Background and Objective: Poultry industry aims mainly to produce genetically superior animals wi... more Background and Objective: Poultry industry aims mainly to produce genetically superior animals with high productivity of egg and meat. On a commercial scale, the purpose of most quail genetic improvement programs is to select genetically superior birds for meat and egg production. The objective of this study was to investigate the effect of short-term selection through four generations of selection in Japanese quail on egg number at the first 90 days of laying, estimate genetic parameters of egg production traits and estimate the correlated response to selection. Materials and Methods: Data of 1,352 female Japanese quails were collected through five consecutive generations (base and four selected generations) to estimate genetic gain, depending on breeding values, for Age at First Egg (AFE), Body Weight at Sexual Maturity (BWSM), Weight at First Egg (WFE), Egg Number at first 90 days (EN90D) and Average Egg Weight (AEW). Results: Estimates of heritability for egg production traits were ranged from 0.17 to 0.26. Moreover, positive genetic correlations were detected (0.18 to 0.43) between all studied egg production traits, except the correlation between AFE and EN90D (-0.32). The contrast among estimates was significant (p<0.05), favoring the selected generations over the base. The cumulative selection response was favorable for all unselected traits with the superiority of the selected generations to the base generation. Conclusions: It can be concluded that early selection based on breeding value for a cumulative egg number at first 90 days of egg production can effectively improve the total egg production and other egg traits in Japanese quail through four selected generations.
Objectives of the current study were to i) investigate effects of selection for bodyweight at fou... more Objectives of the current study were to i) investigate effects of selection for bodyweight at four weeks old on bodyweight (BW) and bodyweight gain (BWG) across four generations; ii) estimate correlated response to selection for BW and BWG at different ages; and iii) document best linear unbiased prediction (BLUP) of genetic trends for BW and BWG across four generations of selection. A total of 3540 chicks from 444 sires and 885 dams were used to estimate heritabilities, and genetic and phenotypic correlations for growth traits, including BW at 0, 2, 4, and 6 weeks, and BWG between 0 and 2, 2 and 4, 4 and 6, and 0 and 6 weeks. The selection effects, correlated responses and genetic trend for BW and BWG across generations were quantified by applying the animal model. Estimates of heritability for BW and BWG ranged from 0.22 to 0.42 and from 0.18 to 0.23, respectively. Ranges of genetic and phenotypic correlations for BW varied from 0.31 to 0.92 and 0.05 to 0.65, respectively. Moreover, estimates of genetic and phenotypic correlations for BWG at different ages were from 0.12 to 0.72 and 0.17 to 0.60, respectively. Bodyweight and BWG estimates after four generations of selection were significantly higher than those of the base generation. Moreover, contrasts of generation means were significant across the four generations. The genetic trends across the generations clarified that BLUP estimates for BW and BWG gradually increased with the advance of generations until the fourth generation.
Quantitative trait loci (QTL) affecting age at first egg (AFE), weight at first egg (WFE), 120-da... more Quantitative trait loci (QTL) affecting age at first egg (AFE), weight at first egg (WFE), 120-days of egg number (EN), egg weight (EW), Hugh unit (HU) and egg shell strength (ESS) were identified in F 2 intercross population produced by crossing males of Golden Montazah (M) with females of White Leghorn (L). Phenotypic data for egg traits of 4131 hens were analyzed using multi-traits animal model. For QTL analysis, 1011 hens of F 2 were genotyped using 45 genetic markers in nine autosomal linkage groups and Z chromosome and the mixed model including the fixed effects of hatch along with the additive and dominance effects of QTL as random effects was used. The total map length was 1949 cM and a total of 15 significant QTL were detected for egg traits and these QTL were distributed over four distinct regions on five chromosomes (2, 3, 4, 8 and Z). The QTL region on the Z chromosome was large and including QTL for AFW, EW, EN and ESS. The significant QTL were located on chromosomes 2, 4, 8 and Z for WFE at position of 322, 156, 61 and 102 cM; on the chromosomes 3 and Z for AFE at position of 189 and 128 cM, on the chromosomes 4 and Z sex chromosome for EW at position of 191 and 76 cM; on the chromosomes 4 and Z for EN at position of 55 and 89 cM; on the chromosomes 2, 4 and 8 for HU at position of 89, 222, and 18 cM; on Z sex chromosome for ESS at position of 97 cM, respectively. A total of four significant QTL were detected at 5 % chromosome-wise significance level, while a total of 11 significant QTL were detected at 1 % genomic-wise significance level and the total variances explained by QTL were 10.7, 12.2, 18.6, 12.2, 15.3 and 5 % for WFE, AFE, EW, EN, HU and ESS, respectively. The additive effects attributable to QTL explaining 5.4 to 53.0 % for WFE, 1.6 % for AFE, 4.4 to 8.2 % for EN, 3.0 to 6.5 % for EW,-0.6 and-6.2 % for Hu and-55.6 % for ESS of the total phenotypic variance of the F 2 population, while the dominance effects attributable to QTL explained 0.3 to 10.5, 4.0,-1.1 to-18.0,-1.6,-3.9 to-5.3 for WFE, AFE, EN, EW and HU, respectively.
