Genetic parameters for egg weight v. age curve, and other egg production and egg weight traits, in synthetic lines of chickens

1983 ◽  
Vol 34 (1) ◽  
pp. 85 ◽  
Author(s):  
BH Yoo ◽  
BL Sheldon ◽  
RN Podger
Keyword(s):  
Standard Deviation ◽  
Genetic Correlation ◽  
Egg Production ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Egg Mass ◽  
Control Line ◽  
Egg Weight ◽  
Egg Number ◽  
Selection For

An exponential curve, W = P-Qexp(- Rt), where W is egg weight at age t, was fitted to egg weights of individual pullets, and genetic parameters were estimated for P, Q and R, the residual standard deviation and other egg weight and egg production characters. The data consisted of records collected over six generations on more than 4000 pullets in two selection lines and a control line which originated from a synthetic gene pool of White Leghorn x Australorp crosses. The half-sib and offspring-on-parent regression estimates of heritability pooled over the lines were 0.23 and 0.33 for P, 0.14 and 0.20 for Q, and 0.14 and 0.25 for R. Genetic correlations were estimated to be -0.10 between P and Q, -0.46 between P and R, and 0.90 between Q and R. These estimates suggest that the egg weight v. age curve may be modified to increase the proportion of eggs in desirable weight grades and reduce the incidence of oversized eggs later in the production year. The genetic correlation between mean weight of first 10 eggs and egg weight at 62 weeks of age was estimated to be 0.68, further suggesting that early egg weight may be improved partly independently of late egg weight. The heritability estimates of egg mass output were not higher than those of egg number in spite of the highly heritable average egg weight being an important component of egg mass, probably because of the negative genetic correlation (r = -0.49) between egg number and average egg weight. The standard deviation of individual pullet's egg weights was moderately heritable and genetically correlated positively with egg weight characters and negatively with egg production; these estimates were consistent with the responses to selection for reduced egg weight variability observed elsewhere

scholarly journals Direct and correlated responses to selection in two flocks of White Leghorn

1999 ◽  
Vol 42 (4) ◽  
pp. 403-414
Author(s):  
G. S. Brah ◽  
M. L. Chaudhary ◽  
J. S. Sandhu
Keyword(s):  
Egg Production ◽  
Production Efficiency ◽  
Efficiency Index ◽  
Egg Mass ◽  
Control Line ◽  
Correlated Responses ◽  
Egg Weight ◽  
Egg Number ◽  
Realized Genetic Gains ◽  
D 20

Abstract. Data on 17,588 pulletes of two strains selected for egg number and egg weight along with a control line were examined over seven generations. Significant desirable realized genetic gains/generation were observed for egg number to 40 weeks (2.18 and 2.23 eggs) and egg weight (0.81 and 0.45g) in both the strains. Significant correlated responses were also observed in age at first egg (−1.54 and −1.17 d); 20 and 40 week body weights (8.8 to 19.0). Significant desirable responses were also observed for egg mass (175 and 151g), rate of lay (1.0 and 1.37%), egg production efficiency (0.08 and 0.07) and efficiency index (1.09 and 1.03 g/d/kg) Natural selection did not seem to play any role. Inbreeding of 0.28 to 0.45% per generation did not appear to be of any significance in affecting the performance and heritabilities. The additive genetic and phenotypic variances and heritabilities remained stable over generations. Realized heritabilities varied between 0 18 and 0.29 for egg number and between 0.44 and 0.66 for egg weight and indicated the effectiveness of the criterion of selection.

scholarly journals PSVIII-38 Late-Breaking Abstract: Estimating genetic parameters of feed efficiency traits in American mink

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 347-347
Author(s):  
Pourya Davoudi ◽  
Duy Ngoc Do ◽  
Guoyu Hu ◽  
Siavash Salek Ardestani ◽  
Younes Miar
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
American Mink ◽  
Genetic Correlations ◽  
Final Body Weight ◽  
Selection For

