scholarly journals Estimation of Additive and Non-Additive Genetic Variances of Body Weight, Egg Weight and Egg Production for Quails (Coturnix coturnix japonica) with an Animal Model Analysis

2006 ◽  
Vol 49 (3) ◽  
pp. 300-307 ◽  
Author(s):  
N. Mielenz ◽  
R. R. Noor ◽  
L. Schüler

Abstract. This study estimates the additive and non-additive variances for egg production and body weight traits of two lines of quails from a long-term selection with the help of the REML method. For the body weight of 42-day-old females (BW42f) and males (BW42m), a total of 7,934 records for line 1 and 7,214 records for line 2 from 21 generations were used in our analyses. Additionally, 1,717 records of females from line 1 and 1,671 records of females from line 2 contained information on their egg production at an age of 42 to 200 days (EN200), on the average egg weight for the first 11 weeks of their laying season (EW1), on the average egg weight from weeks 12 to 23 (EW2), and on their body weight at an age of 200 days (BW200f). A multivariate additive animal model and one-trait dominance models, which include the inbreeding coefficients as covariates, were fitted to the data. The estimates of the heritability gained from our dominance models were smaller than those from the additive model. For line 1, the heritability values decreased for EN200 from 0.35 to 0.32, for EW1 from 0.66 to 0.56, for BW200f from 0.42 to 0.38, and for BW200m from 0.51 to 0.49, respectively. For the first line, the respective ratio (d2) of the dominance variance to the phenotypic variance for EN200, EW1, BW200f and BW200m was 0.08, 0.22, 0.09 and 0.21, and the values for the second line were 0.12, 0.06, 0.001 and 0.23.

Author(s):  
P. Chandan ◽  
T.K. Bhattacharya ◽  
U. Rajkumar ◽  
L.L.L. Prince ◽  
R.N. Chatterjee

Indian White Leghorn strain-IWK has been improved for higher egg weight as well as number over last twelve generations at ICAR-Directorate of Poultry Research, Hyderabad. The data collected on various economic traits of egg production were analyzed using REML approach of animal model. Current study showed that the heritability estimate of body weight, age at sexual maturity (ASM), egg numbers and egg weight was moderate to high, low to moderate, low and high, respectively. The body weight was positively correlated with egg weight but negatively correlated with egg numbers. The body weight at 16 and 20 weeks were negatively correlated with ASM and were very important for achieving early ASM. ASM was negatively correlated with egg numbers. The egg weight regressed as the egg number increased. The part period egg production EP52 was highly correlated with EP64; therefore EP52 can be used for selecting parents for higher egg number instead of EP64.


2003 ◽  
Vol 46 (1) ◽  
pp. 77-84
Author(s):  
N. Mielenz ◽  
M. Kovac ◽  
E. Groeneveld ◽  
R. Preisinger ◽  
M. Schmutz ◽  
...  

Abstract. Title of the paper: Genetic evaluation of egg production traits based on additive and dominance models in laying hens The study was conducted to estimate additive and dominance variances for egg production traits of two commercial purebred lines (A & D) of laying hens using an animal model analysis. Breeding values estimated from a dominance model were compared to those from an additive model. In total, 8625 records of line A and 8968 records of line D from three generations were used in the analysis. Every record contained information on the number of eggs laid between 20 and 28 (EN1-2), 28 and 48 (EN3-7) and between 20 and 48 (EN1-7) weeks of age. Further average egg weight (EW), egg weight at 28 (EW1), 33 (EW2) and 40 (EW3) weeks of age were available. An additive animal model and one- and three-trait dominance models including the inbreeding coefficients as covariates were fitted to the data. Simultaneous estimates of the additive and dominance variance components were obtained using the REML method. The estimates of h2 from the dominance models for EN1-2, EN3-7, EN1-7 and EW were 0.40, 0.15, 0.28 and 0.62 for line A and 0.38, 0.16, 0.26 and 0.53 for line D. The ratios d2 of the dominance variance to total variance were moderate for EN (0.12–0.13) and low for EW (0.04–0.07) within line A but relatively low for EN (0.03–0.12) and high for EW (0.12–0.21) within line D. Between the breeding values of the best 100 hens of each generation estimated with the additive and the dominance models for EN1-2, EN3-7, EN1-7 and EW high rank correlations (0.946, 0.896, 0.945 and 0.991 in line A and 0.996, 0.899, 0.971 and 0.951 in line D were found


2020 ◽  
Vol 33 (8) ◽  
pp. 1217-1223
Author(s):  
Jun Guo ◽  
Kehua Wang ◽  
Liang Qu ◽  
Taocun Dou ◽  
Meng Ma ◽  
...  

