scholarly journals Analysis of (co) variance components and estimation of breeding value of growth and production traits in Dahlem Red chicken using pedigree relationship in an animal model

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247779
Author(s):  
U. Rajkumar ◽  
L. Leslie Leo Prince ◽  
K. S. Rajaravindra ◽  
S. Haunshi ◽  
M. Niranjan ◽  
...  
Keyword(s):  
Animal Model ◽  
Maternal Effects ◽  
Variance Components ◽  
Egg Production ◽  
Genetic Correlations ◽  
The Body ◽  
Breeding Value ◽  
Egg Mass ◽  
Residual Variance ◽  
Production Traits

Variance and covariance components of growth and production traits were analyzed employing REML animal model to assess the Dahlem Red (PD-3) chicken population for direct additive genetic, maternal effects and to estimate the estimated breeding value (EBV), genetic parameters, genetic trends and rate of inbreeding (ΔF) utilizing seven generation’s data. The generation and hatch had significant (P≤0.01) effect on the body weight at 0 day (BW0), 2 (BW2), 4 (BW4) and 6 weeks (BW6) and shank length at six weeks of age (SL6). The average least squares means (LSM) for BW6 and SL6 were 273.93±0.62 g and 53.97±0.05 mm, respectively. All the production traits were significantly (P≤0.01) influenced by generation and hatch. The average LSM for age at sexual maturity (ASM), egg production up to 40 weeks (EP40) and egg mass up to 40 weeks (EM40) were 168.82±0.25 d, 72.60±0.41 eggs and 4.21±0.07 kg, respectively. Model 5 with additive direct, maternal genetic, maternal permanent environmental and residual variance components was the best for BW0, BW2 and BW4 based on the AIC values obtained in WOMBAT. Model 4 was the best model for BW6, SL6, ASM, EP40 and EM40 with additive direct, maternal permanent environmental and residual variance components. Maternal effects were higher during early age, decreased with age, and remained present until 20 weeks of age. The heritability (h2) estimates were low to moderate in magnitude for all the growth traits and ranged from 0.02±0.03 to 0.19±0.03. The maternal heritability was high at hatch (0.35±0.06), decreased gradually until 4th week (0.02±0.01) and ceased afterwards. The heritabilities of EP40 (0.11±0.03) and EM40 (0.12±0.04) were low. The direct additive genetic correlations (ra) between BW2, BW4, BW6 and SL6 were high and positive (P≤ 0.05). The additive genetic and maternal permanent environmental correlation between EP40 and EM40 were high and positive (P≤ 0.05). The EBV of EM40 was significant (P≤ 0.05) with 0.48 kg/generation in PD-3 chicken at the end of the seventh generation. The EBV of EP40 showed an increasing trend with a genetic gain of 1.87 eggs per generation. The average inbreeding coefficient of the population was 0.019 and average ΔF was 0.007 over the last seven generations of selection. The EBV trends for primary and associated traits showed linear trends in the desired direction and negligible inbreeding.

Genetic analysis of docility score of Australian Angus and Limousin cattle

2018 ◽  
Vol 58 (2) ◽  
pp. 213 ◽  
Author(s):  
S. F. Walkom ◽  
M. G. Jeyaruban ◽  
B. Tier ◽  
D. J. Johnston
Keyword(s):  
Adverse Effect ◽  
Animal Model ◽  
Genetic Analysis ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Production Costs ◽  
Breeding Value ◽  
Maternal Behaviour ◽  
Production Traits ◽  
Subjective Score