Abstract Feed cost is the major input cost in the mink industry and thus improvement of feed efficiency through selection for high feed efficient mink is necessary for the mink farmers. The objective of this study was to estimate the heritability, phenotypic and genetic correlations for different feed efficiency measures, including final body weight (FBW), daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR) and residual feed intake (RFI). For this purpose, 1,088 American mink from the Canadian Center for Fur Animal Research at Dalhousie Faculty of Agriculture were recorded for daily feed intake and body weight from August 1 to November 14 in 2018 and 2019. The univariate models were used to test the significance of sex, birth year and color as fixed effects, and dam as a random effect. Genetic parameters were estimated via bivariate models using ASReml-R version 4. Estimates of heritabilities (±SE) were 0.41±0.10, 0.37±0.11, 0.33±0.14, 0.24±0.09 and 0.22±0.09 for FBW, DFI, ADG, FCR and RFI, respectively. The genetic correlation (±SE) was moderate to high between FCR and RFI (0.68±0.15) and between FCR and ADG (-0.86±0.06). In addition, RFI had low non-significant (P > 0.05) genetic correlations with ADG (0.04 ± 0.26) and BW (0.16 ± 0.24) but significant (P < 0.05) high genetic correlation with DFI (0.74 ± 0.11) indicating that selection for lower RFI will reduce feed intake without adverse effects on the animal size and growth rate. The results suggested that RFI can be implemented in genetic/genomic selection programs to reduce feed intake in the mink production system.

scholarly journals Genetic parameters for egg production traits in crosses between local and exotic chickens estimated by Bayesian inference

2021 ◽  
Vol 44 (3) ◽  
pp. 1-8
Author(s):  
I. Udeh ◽  
S. I. Omeje
Keyword(s):  
Egg Production ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Breeding Value ◽  
Appreciable Amount ◽  
Production Traits ◽  
Base Population ◽  
Egg Weight ◽  
Highest Posterior Density ◽  
Selection Of

Estimates of genetic parameters for economic traits are important to enable the breeder estimate the breeding value of individuals available for selection. Thus, this study was carried out to estimate genetic parameters namely heritability and genetic correlations among egg production traits in two strain crosses using bivariate animal model in Bayesian (MCMC) method. The egg production data were obtained from four generations which comprised the base population of two commercial egg strains and the local chicken, the inbred population derived from the base population, the F1 crossbred population obtained from the crossing of the local and exotic inbred chickens and the backcross population obtained from the backcrossing of the crossbred to their parents. A total number of 1,138 daughters of 62 sires and 620 dams were used for the study. The autocorrelations among samples in the MCMC chain were less than 0.1 for all lag values indicating that all samples of the posterior distribution were independent. The estimated heritability for age at first egg, body weight at first egg, hen day egg number, weight of first egg, egg weight at thirty week and egg weight at forty week were 0.62, 0.48, 0.47, 0.53, 0.54 and 0.56 for strain 1 crosses and 0.43, 0.48, 0.49, 0.52, 0.52 and 0.53 for strain 2 crosses. The corresponding highest posterior density interval ranged from 0.22 to 0.91 for strain 1 crosses and 0.07 to 0.83 for strain 2 crosses. The genetic correlations among egg production traits ranged from 0.06 to 1.97 in strain 1 and 0.06 to 2.59 in strain 2 crosses. The estimates were within the range reported in literature for egg production traits in chicken and imply that appreciable amount of additive genes exist in the strain crosses which could be used for the selection of superior birds. The magnitude of genetic correlations implies that selection of one trait could lead to correlated response to the other traits.

scholarly journals Two-trait Selection and the Genetic Correlation II. Changes in the Genetic Correlation During Two-trait Selection

1974 ◽  
Vol 27 (1) ◽  
pp. 89 ◽  
Author(s):  
AK Sheridan ◽  
JSF Barker
Keyword(s):  
Genetic Correlation ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Experimental Information ◽  
Base Population ◽  
Negative Change ◽  
Quantitative Characters ◽  
Bristle Number ◽  
Independent Culling ◽  
Selection For

