Mojdeh Mahmoudi Zarandi; Mohammad Rokouei; Mehdi Vafaei Valleh; Ali Maghsoudi
Volume 22, Issue 1 , Winter 2020, , Pages 9-22
Abstract
This study was done in order to estimate genetic parameters of growth and feed efficiency traits in Japanese quail. The data set consisted of 7762 records for feed efficiency traits and 12113 records for body weight gain traits were collected at Research Center of Special Domestic Animals, University ...
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This study was done in order to estimate genetic parameters of growth and feed efficiency traits in Japanese quail. The data set consisted of 7762 records for feed efficiency traits and 12113 records for body weight gain traits were collected at Research Center of Special Domestic Animals, University of Zabol. The following traits including body weight gain from 20 to 25, 25-30, 30-35, 35-40, 40-45 and from 0 to 45 days of age, feed intake, feed conversion ratio and residual feed intake from 20 to 45 days of age were evaluated. The genetic parameters were estimated through single and bivariate animal models via Gibbs sampling method. Heritability estimates for body weight gain varied from 0.02 to 0.23 and for feed intake, feed conversion ratio, residual feed intake was in ranges of 0.04 to 0.11. Genetic correlations estimates between body weight gain and feed conversion ratio 20-25, body weight gain and feed conversion ratio 25-30, body weight gain and feed conversion ratio 30-35, body weight gain and feed conversion ratio 35-40, body weight gain and feed conversion ratio 40-45 were -0.56, -0.49, -0.57, -0.70 and 0.25 respectively. Considering estimated genetic correlations of this study, we recommend that selection for body weight gain and decrease feed efficiency have potential to improve feed efficiency traits in Japanese quail. It is expected that by selecting for these traits the costs of breeding programs such as feeding and phenotyping would be reduced.
Ali Vojdan Hassan Kiyadeh; Mohammad Rokouei; Gholam Reza Dashab; Ahmad Reza Seyedalian; Hadi Faraji- Arough
Volume 21, Issue 2 , Summer 2019, , Pages 181-192
Abstract
This research was conducted with the aim of estimation of environmental factors affecting survival and estimate the genetic parameters survival from 1 to the last recording date in Zandi sheep. The survival records of 9558 Zandi sheep from 273 rams and 2328 ewes collected by Animal Breeding Center of ...
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This research was conducted with the aim of estimation of environmental factors affecting survival and estimate the genetic parameters survival from 1 to the last recording date in Zandi sheep. The survival records of 9558 Zandi sheep from 273 rams and 2328 ewes collected by Animal Breeding Center of Iran during the 25 years (1987 to 2011) were used in the analysis. The effective factors on survival and culling risk were estimated by Survival and cmprsk package. Estimation of variance components was performed by using of exponential distribution for censored dates by the fitting of model with additive genetic effect (model 1) and joint additive genetic and maternal permanent environmental of effects (model 2) under Bayesian approach and Gibbs sampling. A total of 1000000 samples with a burn-in of 100000 and a sampling interval of 75 were generated to estimate the posterior distribution of variance components. The results showed that year, month, birth weight, type birth, sex (P<0.001) and dam age (p<0.01) had significant effect on survival trait. the direct heritability of survival trait using models 1 and 2 was 0.184( 0.136-0.264) and 0.162( 0.120-0.202), respectively. the proportion of permanent variance to phenotypic variance was 0.046( 0.063- 0.031). According to the results of this study, genetic improvement of survival trait in zandi lamb is possible by genetic selection and the culling risk reduction is effective via management of environmental factors.
Maryam Arianfar; Mohammad Rokouei; Gholamreza Dashab; Hadi Faraji- Arough
Volume 20, Issue 3 , Autumn 2018, , Pages 351-363
Abstract
The objective of this study was to compare some nonlinear functions (Wood, Dhanoa, Wilmink, Ali-Schaeffer, Cappio Borlino, Cobby – Le Du, Dijkstra, Rook, Gous and Nelder) to describe the milk production curve of Iranian Holstein cattle. A dataset consisted of 6079976, 4879486 and 3312416 test-day ...
