scholarly journals Selection of a suitable definition of environment for the estimation of genotype × environment interaction in the weaning weight of beef cattle

2008 ◽  
Vol 53 (No. 10) ◽  
pp. 407-417 ◽  
Author(s):  
L. Vostrý ◽  
J. Přibyl ◽  
V. Jakubec ◽  
Z. Veselá ◽  
I. Majzlík
Keyword(s):  
Beef Cattle ◽  
Evaluation Model ◽  
Economic Value ◽  
Information Criterion ◽  
Ratio Test ◽  
Residual Variance ◽  
Environment Interaction ◽  
Weaning Weight ◽  
Genotype Environment Interaction ◽  
And Performance

Genotype by environment interactions for weaning weight in beef cattle were tested using several definitions of environments. Four breeds of beef cattle (Hereford, Aberdeen Angus, Beef Simmental, and Charolais) were represented. The environments were defined according to five criteria: altitude, production areas, economic value of the land, less favourable areas, and performance levels of a breed within herds. Ten mixed models were compared including the effects of direct and maternal genetics, herd-year-season, maternal permanent environmental, breed, environment, genotype × environment interaction, sex of calf, and age of dam. The suitability of the models was tested by Akaike’s Information Criterion, likelihood ratio test, and magnitude of the residual variance. The most suitable definitions of environment were less favoured areas and herd levels of performance. Estimates of direct heritability ranged from 0.07 to 0.19. Genotype × environment interactions should be included in a genetic evaluation model for interbreed comparisons of beef cattle in the Czech Republic.

scholarly journals Genotype-environment interaction, genetic trends, and performance dissimilarity of Nellore herds raised in three different environmental gradients

2018 ◽  
Vol 39 (1) ◽  
pp. 349
Author(s):  
Julio Cesar de Souza ◽  
Fabio Rafael Leão Fialho ◽  
Marcos Paulo Gonçalves Rezende ◽  
Carlos Henrique Cavallari Machado ◽  
Mariana Pereira Alencar ◽  
...  
Keyword(s):  
Weight Gain ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Environmental Gradients ◽  
Superior Performance ◽  
Environment Interaction ◽  
Genotype Environment Interaction ◽  
And Performance ◽  
Main Components ◽  
Genetic Trends

The objectives of this work were to evaluate the genotype-environment interaction, and estimate genetic parameters, genetic trends, and performance dissimilarity-weight gain from birth to weaning (WGBW), adjusted weight to 205 days (W205), weight gain from weaning to 18 months of age (WG18), and adjusted weight to 550 days (W550)-in Nellore animals born between 1986 and 2012, and raised in pasture-based system in three different environmental gradients in Brazil. Data of 62,001 animals-11,729 raised in the Alto Taquari/Bolsão region (ATBR), 21,143 raised in the Campo Grande/Dourados region (CGDR) and 29,129 raised in the western São Paulo/Paraná region (SPPR) in Brazil-were used. The contemporary groups were defined by sex, location, and birth year and season, with at least nine individuals, two different environments, and breeding bulls with at least five progenies. The statistical model contained the direct additive and residual genetic effects (random effects), and environmental and contemporary group effects (fixed effects). Genetic parameters, genotype-environment interaction and genetic trends were estimates using animal model (uni- and/or bi- traits). The level of similarity between regions was evaluated using principal components. The animals raised in the CGDR had superior performance regarding the traits evaluated. The direct heritability estimates ranged from 0.39 to 0.44 (WGBW), 0.41 to 0.45 (W205), 0.42 to 0.55 (WG18) and 0.60 to 0.62 (W550). The maternal heritability of the traits ranged from 0.20 (WGBW), 0.12 to 0.18 (W205), 0.00 to 0.06 (WG18) and 0.02 to 0.22 (W550). According to the Spearman correlation, the ranking of the breeding bulls in the regions evaluated were different. The mean of Euclidean distance indicated low similarity between ATBR and CGDR (43.20), and ATBR and SPPR (29.24). CGDR and SPPR presented similarity of 17.84. The breed values increased over the years in the traits evaluated. The cumulative variance percentage of the first two main components explained 99.99% variation among the regions, and the weight gains of the animals were the most important to differentiate the regions. A genotype-environment interaction was found for the traits evaluated, thus, the breeding bull selected with superior genetic merit for one region might not be the best for others.

Genotype×environment interaction for weaning weight in Nellore cattle using reaction norm analysis

2015 ◽  
Vol 176 ◽  
pp. 40-46 ◽  
Author(s):  
S. Ribeiro ◽  
J.P. Eler ◽  
V.B. Pedrosa ◽  
G.J.M. Rosa ◽  
J.B.S. Ferraz ◽  
...  
Keyword(s):  
Reaction Norm ◽  
Environment Interaction ◽  
Weaning Weight ◽  
Genotype Environment Interaction ◽  
Nellore Cattle

scholarly journals Models for multi-environment yield trials with fixed and random block effects and homogeneous and heterogeneous residual variances.