Although there is little experimental information on the effect of simultaneous selection for two quantitative characters on the magnitude of the genetic correlation between them, it is apparently generally expected that such selection for the two characters in the same direction will cause a negative change in the genetic correlation, and selection in opposite directions a positive change. Selection using independent culling levels was done for each of the four combinations of high or low third coxal bristle number with high or low sternopleural bristle number in Drosophila melanogaster for 22 generations. To estimate changes in the genetic correlation, realized genetic parameters were estimated from single-trait lines started from the base population, and from the two-trait lines after 10 and 22 generations of selection. Changes in the genetic correlation in individual two-trait selection lines were variable and unpredictable. At generation 22 concurrent two-trait selection had resulted in significantly larger realized genetic correlations than divergent two-trait selection, so that results were contrary to the generally accepted expectation.

Genetic parameters for a heavy female turkey line

2005 ◽  
Vol 2005 ◽  
pp. 9-9
Author(s):  
A. D. Kranis ◽  
J. A. Woolliams ◽  
W. G. Hill ◽  
P. M. Hocking
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Genetic Parameters ◽  
Selection Criterion ◽  
Breast Muscle ◽  
Commercial Company ◽  
Egg Number ◽  
Research Population ◽  
Simultaneous Selection ◽  
Selection For

The major selection criterion in the turkey breeding industry is increased breast muscle and body weight in order to adapt to market demands. In female lines a dual selection for both body weight and egg production is performed. However, most published estimates indicate a variable correlation between growth and egg number (Nestor et al., 1996) and so the challenge posed is how to best to select for those opposing goals. The objective of this study was to investigate the effects of simultaneous selection for body weight and egg number by estimating the genetic parameters for a research population held by a commercial company in two different locations.

Egg production and certain behavioural characteristics and mortality pattern of indigenous chicken of India

2016 ◽  
Vol 59 ◽  
pp. 27-36
Author(s):  
P.G. Kumar ◽  
R.R. Churchil ◽  
A. Jalaludeen ◽  
K. Narayanankutty ◽  
P.A. Peethambaran ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Egg Production ◽  
Egg Mass ◽  
Indigenous Chicken ◽  
Mortality Pattern ◽  
Egg Weight ◽  
Behavioural Characteristics ◽  
Body Weights ◽  
Egg Number ◽  
Production Characteristics

Summary A survey to document the behaviour characteristics and mortality pattern of indigenous chicken of Kerala and a field egg recording study to record egg production characteristics of these birds were conducted. Flight distance and height was 13.29 and 3.97 m, respectively. The territory radius of cocks was 121.15 m. The chick survivability at 4 weeks of age was 64.98 percent. The day-old and 8th week body weights were 28.83 and 347.24 g, respectively. The 20th and 40th week body weight of males were 1,428.42 and 1,936.67 g and that of females were 1,114.04 and 1,445.63 g, respectively. The mortality up to 72 weeks was 69.38 percent and major cause of mortality during chick, grower and layer stage were mongoose (44.63 percent), wolf (24.29 percent) and diseases (52.18 percent) respectively. The fertility was 71.22 percent and hatchability on total and fertile egg set were 62.26 and 87.42 percent, respectively. There were 2.13 clutches in a laying cycle with inter-clutch intervals of 1.11 days. The average clutch size and number of eggs per cycle were 7.27 and 14.32, respectively. The egg number up to 72 weeks on hen-day and hen-housed basis was 116.81 and 85.84, respectively and the eggs were laid in 7.7 cycles. The age at first egg and average age at sexual maturity were 155 and 199.26 days, respectively. The egg weight at 28, 40 and 72 weeks of age was 37.80, 40.74 and 43.31 g, respectively, and egg mass per bird was 4,659.04 g. The broodiness and incubation pause were 26.03 and 121.75 days, respectively.

scholarly journals NET GENETIC AND TEMPORARY EPISTATIC OR MATERNAL ENVIRONMENTAL RESPONSES TO SELECTION FOR EGG PRODUCTION IN CHICKENS