The temperament of cattle is believed to affect the profitability of the herd through impacting production costs, meat quality, reproduction, maternal behaviour and the welfare of the animals and their handlers. As part of the national beef cattle genetic evaluation in Australia by BREEDPLAN, 50 935 Angus and 50 930 Limousin calves were scored by seedstock producers for temperament using docility score. Docility score is a subjective score of the animal’s response to being restrained and isolated within a crush, at weaning, and is scored on a scale from 1 to 5 with 1 representing the quiet and 5 the extremely nervous or anxious calves. Genetic parameters for docility score were estimated using a threshold animal model with four thresholds (five categories) from a Bayesian analysis carried out using Gibbs sampling in THRGIBBS1F90 with post-Gibbs analysis in POSTGIBBSF90. The heritability of docility score on the observed scale was 0.21 and 0.39 in Angus and Limousin, respectively. Since the release of the docility breeding value to the Australian Limousin population there has been a favourable trend within the national herd towards more docile cattle. Weak but favourable genetic correlations between docility score and the production traits indicates that docility score is largely independent of these traits and that selection to improve temperament can occur without having an adverse effect on growth, fat, muscle and reproduction.

Estimation of genetic parameters of growth and egg production traits by animal model in IWK layer strain

2019 ◽  
Author(s):  
P. Chandan ◽  
T.K. Bhattacharya ◽  
U. Rajkumar ◽  
L.L.L. Prince ◽  
R.N. Chatterjee
Keyword(s):  
Animal Model ◽  
Body Weight ◽  
Egg Production ◽  
Heritability Estimate ◽  
The Body ◽  
Production Traits ◽  
Economic Traits ◽  
Egg Weight ◽  
Egg Number ◽  
Highly Correlated

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.

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.

Correlated response to selection for some egg performance traits in egg line of Japanese quail

2016 ◽  
Vol 56 (5) ◽  
pp. 913 ◽  
Author(s):  
B. Y. F. Mahmoud ◽  
G. Abou Khadiga ◽  
E. A. El-Full
Keyword(s):  
Japanese Quail ◽  
Egg Production ◽  
Genetic Correlations ◽  
Production Performance ◽  
Egg Mass ◽  
Correlated Response ◽  
Selection Experiment ◽  
Production Traits ◽  
Response To Selection ◽  
Female Line

Estimation of correlated response to selection in female line of Japanese quail after a short-term selection experiment was conducted. The total number of 547 female (275 selected and 272 control) Japanese quail included in the selection experiment of selection depended on aggregate breeding values based on animal model Best Linear Unbiased Prediction. Correlated selection response estimates were favourable for all the studied traits and significant (–0.38, –9.89, –12.86, –16.64, –5.08 and –8.24) for first egg weight (FEW), age at the first 10 eggs (AGE10), age at first 30 eggs (AGE30), age at first 60 eggs (AGE60), days needed to produce the first 30 eggs (DN30) and the first 60 eggs (DN60), respectively. Estimates of heritability were moderate for egg mass for the first 10 eggs (EM10), the first 30 eggs (EM30), the first 60 eggs (EM60), AGE10 and AGE30 (0.17–0.30), but low for AGE60, DN30 and DN60 (0.01–0.10). Genetic correlations between the selection criteria traits (AFE, BWSM and DN10) and the studied egg production traits were positive and ranged from 0.25 to 0.97, 0.24 to 0.95 and 0.06 to 0.98 for AFE, BWSM and DN10, respectively, whereas phenotypic correlations ranged from 0.12 to 0.89, 0.01 to 0.34 and 0.06 to 0.87 for the same traits. The favourable genetic response obtained for egg traits could be an indicator for improving egg production performance in Japanese quail.

EFFICIENCY AND COMPARISON OF THE TEST-DAY MODEL AND BLUP METHOD MODIFICATIONS FOR ASSESSING BULLS BREEDING VALUE IN SIMMENTAL CATTLE BREED

2020 ◽  
Author(s):  
А.И. МАМОНТОВА ◽  
С.А. НИКИТИН ◽  
Е.Е. МЕЛЬНИКОВА ◽  
А.А. СЕРМЯГИН
Keyword(s):  
Animal Model ◽  
Milk Yield ◽  
Cattle Breed ◽  
Breeding Value ◽  
Am1 Method ◽  
Production Traits ◽  
Genetic Trend ◽  
Sire Model ◽  
The Russian Federation ◽  
Simmental Cattle