A selection program for four generations (base and three selected generations) was started in 201... more A selection program for four generations (base and three selected generations) was started in 2011 at Benha University, Egypt to improve growth traits in a synthetic line named Benha chickens. A total of 18 cockerels and 180 pullets were selected according to their BLUP values for egg number during 90 days of laying from Benha base population (control). Data of 4916 chicks produced by 69 sires and 484 dams were used to estimate heritabiliets, genetic and phenotypic correlations and BLUP estimates for body weight at 0 (BW0), 4 (BW4), 8 (BW8), 12 (BW12) and 16 (BW16) weeks of age along with daily gains during 0-4 weeks (DG4), 4-8 weeks (DG8), 8-12 weeks (DG12) and 12-16 weeks (DG16). The selection effects, correlated responses and the genetic and phenotypic trends for body weights and daily gains across generations were quantified or clarified applying the updated approach of the animal model program of BLUPF90. Heritability estimates were moderate or high; being 0.52, 0.28, 0.27, 0.33 and 0.31 for BW0, BW4, BW8, BW12 and BW16, respectively. Genetic correlations for growth traits at different ages were positive and ranged from 0.64 to 0.88 among body weights, and from 0.14 to 0.65 among daily gain traits. The ranges in BLUP of most body weights and gains in the control generation were higher than those in the selected generations. Accuracies of BLUP estimates for growth traits in all generations (control and selected) were moderate or high. The three selected generations were superior (P <0.05) in most body weights and daily gains than the base generation and the contrasts among estimates of these generations were significant (P<0.05).The phenotypic trend increased from 33 to 34 g, 234 to 256 g, 532 to 650 g, 962 to 1123 g and 1458 to 1635 g for BW0, BW4, BW8, BW12 and BW16, respectively. the genetic trends across the generations clarifying that the initial BLUP estimates for BW0, BW4, BW8, BW12 and BW16 were 0, 1.0, 1.0, 1.4 and 0.1 g in the base population then gradually increased as the generation advanced till reached 0.1, 3.0, 9.5, 11 and 5.1 g in the first selected generation, 0.2, 5.0, 18, 20 and 9 g in the second selected generation, and 0.3, 7.0, 25, 29 and 13 g in the third selected generation, respectively. The accumulative correlated selection responses were 84 g for BW8, 123.6 g for BW12 and 123.6 g for BW16.
This project started in 2008 and aimed to produce a synthetic line of chickens under hot climate ... more This project started in 2008 and aimed to produce a synthetic line of chickens under hot climate conditions in Egypt. A description of the main features of the line Benha chickens (Line B) is carried out. It was founded in 2011 as a synthetic line between the Egyptian Golden Montazah (50%) and the White Leghorn (50 %). The procedure of foundation began mating Golden Montazah cocks to White Leghorn hens and it was followed by three generations of "inter se" mating. Afterwards the line has been selected to highly egg production and quality according to the predicted breeding values based the BLUP procedure using animal model. The phenotypic and productive characters for this line are recorded. The main characteristics of this line are: Feather colors in adult chickens were mostly White (70%), 15% red golden and 15% grey, good adaptation for hot climate conditions (25-35 o C). It has high resistance for Pasteurellosis and Salmonella diseases, high fertility (93%) and hatchability (86%), low mortality rate (1%) during the production period, moderate body weight at sexual maturity (1742 g) and age at sexual maturity 159.6 d, high annual egg production (230 egg), moderate egg weight (55 g), white egg color, egg shape index was 79.1%, high Haugh units (93.8 %), live body weight was 1970 g and 1269 g for males and females respectively, carcass weight was 1273 g for cocks and moderate dressing percentage (65%). Thus, the B-line has showed high productive traits under hot climate conditions in Egypt.