Genetics ◽  
1981 ◽  
Vol 99 (2) ◽  
pp. 309-321
Author(s):  
G L Bennett ◽  
G E Dickerson ◽  
R S Gowe ◽  
A J McAllister ◽  
J A B Emsley
Keyword(s):  
Egg Production ◽  
Transmitted Disease ◽  
Selection Response ◽  
Egg Mass ◽  
Mass Selection ◽  
Total Response ◽  
Egg Weight ◽  
Egg Masses ◽  
Egg Number ◽  
Maternal Responses

ABSTRACT The difference between progeny from selected and unselected parents (T) was experimentally partitioned into net genetic change (GA), temporary favorable epistatic combinations (GEP) and egg-transmitted maternal environment (M) in two strains of Leghorns selected over 14 years for early pure-strain egg production. Differences among progeny from selected sires and dams, selected sires only, selected dams only, unselected sires and dams and the parental generation were equated to expected GA, GEP and M responses for each trait. Total response was 3.3% for early egg number, 3.7% for total egg number, 0.5% for egg weight, 3.8% for early egg mass and 4.2% for total egg mass. Among progeny that survived the test period and were judged to be normal, total response was 2.6% for total number of eggs, 3.0% for early egg mass and 3.1% for total egg mass. The percentage of T attributed to GA was 9% for early egg number, 24% for total egg number, 43% for early egg mass and 47% for total egg mass; but 52% for total egg number, 98% for early egg mass and 71% for total egg mass of normal survivors. Temporary maternal selection responses (M) were (1) positive for number of eggs and egg masses, (2) greater for all progeny than for normal survivors, and (3) increased with progeny age. The results suggest that M was caused by reduced egg-transmitted disease. Epistatic selection response was positive for earlier sexual maturity and for number of eggs, but negative for egg weight and thus was small for egg masses. Temporary epistatic and maternal responses can explain overestimation of additive genetic response from offspring-parent regression or from replicated single-generation selection and apparent superiority of mass selection over family or combined selection.

scholarly journals Selection for social genetic effects in purebreds increases growth in crossbreds

2021 ◽  
Vol 53 (1) ◽  
Author(s):  
Birgitte Ask ◽  
Lizette Vestergaard Pedersen ◽  
Ole Fredslund Christensen ◽  
Hanne Marie Nielsen ◽  
Simon P. Turner ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Genetic Correlation ◽  
Genetic Variance ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Genetic Effects ◽  
Group Variation ◽  
Selection For ◽  
Crossbred Pigs ◽  
Positive Effect

Abstract Background Average daily gain (ADG) in pigs is affected by both direct and social genetic effects (SGE). However, selection for SGE in purebreds has not conclusively been shown to improve ADG in crossbreds, and it is unknown whether SGE in purebreds are equal to those in crossbreds. Moreover, SGE may reflect dominance related behaviour, which is affected by the variation in body weight within a group. Therefore, we hypothesized that (a) there is a positive effect of parent average SGE estimated in purebred pigs on phenotypic ADG in crossbred offspring, and (b) there is an interaction between SGE on ADG and standard deviation in starting weight of pigs within the group. We also hypothesized that (c) social genetic variance for ADG exists in crossbred pigs, and (d) there is a favourable genetic correlation between SGE on ADG in purebred and crossbred pigs. Results We found a statistically significant interaction between the standard deviation in starting weight and SGE within groups, and conditioning on the mean standard deviation in starting weight, we found a favourable regression coefficient (0.37 ± 0.21) of ADG in crossbreds on SGE in purebreds. Variances for SGE were small in both Landrace (L) and Yorkshire (Y), and higher for SGE in both the dam and sire component of crossbred YL. The genetic correlations between SGE in purebreds and the dam or sire component of SGE in crossbreds were also favourable (0.52 ± 0.48 and 0.34 ± 0.42, respectively), although not significantly different from 0. Conclusions We confirmed that there is a positive effect of SGE estimated using purebred information on phenotypic ADG in crossbreds, and that the largest effect is achieved when the within-group variation in starting weight is small. Our results indicate that social genetic variance in crossbreds exists and that there is a favourable genetic correlation between social genetic effects in purebreds and crossbreds. Collectively, our results indicate that selection for SGE on ADG in purebreds in a nucleus farm environment with little competition for resources can improve ADG in crossbreds in a commercial environment.