Целью проведенных исследований являлась отработка и адаптация применения методик BLUP AM (Animal Model — модель животного) и TDM (Test-Day Model — модель тестового дня) для прогнозирования племенной ценности быков-производителей и оценки селекционно-генетических параметров на популяции скота симментальской породы четырех регионов РФ. Проведен сравнительный анализ указанных методов с более ранним методом BLUP SM (Sire Model — модель отца). Рассчитана племенная ценность быков и коров симментальской породы по признакам молочной продуктивности: удой за 305 дней, выход молочного жира, выход молочного белка. Анализ полученных средних значений достоверности оценок быков-производителей, рассчитанных на основе сопоставляемых методов, свидетельствует, что достоверность для признака «удой за 305 дней» при переходе от метода SM1 к AM1 увеличивается на 2,4%, а при переходе от SM1 к TDM1 — на 7,8%. Даны варианты генетического тренда по удою с использованием различных уравнений моделей расчета племенной ценности. На основании полученных данных можно сделать вывод о том, что модель тестового дня позволяет не только повысить точность оценок быков, но и более рельефно выявить их ранги, а также несколько уменьшить срок получения достоверных оценок производителей по качеству потомства по продуктивным признакам. The purpose of this research was to develop and adapt the application of BLUP AM (Animal Model) and TDM (Test-Day Model) methods for predicting the sires breeding value and evaluating genetic parameters for Simmental cattle population in four regions of the Russian Federation. A comparative analysis of these methods with the earlier BLUP SM (Sire Model) method is performed. The breeding value for sires and cows of Simmental breed was calculated by milk production traits: milk yield for 305 days; milk fatyield; milk proteinyield. The sires reliability of average breeding value calculated by different methods reveal that milk yield for 305 days when switching from the SM1 to AM1 method increases by 2.4%, and when switching from SM1 to TDM1 — by 7.8%.The variants of the genetic trend for milk yield are given using various equations of BLUP and TDM. Based on the obtained data, it can be concluded that the Test-Day model allows increasing the accuracy of bull’s evaluation and also more clearly identifying their ranks, as well as slightly reducing the time for obtaining reliable estimates of bulls by offspring for production traits.

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

Alterations in plasma constituents, growth and egg production traits due to selection in three genotypes of Japanese quail

2018 ◽  
Vol 156 (1) ◽  
pp. 118-126 ◽  
Author(s):  
G. S. Farahat ◽  
B. Y. Mahmoud ◽  
E. M. El-Komy ◽  
E. A. El-Full
Keyword(s):  
Body Weight ◽  
Japanese Quail ◽  
Egg Production ◽  
Body Weight Gain ◽  
Egg Mass ◽  
Production Traits ◽  
Total Lipids ◽  
Laying Performance ◽  
Productive Traits ◽  
And Control

AbstractThe present investigation was carried out to estimate the effects of genotype and sex on growth and laying performance and assess the variations in plasma constituents in the tested genotypes and their relations with productive traits after four generations of selection. Data of growth and laying performance on 1440 females and males of Japanese quail were taken from the three quail genotypes: maternal (MG), long shank length (LSG28) and control (CG) genotypes. Genotype significantly affected all studied growth productive traits, favouring selected genotypes. The LSG28surpassed MG in total protein, albumin (Alb), globulin (Glob), triglycerides and Alb/Glob ratio and lowered both cholesterol and total lipids (TL). Sex significantly favoured females, which had higher body weight, longer shank length at 35 days of age and higher body weight gain during the period from 1 to 35 days of age. Females showed significantly higher concentrations of both Alb and TL than males. The MG exceeded LSG28in fertility and hatchability per cent. Correlations for both growth and productive traits with plasma constituents revealed inconsistent trends in either magnitude or direction. Four generations of selection resulted in substantial phenotypic improvements in most growth and productive traits, as well as plasma constituents studied in LSG28, and favoured MG in maturity, days needed to produce the first ten eggs, higher egg production per cent and heavier egg mass.