A selection program for four generations (base and three selected generations) was started in 201... more A selection program for four generations (base and three selected generations) was started in 2011 at Benha University, Egypt to improve growth traits in a synthetic line named Benha chickens. A total of 18 cockerels and 180 pullets were selected according to their BLUP values for egg number during 90 days of laying from Benha base population (control). Data of 4916 chicks produced by 69 sires and 484 dams were used to estimate heritabiliets, genetic and phenotypic correlations and BLUP estimates for body weight at 0 (BW0), 4 (BW4), 8 (BW8), 12 (BW12) and 16 (BW16) weeks of age along with daily gains during 0-4 weeks (DG4), 4-8 weeks (DG8), 8-12 weeks (DG12) and 12-16 weeks (DG16). The selection effects, correlated responses and the genetic and phenotypic trends for body weights and daily gains across generations were quantified or clarified applying the updated approach of the animal model program of BLUPF90. Heritability estimates were moderate or high; being 0.52, 0.28, 0.27, 0.33 and 0.31 for BW0, BW4, BW8, BW12 and BW16, respectively. Genetic correlations for growth traits at different ages were positive and ranged from 0.64 to 0.88 among body weights, and from 0.14 to 0.65 among daily gain traits. The ranges in BLUP of most body weights and gains in the control generation were higher than those in the selected generations. Accuracies of BLUP estimates for growth traits in all generations (control and selected) were moderate or high. The three selected generations were superior (P <0.05) in most body weights and daily gains than the base generation and the contrasts among estimates of these generations were significant (P<0.05).The phenotypic trend increased from 33 to 34 g, 234 to 256 g, 532 to 650 g, 962 to 1123 g and 1458 to 1635 g for BW0, BW4, BW8, BW12 and BW16, respectively. the genetic trends across the generations clarifying that the initial BLUP estimates for BW0, BW4, BW8, BW12 and BW16 were 0, 1.0, 1.0, 1.4 and 0.1 g in the base population then gradually increased as the generation advanced till reached 0.1, 3.0, 9.5, 11 and 5.1 g in the first selected generation, 0.2, 5.0, 18, 20 and 9 g in the second selected generation, and 0.3, 7.0, 25, 29 and 13 g in the third selected generation, respectively. The accumulative correlated selection responses were 84 g for BW8, 123.6 g for BW12 and 123.6 g for BW16.
A selection program for four generations (base and three selected generations) was started in 201... more A selection program for four generations (base and three selected generations) was started in 2011 in Benha University, Egypt to improve egg production traits in a synthetic line named Benha chickens. A total of 18 cockerels and 180 pullets were selected from Benha base population (control) according to their BLUP values for egg number during 90 days of laying Data of 756 pedigreed hens were used to obtain estimates of heritability, genetic and phenotypic correlations and BLUP for egg production traits, age (ASM) and body weight at sexual maturity (BWSM), weight of the first egg (WFE), egg number (EN), rate of laying (RL), egg mass (EM) recorded during 90 days (EM90D) and 120 days (EM120D) of production after sexual maturity. The selection effects, correlated responses and the genetic and phenotypic trends for egg production traits across generations were quantified and clarified applying the updated approach of the animal model program of BLUPF90. Heritability estimates were moderate; being 0.27, 0.32, 0.42, 0.31, 0.34, 0.28, 0.33, 0.14 and 0.19 for ASM, BWSM, WFE, EN90D, EM90D, EN120D, EM120D, RL90D and RL120D, respectively. The ranges in BLUP of most egg production traits in the control generation were higher than those estimates in the selected generations. Accuracies of BLUP estimates for egg production traits in all generations (control and selected) were moderate or high. The three selected generations were superior in most egg production traits than the base generation (P <0.05) and the contrasts among estimates of these generations were significant (P<0.05). The phenotypic trend increased from 1642 to 1759 g, 28.1 to 30.2 g, 57 to 64 egg, 79 to 84 egg, 2593 to 2977g and 3651 to 4027 g for BWSM, WFE, EN90D, EN120D, EM90D and EM120D, respectively. The genetic trends across the generations clarifying that the initial BLUP estimates for BWSM, WFE, EN90D, EN120, EM90D, EM120D were 12 g, 0.07 g, 0.9 egg, 0.5 egg, 0.57 g and 38 g in the base generation, then gradually increasing as the generation of selection advanced till reached 21 g, 0.03 g, 2 egg, 2.2 egg, 72g and 63 g in the first generation, and reached 32 g, 0.52 g, 3.4 egg, 4 egg, 87 g and 89 g in the second generation and finally 45 g, 0.8 g, 4.8 egg, 5.5 egg, 102 g and 114g in the third generation, respectively. The accumulative correlated selection responses were 140.5 g, 1.99 g, 5.45 egg, 418 g, 371g, 7.52 % and 4.22 % for BWSM, WFE, EN120D, EM90D, EM120D, RL90D and RL120D, respectively.