Objective: Eggshells with a uniform color and intensity are important for egg production because many consumers assess the quality of an egg according to the shell color. In the present study, we evaluated the influence of dominant effects on the variations in eggshell color after 32 weeks in a crossbred population.Methods: This study was conducted using 7,878 eggshell records from 2,626 hens. Heritability was estimated using a univariate animal model, which included inbreeding coefficients as a fixed effect and animal additive genetic, dominant genetic, and residuals as random effects. Genetic correlations were obtained using a bivariate animal model. The optimal diagnostic criteria identified in this study were: L* value (lightness) using a dominance model, and a* (redness), and b* (yellowness) value using an additive model.Results: The estimated heritabilities were 0.65 for shell lightness, 0.42 for redness, and 0.60 for yellowness. The dominance heritability was 0.23 for lightness. The estimated genetic correlations were 0.61 between lightness and redness, –0.84 between lightness and yellowness, and –0.39 between redness and yellowness.Conclusion: These results indicate that dominant genetic effects could help to explain the phenotypic variance in eggshell color, especially based on data from blue-shelled chickens. Considering the dominant genetic variation identified for shell color, this variation should be employed to produce blue eggs for commercial purposes using a planned mating system.


2017 ◽  
Vol 52 (2) ◽  
pp. 222
Author(s):  
M. Shanmugam ◽  
M. Niranjan ◽  
K. Rakesh ◽  
T.K. Bhattacharya ◽  
B.L.N. Reddy ◽  
...  

1998 ◽  
Vol 72 (2) ◽  
pp. 93-109 ◽  
Author(s):  
LUTZ BÜNGER ◽  
ULLA RENNE ◽  
GERHARD DIETL ◽  
SIEGFRIED KUHLA

Based on the outbred mouse strain Fzt: Du, which has been obtained by systematic crossing of four inbred and four outbred lines, a long-term selection experiment was carried out for total protein amount (PA) in the carcass, starting in 1975. An unselected control line (CO) was kept under the same management but without continuous protein analysis. The protein amount of male carcasses at 42 days of age (P42) increased from 2·9 g in generation 0 to 5·2 g at generation 70, representing 97% of a theoretical selection limit. The total selection response amounts to 2·3 g, which is about 80% above the initial value and corresponds to 9σp or 12σA . The estimated realized heritability of protein amount decreased from 0·56 to 0·03 at generation 70, which was due to an increase in phenotypic variance from 0·065 to 0·24 g2 and a reduction in genetic variance from 0·04 to 0·01 g2. Half the selection response was obtained after about 18 to 23 generations, a half-life of 0·25 to 0·3 Ne. The maximum selection response was 0·094 g/generation and the response was 0·01 g/generation at generation 70. The measurements of body weights at 0, 10, 21, 42 and 63 days throughout the experiment showed a strong correlated effect for all weights. The PA mice are one of the heaviest lines of mice ever reported, and do not differ significantly in their body composition from control mice at 42 days. The direct selection response was due primarily to increased general growth. Body weight and protein amount are phenotypically and genetically highly correlated (rp=0·82, rA≈1); however, selection for body weight led to fatter animals, whereas selection for protein opposed increased fatness (at least until selection age). This may be of general importance in animal breeding. The comparatively high selection response in this experiment seems due to the heterogeneity of the base population, the relatively high effective population size, and the duration of the experiment.


2014 ◽  
Vol 12 (1) ◽  
pp. 10-14
Author(s):  
MS Islam ◽  
H Khatun ◽  
MN Islam ◽  
S Faruque ◽  
MSK Sarker

A total of 887 ducklings of BLRI-1 duck genotype and 352 ducklings of BLRI-2 duck genotype were studied to measure productive and reproductive performances under intensive management. Data were recorded on body weight, egg production, egg weight, fertility, embryonic mortality, hatchability, feed intake, age at sexual maturity, body weight at maturity and egg weight at maturity. The fertility rate in BLRI-1duck was significantly (p<0.01) higher than that of BLRI-2 duck, while hatchability of BLRI-2 duck on fertile eggs were significantly (p<0.05) better compared to BLRI-1 duck. The embryonic mortality was significantly (p<0.01) higher in BLRI-2 duck than BLRI-1 duck. Duckling weight was influenced by egg weight (p<0.05) but difference in duckling: egg ratio was not significant (p>0.05). Hatching weight, 4th week and 12th week of age were significant (p<0.05) influent while the body weight of ducks at 8th week did not differ significantly (p>0.05) for BLRI-1 and BLRI-2 ducks, respectively. The least squares mean for age at sexual maturity were 158 days and 151.75 days, respectively for BLRI-1 and BLRI-2 ducks (p<0.05). BLRI-1 duck started to lay eggs almost one week late compared to BLRI-2 duck. Duck weight at sexual maturity, egg weight at first lay and egg production did not have significant (p>0.05) difference between genotypes. It may be concluded that BLRI-2 duck genotype is superior in terms of hatchability and age at sexual maturity to BLRI-1 duck genotype. DOI: http://dx.doi.org/10.3329/agric.v12i1.19485 The Agriculturists 2014; 12(1) 10-14