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The objective of this study was to compare some nonlinear functions (Wood, Dhanoa, Wilmink, Ali-Schaeffer, Cappio Borlino, Cobby – Le Du, Dijkstra, Rook, Gous and Nelder) to describe the milk production curve of Iranian Holstein cattle. A dataset consisted of 6079976, 4879486 and 3312416 test-day milk yield records related to first, second and third three lactation periods, respectively, from 3550 herds collecting by the Animal Breeding Center of Iran from 1983 to 2017, were used. The average of test day milk records for three lactation was 31.17, 34.08 and 33.83 kg, respectively. The nlme package of R software (version 3.4.3) was used for fitting nonlinear functions. The nonlinear functions were compared using four goodness of fit criteria, including Akaike’s information criterion (AIC), Bayesian information criterion (BIC), Root mean square error (RMSE) and Durbin-Watson index (DW). The Rook function showed the best fit for the milk production curve shape for three lactations in Iranian Holstein cattle when compared to other functions. The Gous and Rook functions showed the highest accuracy in predicting peak time, peak yield and persistency of milk production parameters in different lactations, but in general, the Rook function has a high predictive value in estimating the milk curve parameter descriptors.Therefore, Rook function is recommended for describing the milk production curve of Iranian Holstein cattle.
Raziyeh Rahimzadeh; Mohammad Rokouei; Hadi Faraji- Arough; Ali Maghsoudi; Behrooz Keshtegar
Volume 19, Issue 2 , Summer 2017, , Pages 299-310
Abstract
The aim of this study was to fit the best model for describing the egg production for Japanese quails at thirteen week of age. For this purpose, the daily egg production recordson 314 quails were used for the different models including nonlinear logistic, incomplete gamma, McNally, Lekhorst, Narushin ...
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The aim of this study was to fit the best model for describing the egg production for Japanese quails at thirteen week of age. For this purpose, the daily egg production recordson 314 quails were used for the different models including nonlinear logistic, incomplete gamma, McNally, Lekhorst, Narushin -Takma 2, McMillan and Nelder by R software. The best model was selected by some statics such as Mean square error (MSE), Akaike information criterion (AIC), Bayesian information criterion (BIC). The results showed that Narushin Takma 2 (minimum MSE, AIC and BIC) and Compartmental I Functions (maximum MSE, AIC and BIC) were the best and worst function to describe the egg production, respectively. The highest correlation (0.953) between predicted and actual values for the number of egg were obtained by Narushin -Takma 2 model. The results of the model comparisons and correlations indicate that Narushin - Takma 2 function describes Short- term egg production in quail better than other functions studied in this research and this function could be considered in a short- term prediction of the reproductive potential Japanese quail in breeding goals
Mohadeseh Namvar; Gholam Reza Dashab; Mohammad Rokouei; Hadi Faraji Arogh; Davoud Ali Saghi
Volume 19, Issue 2 , Summer 2017, , Pages 281-298
Abstract
This study was performed to compare different models for estimation of direct and maternal heritability and also for obtaining of genetic trend for body weight traits in Kurdi sheep of North Khorasan. The records of body weight in birth (BW, 7345 records), 3-month (3W, 5905 records), 6-month (6W ,5294 ...