scholarly journals Genetic parameters for egg production and egg weight of laying hens housed in single and group cages

2002 ◽  
Vol 45 (5) ◽  
pp. 501-508 ◽  
Author(s):  
V. Nurgiartiningsih ◽  
N. Mielenz ◽  
R. Preisinger ◽  
M. Schmutz ◽  
L. Schüler
Keyword(s):  
Variance Components ◽  
Egg Production ◽  
Genetic Parameters ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Multiple Trait ◽  
Group Cage ◽  
Egg Weight ◽  
Single Cage ◽  
Highly Correlated

Abstract. The present study was conducted to estimate the heritability and genetic correlation of monthly egg production and egg weight of 2 lines White Leghorn hens in single and group cages. A total of 2289 records (line A) and 2596 records (line D) from single cages, 518 and 541 records (for line A and D, respectively) from group cages, were analysed. (Co) variance components of single cage data were analysed using the programme VCE4 applying the REML method and a multiple trait animal model. An EM-algorithm was used to obtain (co) variance components for group cage data. Genetic correlations between single and group cages were analysed using the programme VCE4 based on sire model. Heritability estimates for monthly egg production in single cages ranged from 0.08 to 0.44 (line A); 0.04 to 0.43 (line D) and those for group cages were 0.02 to 0.42 (line A); 0.02 to 0.19 (line D). Egg weight was highly heritable for single and group cages (heritability = 0.25 to 0.54). The genetic correlations between monthly and cumulative egg production were 0.25 to 0.95 (line A); 0.26 to 0.86 (line D) for single cage and 0.24 to 0.84 (line A); 0.26 to 0.96 (line D) for group cage. Cumulative egg production in single cage were highly correlated with those of group cages (0.89 and 0.63, respectively for line A and line D). Single cage records gave higher estimates of genetic parameter than group records. However, the trend of estimates is almost the same. High genetic correlations were found between single- and group cages in most of the production periods.

Genetic Evaluation of Egg Production and Egg Quality Attributes in Japanese Quails through Partial Periods

2020 ◽  
Author(s):  
M. Monika ◽  
J.J. Rokadae ◽  
R. Narayan ◽  
Med Ram Verma ◽  
Snehasmita Panda ◽  
...  
Keyword(s):  
Japanese Quail ◽  
Egg Production ◽  
Egg Quality ◽  
Genetic Correlations ◽  
Production Performance ◽  
Experimental Population ◽  
Quality Traits ◽  
Egg Weight ◽  
Japanese Quails ◽  
Egg Number

Background: Egg production efficiency is typically measured through age and body weight at sexual maturity, egg number and egg weight during certain production periods. Increased egg weight and number of eggs are the primary purpose of the laying bird breeding programmes. Partial period analysis enhances selection process as the variations occurring throughout the bird’s productive life are identified and helps in the selection decisions. The current study aimed to study the genetic parameters such as heritability, phenotypic and genetic correlations to improve egg production performance and egg quality traits in Japanese quail reared at the Central Avian Research Institute (CARI).Methods: In present investigation, data recording was carried out from the Japanese quail population at experimental quail farm, CARI during 2019-2020. The individual mating was conducted between 180 sires and 180 dams of three varieties of Japanese quails were randomly selected from the base populations to develop first generation of experimental population. The hatched chicks were wing banded and the pedigree details recorded. For economic traits such as egg production and egg quality estimation, 40 sires and 40 dams were selected and parameters were evaluated. Result: In this present investigation, egg number from 10-16th week of age exhibited moderate to high heritable values. Egg weight was estimated moderate heritability traits. In egg quality traits, all values were moderate to high heritable values except yolk density in all the three varieties. 

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