1996 ◽  
Vol 75 (10) ◽  
pp. 1180-1191 ◽  
Author(s):  
KARL E. NESTOR ◽  
D.O. NOBLE ◽  
J. ZHU ◽  
Y. MORITSU

2021 ◽  
Vol 28 (1) ◽  
pp. 1-8
Author(s):  
C. A. CHINEKE

Forty 76 weeks old Olympia Black layers were randomly selected, individually caged and intensively reared for a period of 16 weeks to study the effect of body weight on some egg production traits. The analysis of variance revealed significant effect of body weight on production traits investigated (P<0.01) except egg index (P>0.05). The correlation analysis showed that the body weight was positively and non-significantly (P>0.05) correlated with egg length, egg breadth, she'll weight, yolk weight, albumen weight, she'll thickness and significantly with egg weight (P<0.01) and negatively with egg index (r = 0.016). The second-degree (quadratic) equations for estimates of optimum 76 week body weights suggested 1.271 to 1.801 as required body weight range in kilograms for satisfactory performance. The body weight range at this age is attainable through breeding, good feeding and other management practices.


2016 ◽  
Vol 2 (2) ◽  
pp. 348-351
Author(s):  
Md Azharul Islam Talukder ◽  
Md Ashadul Alam ◽  
Md Moklesur Rahman ◽  
Md Abu Hemayet ◽  
Md Asadul Islam

A total of 115 hilly chickens (92 female and 23 males) and 35 naked neck hilly Chickens (28 females and 7 males) were reared in open sided poultry house for 10 months period to compare their productive and reproductive performances. The mean body weights of adult female and male hilly birds and naked neck hilly birds were 2244, 2005 and 2664, 2576 g respectively. The age at first egg of both type of birds were 147 and 159 days respectively and hen-day egg production were 27±1.4 and 35±3.3 respectively. The average egg weight was 41±4 and 38±3.6 g respectively. Both type of bird per day average feed consumption were 97.61±11 and 102±22 g and mortality were 15.56±3.7 and 11.42±2.7 percent respectively. The average hatchability percentage performed by 14 broody hens reared on litter floor was 67.5±10 and 57±22 percent respectively. The average hatching egg weight and chick weight were 47.28±3, 41.48±1 and 31.4±3, 29.6±4 g respectively. The body weight of growing hilly bird and Naked Neck hilly bird after eleven weeks of age were 727.3±17.4 and 645±97.6g, respectively and Feed conversion ratios (FCR) were 3.39 and 3.34 respectively. It was concluded that Hilly chicken improved by body weight than previous year and both feathered and Naked Neck Hilly chicken given an indication of meat type native chicken and required to reproduce to have large stock for undertaking conservation and further improvement programme.Asian J. Med. Biol. Res. June 2016, 2(2): 348-351


2020 ◽  
Vol 1 (1) ◽  
pp. 52-55
Author(s):  
Dinesh Mahto ◽  

Twenty farmers selected from each village for 6 villages of the district and skill based training on various aspects of backyard poultry farming. Participants enriched with sound knowledge were distributed with 25 Vanaraja & Grampriya chicks per person. The records of mean body weight of Grampriya and Vanaraja at different week interval. The body weight of crosses differ significantly (p < 0.05) after 4th week of age from their parents. The body weights of crosses were significantly (p < 0.05) higher than Hazra (Desi) birds and nearly similar to Vanaraja birds at different period of age attaining the sexual maturity in different groups of poultry birds. Vanaraja matures at the age of 141.62 days, Hazra (Desi) bird at 186.47 days and Grampriya at 158.32 days. The pullet egg weight of Vanaraja, Hazra (Desi) and Grampriya were 38.75, 30.82 and 34.94 g, egg weight at 40 weeks of age were 55.87, 42.89 and 51.26 g and increase in egg weight were 17.12, 12.07 and 15.42 g respectively. The hatchability percentages were 87.56%, 89.36% and 85.72% on fertile egg set and 68.23%, 68.92% and 64.74% on total egg set basis respectively in Vanaraja, Grampriya and local desi birds.


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