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This study was performed to compare different models for estimation of direct and maternal heritability and also for obtaining of genetic trend for body weight traits in Kurdi sheep of North Khorasan. The records of body weight in birth (BW, 7345 records), 3-month (3W, 5905 records), 6-month (6W ,5294 records), 9-month (9W, 3800 records) and 12-month (12W, 3863 records) weight that collected during 1990 to 2013 by Sheep Breeding Station of Shirvan were used. Estimation of genetic parameters for different traits by using of six animal models was carried out by ThrGibbsf90 software. The most suitable model for each trait was determined based on Deviance Information Criterion (DIC). The estimates of direct heritability for BW, 3W, 6W, 9W and 12W traits were 0.172± 0.0007, .0.257± 0.0007, 0.351± 0.0006, 0.120± 0.0007 and 0.131± 0.0009, respectively. In this study, the material genetic effect was significant for BW, 3W and 6W traits (P<0.01) and proportion of maternal permanent environmental variance to phenotypic variance was varied from 0.055 (12W) to 0.186 (BW). Although estimated heritability of maternal effects for body weight was lower in older ages, the result of this study showed that including maternal effects (maternal genetic and permanent environmental effect) in the statistical model could lead to more accurate estimation of genetic parameters for growth traits in all ages. The phenotypic trend for BW, 3W, 6W, 9W and 12W were 8.4, 74.6, 8.3, 54.3, 78.3 gr/year, respectively and direct additive genetic trend for mentioned traits were -0.07, 14.2, -21.9, 13.7, 24.9 gr/year, respectively. Therefore, the results of bayesian analysis are more reliable than convientioal statistical methods.
Fatemeh Mir; Mohammad Rokouei; Gholamreza Dashab; Hadi Faraji- Arough
Volume 17, Issue 2 , Autumn 2015, , Pages 161-170
Abstract
The aim of this study was to design the base breeding plan in Sistani cattle by using of stochastic simulation. For this purpose, three population size (500, 1000, 2000 heads), three levels of herd number (5, 10, 20), two levels of selection intensity (high and low) and two levels of mating method (random ...
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The aim of this study was to design the base breeding plan in Sistani cattle by using of stochastic simulation. For this purpose, three population size (500, 1000, 2000 heads), three levels of herd number (5, 10, 20), two levels of selection intensity (high and low) and two levels of mating method (random and Minimum co-ancestry) were combined together and in total 36 scenarios were compared for 30 years. Results showed that the effect of all factors on the annual genetic gain for total merit, the annual genetic gain of birth weight (except in mating method and selection intensity) and yearling weight, the annual inbreeding rate (except in herd number), generation interval (except in mating method and selection intensity) and selection accuracy of sire and dames was significant. The annual genetic gain in high selection intensity, population size of 2000 and less number of herd (5 herds) was 8.5, 93.2 and 38 percent higher than low selection intensity, population size of 500 and more number of herd (20 herds). Despite having less total genetic gain (11 percent) in Minimum co-ancestry mating, the annual inbreeding rate in this mating method was 18 percent lower than random mating. The results of this study showed that less number of herd, large population size and high selection intensity considered in breeding plans of Sistani cattle and minimum co-ancestry mating used for control of population inbreeding.
Samane Abuli; Gholam Reza Dashab; Mohammad Rokouei; Mehdi Vafaei valeh
Volume 17, Issue 1 , Spring 2015, , Pages 107-117
Abstract
The polymorphism in exon three of FABP4 gene and its association with growth traits of 45 Sistani (n=30) and Dashtiari (n=15) cattle were investigated. DNA extraction from the whole blood was performed and its quality was determined by electrophoresis of one percent agarose gel. Animal genotypes were ...
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The polymorphism in exon three of FABP4 gene and its association with growth traits of 45 Sistani (n=30) and Dashtiari (n=15) cattle were investigated. DNA extraction from the whole blood was performed and its quality was determined by electrophoresis of one percent agarose gel. Animal genotypes were determined based on polymerase chain reaction (PCR) products and their band size electrophoresed on agarose 2.8 percent resulted from enzyme digestion by NlaIII. The pattern of bands showed three genotypes including AA, AB and BB in two Sistani and Dashtiari breeds with frequency of 67, 30 and three percent and 73, 27 and zero percent, respectively. The frequency of A and B alleles in exon three of FABP4 in Sistani and Dashtiari breeds were 82 and 18 percent and 86.5 and 13.5 percent, respectively. Heterozygosity indices including Shannon index (I), Nei’s index, observed and expected heterozygosity in Sistani and Dashtiari population were 48, 30, 30 and 30 percent and 39, 11, 27 and 24 percent, respectively. The association between genotypes and growth-related traits were significant for body weights in six, nine and 12 months of age. Therefore, this locus can be considered as a candidate gene in breeding programs for describing the variation of growth traits after weaning age in calves.