Genetic resistance to two Marek's disease viruses and its relationship to production traits in chickens

1992 ◽  
Vol 72 (2) ◽  
pp. 213-225 ◽  
Author(s):  
H. Ameli ◽  
J. S. Gavora ◽  
R. W. Fairfull ◽  
J. L. Spencer
Keyword(s):  
Egg Production ◽  
Genetic Correlations ◽  
Genetic Resistance ◽  
Total Mortality ◽  
Marek's Disease ◽  
Production Test ◽  
Production Traits ◽  
Marek’S Disease ◽  
Genetic Groups ◽  
Challenge Tests

Genetic variability of resistance to Marek's Disease (MD), and relationships between MD incidence and egg production traits were studied in 23 genetic groups of experimental and commercial meat and egg chickens. In the challenge tests, chickens were injected with either moderately virulent BC-1 MD virus (BC-1) or highly virulent RB-1B MD virus (RB-1B). In the 497-d egg-production test, sisters of challenged birds were vaccinated for MD on the day of hatch and there were no outbreaks of MD. Heritabilities for MD incidence, MD mortality, and total mortality in the challenge tests, based on data from three unselected control strains of Leghorns were generally low (0.06, 0.13 and 0.20) with BC-1. With RB-1B, the heritability estimates were significantly (P <.05) higher (0.62, 1.00 and 0.96). Intraclass correlations, based on variation between and within the genetic groups were also higher with RB-1B. In the test with BC-1 there were deaths from an early mortality syndrome (EMS) prior to development of MD. Losses from EMS in Leghorns were highest in 2 genetic groups most resistant to MD. Based on genetic group means, correlations between MD incidence and egg production and egg weight were high and negative. In contrast the correlations between MD incidence, age at first egg, total blood spots, and egg specific gravity tended to be positive. No consistent relationships were found with adult body weight. Key words: Marek's disease, genetic resistance, heritability, genetic correlations, production traits, chickens

scholarly journals Genetic parameters for test day milk yield of first lactation Holstein cows estimated by random regression using Legendre polynomials

2008 ◽  
Vol 37 (4) ◽  
pp. 602-608 ◽  
Author(s):  
Claudio Napolis Costa ◽  
Claudio Manoel Rodrigues de Melo ◽  
Irineu Umberto Packer ◽  
Ary Ferreira de Freitas ◽  
Nilson Milagres Teixeira ◽  
...  
Keyword(s):  
Variance Components ◽  
Legendre Polynomials ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Random Regression ◽  
Holstein Cows ◽  
Residual Variance ◽  
Environmental Variance ◽  
Environmental Correlations ◽  
Lp Estimates

Data comprising 263,390 test-day (TD) records of 32,448 first parity cows calving in 467 herds between 1991 and 2001 from the Brazilian Holstein Association were used to estimate genetic and permanent environmental variance components in a random regression animal model using Legendre polynomials (LP) of order three to five by REML. Residual variance was assumed to be constant in all or in some classes of lactation periods for each LP. Estimates of genetic and permanent environmental variances did not show any trend due to the increase in the LP order. Residual variance decreased as the order of LP increased when it was assumed constant, and it was highest at the beginning of lactation and relatively constant in mid lactation when assumed to vary between classes. The range for the estimates of heritability (0.27 - 0.42) was similar for all models and was higher in mid lactation. There were only slight differences between the models in both genetic and permanent environmental correlations. Genetic correlations decreased for near unity between adjacent days to values as low as 0.24 between early and late lactation. A five parameter LP to model both genetic and permanent environmental effects and assuming a homogeneous residual variance would be a parsimonious option to fit TD yields of Holstein cows in Brazil.

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