1969 ◽  
Vol 91 (3-4) ◽  
pp. 117-131
Author(s):  
Fernando Casanoves ◽  
Raúl Macchiavelli ◽  
Mónica Balzarini
Keyword(s):  
Analysis Of Variance ◽  
Block Design ◽  
Breeding Program ◽  
Residual Variance ◽  
Environment Interaction ◽  
Breeding Programs ◽  
Heterogeneous Variances ◽  
Genotype Environment Interaction ◽  
Random Block ◽  
Residual Variances

Multi-Environment Trials (METs) are used to make recommendations about genotypes at many stages of plant breeding programs. Because of the genotype-environment interaction, METs are usually conducted in various environments (locations and/or years), using designs which involve several repetitions (plots) for each genotype at each environment. The stratification or blocking of plots within each environment enables one to consider part of the variability due to differences between plots. The objective of this study was to see how frequently the problem of heterogeneous variances across environments appears in Peanut Breeding Program METs, and to evaluate the effects of diverse spatial modeling strategies on the comparison of genotype means in each environment. A series of 18 METs in a peanut breeding program with randomized complete block design in each environment were simultaneously adjusted by using 1) classic analysis of variance models (fixed and random block effects); 2) mixed models adjusted with homogenous and heterogeneous residual variances to take into account that experiments conducted in different environments may vary in precision (residual variances). The results suggest that the analysis of variance models with a block design and heteroscedastic errors between locations are more appropriate than their homogeneous residual variance versions.

scholarly journals Multiattribute Response of Maize Genotypes Tested in Different Coastal Regions of Brazil

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
Lúcio Borges de Araújo ◽  
Mario Varela Nualles ◽  
Mirian Fernandes Carvalho Araújo ◽  
Carlos Tadeu dos Santos Dias
Keyword(s):  
Principal Components ◽  
Environment Interaction ◽  
Coastal Regions ◽  
Multivariate Response ◽  
Genotype Environment Interaction ◽  
Maize Genotypes ◽  
The Mean ◽  
Components Analysis ◽  
And Performance ◽  
Main Effects

This work applies the three mode principal components analysis to analyze simultaneously the multiple attributes; to fit of models with additive main effects and multiplicative interaction effects (AMMI models) and the regressions models on sites (SREG models); to evaluate, respectively, the multivariate response of the genotype × environment interaction and the mean response of 36 genotypes of corn tested in 4 locations in Brazil. The results were presented by joint plots to identify the best genotypes for their adaptability and performance in the set of attributes.

scholarly journals Phenotypic and Quality Traits of Chickpea Genotypes under Rainfed Conditions in South Italy

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 962
Author(s):  
Mohamed Houssemeddine Sellami ◽  
Antonella Lavini ◽  
Cataldo Pulvento
Keyword(s):  
Seed Yield ◽  
Seed Quality ◽  
Ratio Test ◽  
Environment Interaction ◽  
South Italy ◽  
Legume Crop ◽  
Genotype Environment Interaction ◽  
The Stability ◽  
Total Seed

Chickpea (Cicer arietinum L.) is an important cool-season food legume crop that is mainly cultivated as a rainfed crop. This study was conducted in Italy between 2017 and 2019 to evaluate the stability of seed yield (SY), biomass (AGB) and 1000 seed weight (THS), and to assess the seed quality of 12 kabuli chickpea accessions under field conditions. The likelihood-ratio test revealed significant effects of genotype only for the SY and THS. The environment and genotype × environment interaction (GEI) effects were highly significant for all variables. We found that the environment (year) and GEI explain 55.72% and 20.87% of the total seed yield variation, respectively. Most chickpea accessions showed sensitivity to frost conditions in the third growing season. No relationship was observed between the yield and the protein content in Kabuli chickpea. Among the accessions, Ares and Reale showed the best performance under all environmental conditions, and the Reale was the most stable chickpea.

scholarly journals Genetic parameters for growth of young beef bulls

2012 ◽  
Vol 55 (3) ◽  
pp. 245-254
Author(s):  
L. Vostrý ◽  
Z. Veselá ◽  
J. Přibyl
Keyword(s):  
Fixed Effects ◽  
Genetic Effect ◽  
Information Criterion ◽  
Ratio Test ◽  
Residual Variance ◽  
Multiple Trait ◽  
Environment Effect ◽  
Body Weights ◽  
Direct Genetic Effect ◽  
Maternal Heritability

Abstract. The average daily gains of young bulls on test stations (ADGT) were analysed for the most frequent breeds of beef cattle in the Czech Republic using a multiple-trait animal model. Body weights at birth (W0), at 120 days of age (W120) and at weaning at 210 days (WW) were considered in this model as pre-weaning growth. The tested models comprised some of the random effects: direct genetic effect, maternal genetic effect, permanent animal environment effect, permanent maternal environment effect, and some of the fixed effects: dam’s age, sex, herd-year-season, linear and quadratic regression on age at the beginning of the test. For optimization of the models Akaike information criterion (AIC), residual variance and likelihood ratio test were used. Coefficients of direct and maternal heritability across breeds of about 0.25 for W0, about 0.17 for W120, about 0.17 for WW and about 0.29 for ADGT were estimated by all models. All criteria selected models including the permanent animal environment effect, which was the most important effect in the model.