Background and Objective: Poultry industry aims mainly to produce genetically superior animals wi... more Background and Objective: Poultry industry aims mainly to produce genetically superior animals with high productivity of egg and meat. On a commercial scale, the purpose of most quail genetic improvement programs is to select genetically superior birds for meat and egg production. The objective of this study was to investigate the effect of short-term selection through four generations of selection in Japanese quail on egg number at the first 90 days of laying, estimate genetic parameters of egg production traits and estimate the correlated response to selection. Materials and Methods: Data of 1,352 female Japanese quails were collected through five consecutive generations (base and four selected generations) to estimate genetic gain, depending on breeding values, for Age at First Egg (AFE), Body Weight at Sexual Maturity (BWSM), Weight at First Egg (WFE), Egg Number at first 90 days (EN90D) and Average Egg Weight (AEW). Results: Estimates of heritability for egg production traits were ranged from 0.17 to 0.26. Moreover, positive genetic correlations were detected (0.18 to 0.43) between all studied egg production traits, except the correlation between AFE and EN90D (-0.32). The contrast among estimates was significant (p<0.05), favoring the selected generations over the base. The cumulative selection response was favorable for all unselected traits with the superiority of the selected generations to the base generation. Conclusions: It can be concluded that early selection based on breeding value for a cumulative egg number at first 90 days of egg production can effectively improve the total egg production and other egg traits in Japanese quail through four selected generations.
Objectives of the current study were to i) investigate effects of selection for bodyweight at fou... more Objectives of the current study were to i) investigate effects of selection for bodyweight at four weeks old on bodyweight (BW) and bodyweight gain (BWG) across four generations; ii) estimate correlated response to selection for BW and BWG at different ages; and iii) document best linear unbiased prediction (BLUP) of genetic trends for BW and BWG across four generations of selection. A total of 3540 chicks from 444 sires and 885 dams were used to estimate heritabilities, and genetic and phenotypic correlations for growth traits, including BW at 0, 2, 4, and 6 weeks, and BWG between 0 and 2, 2 and 4, 4 and 6, and 0 and 6 weeks. The selection effects, correlated responses and genetic trend for BW and BWG across generations were quantified by applying the animal model. Estimates of heritability for BW and BWG ranged from 0.22 to 0.42 and from 0.18 to 0.23, respectively. Ranges of genetic and phenotypic correlations for BW varied from 0.31 to 0.92 and 0.05 to 0.65, respectively. Moreover, estimates of genetic and phenotypic correlations for BWG at different ages were from 0.12 to 0.72 and 0.17 to 0.60, respectively. Bodyweight and BWG estimates after four generations of selection were significantly higher than those of the base generation. Moreover, contrasts of generation means were significant across the four generations. The genetic trends across the generations clarified that BLUP estimates for BW and BWG gradually increased with the advance of generations until the fourth generation.
