected, and secondly important the breeder also wants to improve performance in the economic traits, a mating strategy with minimum inbreeding can be desirable, and if the goal of breeding is a continuous, sustained and significantly improvement in economic traits, which is required to prevent inbreeding, the optimal mating strategy could be the best option.
meysam latifi; Mohammad Almasi; Babak Enayati
Abstract
This study was conducted for genetic analysis of Markhoz goats for autosomal and X chromosomes for average daily gain traits from birth to yearling. The data set contained 3837 average daily gain from birth to weaning (ADG1), 3467 average daily gain from weaning to 6-month (ADG2), 3133 average daily ...
Read More
This study was conducted for genetic analysis of Markhoz goats for autosomal and X chromosomes for average daily gain traits from birth to yearling. The data set contained 3837 average daily gain from birth to weaning (ADG1), 3467 average daily gain from weaning to 6-month (ADG2), 3133 average daily gain from 6-month to 9-month (ADG3) and 2726 average daily gain from 9-month to 12-month (ADG4) collected during 1992-2014 in Markhoz Goat Breeding Center of Sanandaj. Fixed effects affecting the studied traits were determined using Proc GLM of the SAS 8.2 software and variance components and genetic parameters were estimated by Average Information algorithm of Restricted Maximum Likelihood (AI-REML) using Wombat software. The most appropriate model for each trait was determined by Akaike’s Information Criterion (AIC) test. Direct autosomal heritability estimates for ADG1, ADG2, ADG3 and ADG4 were 0.14±0.03, 0.00±0.02, 0.14±0.04 and 0.06±0.03, respectively. X-linked direct heritability estimates for these traits were negligible values of 0.00±0.02, 0.08±0.02, 0.06±0.02 and 0.04±0.02, respectively. Maternal heritability for ADG1 and ADG3 were 0.06±0.02 and 0.04±0.03, respectively. Maternal permanent environmental variance for ADG3 and ADG4 were 0.03±0.02. The low estimations of direct heritabilities for autosomal and sexual chromosomes were obtained in the current study, therefore direct selection for these traits would be generate a relatively slow genetic progress.