91 Assessing Variability of Herd Sire Economic Value for Commercial Operations

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 46-47
Author(s):  
Logan Dodd ◽  
David Anderson ◽  
David G Riley ◽  
Barton Johnson ◽  
Andy D Herring
Keyword(s):  
Birth Weight ◽  
Mixed Model ◽  
Economic Value ◽  
Birth Date ◽  
Weight Class ◽  
Weaning Weight ◽  
Calf Performance ◽  
Breeding Groups ◽  
And Performance ◽  
Breeding Seasons

Abstract Number of calves (n = 596) and weaning calf value (n = 574) from natural service, multi-sire breeding groups were evaluated in a crossbred research herd. Sires and dams that were F1 crosses of Angus (A) and Nellore (N) were mated annually during 60 to 90-day breeding seasons to produce spring-born calves in 2009–2015. Numbers of sires used annually varied from 5 to 9; numbers of females exposed per bull ranged from 14 to 22 across years. Bulls were pastured together throughout the year as well as breeding seasons. Sires were identified based on calf DNA genotyping. Calf number, birth date, birth weight, weaning weight, and economic value were determined per bull annually. Calf value was based on weaning weight and reported prices for respective weaning dates. Calf prices were calculated separately for steers and heifers relative to 22.7 kg (50 lb) increments for corresponding weight class and year. Mixed model analyses were conducted that included fixed categorical effects of calf birth year, type of F1 sire (A-sired vs. N-sired), sire nested within type, calf sex, and the interaction of F1 sire type with calf sex. Covariates of Julian birth date and calf weaning age were included for birth weight and weaning weight, respectively. Large differences in calf numbers and performance (P < 0.05) were observed. Weaned calves produced annually per sire ranged from 0 to 48. Average annual calf performance per sire ranged from 28.4 to 50.8 kg for birth weight and 146.5 to 249.0 kg for weaning weight. Annual economic value per sire ranged from $0 to $30,870 when considering half of each calf’s value as attributed to the sire. Commercial producers should consider potential sire variability for calf numbers, birth date distribution, and ratio of female-to-male calves in combination with calf performance for economic assessments.

scholarly journals Genotype × country interaction for weaning weight in the Angus populations of Brazil and Uruguay

2011 ◽  
Vol 40 (3) ◽  
pp. 568-574 ◽  
Author(s):  
Ana Carolina Espasandin ◽  
Jorge Ignacio Urioste ◽  
Leonardo Talavera Campos ◽  
Maurício Mello de Alencar
Keyword(s):  
Fixed Effects ◽  
Environment Interaction ◽  
Month Of Birth ◽  
Weaning Weight ◽  
Additive Genetic Correlation ◽  
Genotype Environment Interaction ◽  
The One ◽  
Genetic Evaluations ◽  
Moderate Magnitude ◽  
Country Effect

It was analyzed the existence of genotype × environment interaction for weaning weight in populations of Angus from Brazil and Uruguay by using records of 73,205 animals (10,257 from Uruguay and 62,948 from Brazil) belonging to 33 and 161 farms and 13 and 34 regions in Uruguay and Brazil, respectively. It was used the one- and two-trait animal model analyses considering weight at weaning of each country as different characters. Coefficients of direct and maternal additive-genetic correlation estimated by two statistical models (including or not bull × country effect) Models included the fixed effects of contemporary group (herd-year and month of birth), sex of the calf, the covariates age of dam at calving (years) and age of calf at weaning (days), and the random effects genetic-additive maternal and direct, maternal permanent environment and residual. Herdabilidades (of direct effect) were similar in both countries and with moderate magnitude (0.35 and 0.15, respectively). Coeficients of correlation among maternal and direct genetic effects between Brazil and Uruguay were 0.77 and 0.13, respectively, and comparison among models (with and without bull × country effect) showed significant differences. Correlations among classifications (ranking of genetic values) of bulls with progenie in both countries ranged from 0.35 to 0.41 for estimations in one- and two-trait models, respectively. The results suggest the existence of genotype × environment interaction for weight at weaning of Angus populations between Brazil and Uruguay. There is a need of considering interaction in further international genetic evaluations of the breed.

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