Quantitative trait loci (QTL) affecting age at first egg (AFE), weight at first egg (WFE), 120-da... more Quantitative trait loci (QTL) affecting age at first egg (AFE), weight at first egg (WFE), 120-days of egg number (EN), egg weight (EW), Hugh unit (HU) and egg shell strength (ESS) were identified in F 2 intercross population produced by crossing males of Golden Montazah (M) with females of White Leghorn (L). Phenotypic data for egg traits of 4131 hens were analyzed using multi-traits animal model. For QTL analysis, 1011 hens of F 2 were genotyped using 45 genetic markers in nine autosomal linkage groups and Z chromosome and the mixed model including the fixed effects of hatch along with the additive and dominance effects of QTL as random effects was used. The total map length was 1949 cM and a total of 15 significant QTL were detected for egg traits and these QTL were distributed over four distinct regions on five chromosomes (2, 3, 4, 8 and Z). The QTL region on the Z chromosome was large and including QTL for AFW, EW, EN and ESS. The significant QTL were located on chromosomes 2, 4, 8 and Z for WFE at position of 322, 156, 61 and 102 cM; on the chromosomes 3 and Z for AFE at position of 189 and 128 cM, on the chromosomes 4 and Z sex chromosome for EW at position of 191 and 76 cM; on the chromosomes 4 and Z for EN at position of 55 and 89 cM; on the chromosomes 2, 4 and 8 for HU at position of 89, 222, and 18 cM; on Z sex chromosome for ESS at position of 97 cM, respectively. A total of four significant QTL were detected at 5 % chromosome-wise significance level, while a total of 11 significant QTL were detected at 1 % genomic-wise significance level and the total variances explained by QTL were 10.7, 12.2, 18.6, 12.2, 15.3 and 5 % for WFE, AFE, EW, EN, HU and ESS, respectively. The additive effects attributable to QTL explaining 5.4 to 53.0 % for WFE, 1.6 % for AFE, 4.4 to 8.2 % for EN, 3.0 to 6.5 % for EW,-0.6 and-6.2 % for Hu and-55.6 % for ESS of the total phenotypic variance of the F 2 population, while the dominance effects attributable to QTL explained 0.3 to 10.5, 4.0,-1.1 to-18.0,-1.6,-3.9 to-5.3 for WFE, AFE, EN, EW and HU, respectively.
A selection program for four generations (base and three selected generations) was started in 201... more A selection program for four generations (base and three selected generations) was started in 2011 at Benha University, Egypt to improve growth traits in a synthetic line named Benha chickens. A total of 18 cockerels and 180 pullets were selected according to their BLUP values for egg number during 90 days of laying from Benha base population (control). Data of 4916 chicks produced by 69 sires and 484 dams were used to estimate heritabiliets, genetic and phenotypic correlations and BLUP estimates for body weight at 0 (BW0), 4 (BW4), 8 (BW8), 12 (BW12) and 16 (BW16) weeks of age along with daily gains during 0-4 weeks (DG4), 4-8 weeks (DG8), 8-12 weeks (DG12) and 12-16 weeks (DG16). The selection effects, correlated responses and the genetic and phenotypic trends for body weights and daily gains across generations were quantified or clarified applying the updated approach of the animal model program of BLUPF90. Heritability estimates were moderate or high; being 0.52, 0.28, 0.27, 0.33 and 0.31 for BW0, BW4, BW8, BW12 and BW16, respectively. Genetic correlations for growth traits at different ages were positive and ranged from 0.64 to 0.88 among body weights, and from 0.14 to 0.65 among daily gain traits. The ranges in BLUP of most body weights and gains in the control generation were higher than those in the selected generations. Accuracies of BLUP estimates for growth traits in all generations (control and selected) were moderate or high. The three selected generations were superior (P <0.05) in most body weights and daily gains than the base generation and the contrasts among estimates of these generations were significant (P<0.05).The phenotypic trend increased from 33 to 34 g, 234 to 256 g, 532 to 650 g, 962 to 1123 g and 1458 to 1635 g for BW0, BW4, BW8, BW12 and BW16, respectively. the genetic trends across the generations clarifying that the initial BLUP estimates for BW0, BW4, BW8, BW12 and BW16 were 0, 1.0, 1.0, 1.4 and 0.1 g in the base population then gradually increased as the generation advanced till reached 0.1, 3.0, 9.5, 11 and 5.1 g in the first selected generation, 0.2, 5.0, 18, 20 and 9 g in the second selected generation, and 0.3, 7.0, 25, 29 and 13 g in the third selected generation, respectively. The accumulative correlated selection responses were 84 g for BW8, 123.6 g for BW12 and 123.6 g for BW16.
This project started in 2008 and aimed to produce a synthetic line of chickens under hot climate ... more This project started in 2008 and aimed to produce a synthetic line of chickens under hot climate conditions in Egypt. A description of the main features of the line Benha chickens (Line B) is carried out. It was founded in 2011 as a synthetic line between the Egyptian Golden Montazah (50%) and the White Leghorn (50 %). The procedure of foundation began mating Golden Montazah cocks to White Leghorn hens and it was followed by three generations of "inter se" mating. Afterwards the line has been selected to highly egg production and quality according to the predicted breeding values based the BLUP procedure using animal model. The phenotypic and productive characters for this line are recorded. The main characteristics of this line are: Feather colors in adult chickens were mostly White (70%), 15% red golden and 15% grey, good adaptation for hot climate conditions (25-35 o C). It has high resistance for Pasteurellosis and Salmonella diseases, high fertility (93%) and hatchability (86%), low mortality rate (1%) during the production period, moderate body weight at sexual maturity (1742 g) and age at sexual maturity 159.6 d, high annual egg production (230 egg), moderate egg weight (55 g), white egg color, egg shape index was 79.1%, high Haugh units (93.8 %), live body weight was 1970 g and 1269 g for males and females respectively, carcass weight was 1273 g for cocks and moderate dressing percentage (65%). Thus, the B-line has showed high productive traits under hot climate conditions in Egypt.
A selection program for four generations (base and three selected generations) was started in 201... more A selection program for four generations (base and three selected generations) was started in 2011 at Benha University, Egypt to improve growth traits in a synthetic line named Benha chickens. A total of 18 cockerels and 180 pullets were selected according to their BLUP values for egg number during 90 days of laying from Benha base population (control). Data of 4916 chicks produced by 69 sires and 484 dams were used to estimate heritabiliets, genetic and phenotypic correlations and BLUP estimates for body weight at 0 (BW0), 4 (BW4), 8 (BW8), 12 (BW12) and 16 (BW16) weeks of age along with daily gains during 0-4 weeks (DG4), 4-8 weeks (DG8), 8-12 weeks (DG12) and 12-16 weeks (DG16). The selection effects, correlated responses and the genetic and phenotypic trends for body weights and daily gains across generations were quantified or clarified applying the updated approach of the animal model program of BLUPF90. Heritability estimates were moderate or high; being 0.52, 0.28, 0.27, 0.33 and 0.31 for BW0, BW4, BW8, BW12 and BW16, respectively. Genetic correlations for growth traits at different ages were positive and ranged from 0.64 to 0.88 among body weights, and from 0.14 to 0.65 among daily gain traits. The ranges in BLUP of most body weights and gains in the control generation were higher than those in the selected generations. Accuracies of BLUP estimates for growth traits in all generations (control and selected) were moderate or high. The three selected generations were superior (P <0.05) in most body weights and daily gains than the base generation and the contrasts among estimates of these generations were significant (P<0.05).The phenotypic trend increased from 33 to 34 g, 234 to 256 g, 532 to 650 g, 962 to 1123 g and 1458 to 1635 g for BW0, BW4, BW8, BW12 and BW16, respectively. the genetic trends across the generations clarifying that the initial BLUP estimates for BW0, BW4, BW8, BW12 and BW16 were 0, 1.0, 1.0, 1.4 and 0.1 g in the base population then gradually increased as the generation advanced till reached 0.1, 3.0, 9.5, 11 and 5.1 g in the first selected generation, 0.2, 5.0, 18, 20 and 9 g in the second selected generation, and 0.3, 7.0, 25, 29 and 13 g in the third selected generation, respectively. The accumulative correlated selection responses were 84 g for BW8, 123.6 g for BW12 and 123.6 g for BW16.
A selection program for four generations (base and three selected generations) was started in 201... more A selection program for four generations (base and three selected generations) was started in 2011 in Benha University, Egypt to improve egg production traits in a synthetic line named Benha chickens. A total of 18 cockerels and 180 pullets were selected from Benha base population (control) according to their BLUP values for egg number during 90 days of laying Data of 756 pedigreed hens were used to obtain estimates of heritability, genetic and phenotypic correlations and BLUP for egg production traits, age (ASM) and body weight at sexual maturity (BWSM), weight of the first egg (WFE), egg number (EN), rate of laying (RL), egg mass (EM) recorded during 90 days (EM90D) and 120 days (EM120D) of production after sexual maturity. The selection effects, correlated responses and the genetic and phenotypic trends for egg production traits across generations were quantified and clarified applying the updated approach of the animal model program of BLUPF90. Heritability estimates were moderate; being 0.27, 0.32, 0.42, 0.31, 0.34, 0.28, 0.33, 0.14 and 0.19 for ASM, BWSM, WFE, EN90D, EM90D, EN120D, EM120D, RL90D and RL120D, respectively. The ranges in BLUP of most egg production traits in the control generation were higher than those estimates in the selected generations. Accuracies of BLUP estimates for egg production traits in all generations (control and selected) were moderate or high. The three selected generations were superior in most egg production traits than the base generation (P <0.05) and the contrasts among estimates of these generations were significant (P<0.05). The phenotypic trend increased from 1642 to 1759 g, 28.1 to 30.2 g, 57 to 64 egg, 79 to 84 egg, 2593 to 2977g and 3651 to 4027 g for BWSM, WFE, EN90D, EN120D, EM90D and EM120D, respectively. The genetic trends across the generations clarifying that the initial BLUP estimates for BWSM, WFE, EN90D, EN120, EM90D, EM120D were 12 g, 0.07 g, 0.9 egg, 0.5 egg, 0.57 g and 38 g in the base generation, then gradually increasing as the generation of selection advanced till reached 21 g, 0.03 g, 2 egg, 2.2 egg, 72g and 63 g in the first generation, and reached 32 g, 0.52 g, 3.4 egg, 4 egg, 87 g and 89 g in the second generation and finally 45 g, 0.8 g, 4.8 egg, 5.5 egg, 102 g and 114g in the third generation, respectively. The accumulative correlated selection responses were 140.5 g, 1.99 g, 5.45 egg, 418 g, 371g, 7.52 % and 4.22 % for BWSM, WFE, EN120D, EM90D, EM120D, RL90D and RL120D, respectively.
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Papers by mahmoud elatrouny
On a commercial scale, the purpose of most quail genetic improvement programs is to select genetically superior birds for meat and egg
production. The objective of this study was to investigate the effect of short-term selection through four generations of selection in
Japanese quail on egg number at the first 90 days of laying, estimate genetic parameters of egg production traits and estimate the
correlated response to selection. Materials and Methods: Data of 1,352 female Japanese quails were collected through five consecutive
generations (base and four selected generations) to estimate genetic gain, depending on breeding values, for Age at First Egg (AFE), Body
Weight at Sexual Maturity (BWSM), Weight at First Egg (WFE), Egg Number at first 90 days (EN90D) and Average Egg Weight (AEW).
Results: Estimates of heritability for egg production traits were ranged from 0.17 to 0.26. Moreover, positive genetic correlations were
detected (0.18 to 0.43) between all studied egg production traits, except the correlation between AFE and EN90D (-0.32). The contrast
among estimates was significant (p<0.05), favoring the selected generations over the base. The cumulative selection response was
favorable for all unselected traits with the superiority of the selected generations to the base generation. Conclusions: It can be concluded
that early selection based on breeding value for a cumulative egg number at first 90 days of egg production can effectively improve the
total egg production and other egg traits in Japanese quail through four selected generations.
On a commercial scale, the purpose of most quail genetic improvement programs is to select genetically superior birds for meat and egg
production. The objective of this study was to investigate the effect of short-term selection through four generations of selection in
Japanese quail on egg number at the first 90 days of laying, estimate genetic parameters of egg production traits and estimate the
correlated response to selection. Materials and Methods: Data of 1,352 female Japanese quails were collected through five consecutive
generations (base and four selected generations) to estimate genetic gain, depending on breeding values, for Age at First Egg (AFE), Body
Weight at Sexual Maturity (BWSM), Weight at First Egg (WFE), Egg Number at first 90 days (EN90D) and Average Egg Weight (AEW).
Results: Estimates of heritability for egg production traits were ranged from 0.17 to 0.26. Moreover, positive genetic correlations were
detected (0.18 to 0.43) between all studied egg production traits, except the correlation between AFE and EN90D (-0.32). The contrast
among estimates was significant (p<0.05), favoring the selected generations over the base. The cumulative selection response was
favorable for all unselected traits with the superiority of the selected generations to the base generation. Conclusions: It can be concluded
that early selection based on breeding value for a cumulative egg number at first 90 days of egg production can effectively improve the
total egg production and other egg traits in Japanese quail through four selected generations.