(Co)variance components and genetic parameters for growth traits in Arabi sheep using different animal models

Shokrollahi, Borhan; Baneh, Hasan

doi:10.4238/2012.february.8.5

Cited by 24 publications

(24 citation statements)

References 23 publications

(37 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Decreasing number of records with maturation of lambs was in agreement of El-Awady (2011), Shokrollahi and Baneh (2012) who worked on 2248, 3331 for BW, 2024, 2548 for WT3, and 1937, 2430 records for WT6 in Barki, and Arabi sheep, respectively. This declining in number of lambs was attributed to lamb culling, selling lambs at older ages, data sets, and mortality rate.…”

Section: Resultssupporting

confidence: 83%

“…Mohammadi et al (2013) Negative  am and r am are in consonance with the reports of María et al (1993) on BW of Romanov sheep; El-Awady (2011) on BW due to the reverse effect of ewes on the maternal ability of their females through offspring over nutrition; Shokrollahi and Baneh (2012) on growth traits in Arabi sheep. Negative association between direct and maternal genetic effect indicating high genetic antagonism between them which propose that these effects tend to amend for high or low weight in the correlated effect.…”

Section: Resultssupporting

confidence: 81%

“…heritability estimates, genetic correlation, and so on) as documented by Shokrollahi and Baneh (2012). Such estimates could be evaluated from an appropriate animal model which should be closer to biological one (Assan, 2013).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Impact of maternal components on fitting of animal models in genetic parameters estimation for body weight traits in Rahmani lambs

Radwan

Shalaby

Gabr

2018

IJAR

View full text Add to dashboard Cite

The present research was undertaken to determine the effect of application animal six models including or ignoring maternal genetic and/or maternal permanent environmental effects based on single and multi-trait animal model analyses and choose the most efficient method of selection to improve body weight traits in Rahmani lambs on genetic base. Current findings pointed to increase phenotypic variances of weight traits by increasing lamb's age. Maternal environmental effects shared approximately 13% (ranged from 11% to 20%) of the whole phenotypic variation for body weight traits in multi-trait analysis and thereafter declined significantly for all the traits especially in single-trait analysis. The results show the significance of including at least one maternal component with covariance between direct and maternal effect for genetic evaluation body weight traits and high direct heritability estimates denoted possibility to use weight traits as selection criteria due to their direct response to genetic improvement through direct selection method and their economic importance in mutton production.

show abstract

Section: Resultssupporting

confidence: 83%

Section: Resultssupporting

confidence: 81%

See 1 more Smart Citation

Impact of maternal components on fitting of animal models in genetic parameters estimation for body weight traits in Rahmani lambs

Radwan

Shalaby

Gabr

2018

IJAR

View full text Add to dashboard Cite

show abstract

“…In model 4, the estimate of direct-maternal genetic covariance ( am ) was positive (0.03) and the direct maternal genetic correlation (r am ) was 0.43, with corresponding small differences in likelihoods between models 3 and 4. Based on the logarithm of the likelihood function, fitting both genetic and environmental components of the dam (Model 5) Shokrollahi and Baneh (2012) for Arabi sheep (0.42).The low heritability estimates for birth weight in the present study can be explained by the poor nutritional level of ewes at the sheep-breeding station creating large environmental variation. In addition, high contribution of maternal effects in this trait may be another reason of this situation.…”

Section: Birth Weightmentioning

confidence: 98%

Genetic parameter estimates for growth traits in Iran-Black sheep

Kamjoo

Baneh

Yousefi

et al. 2013

Journal of Applied Animal Research

View full text Add to dashboard Cite

The present study was conducted to estimate variance components and genetic parameters for growth traits of Iran-Black sheep, maintained at the Abbasabad sheep breeding station, located in northeast of Mashhad, (Razavi Khorasan province of Iran) over a period of 24 years (1981 through 2004). Records of 4607 lambs descended from 155 rams, and 1227 ewes were used in the study. Traits included for the present study were birth weight (BW), weaning weight (WW), weight at 6 months (W6), weight at 9 months (W9), and yearling weight (YW). Analyses were carried out by restricted maximum likelihood (REML) fitting an animal model and ignoring or including maternal genetic or permanent environmental effects. Six different animal models were fitted for all traits. The most appropriate model was chosen after testing the improvement of the log-likelihood values. Heritability estimates for weight at birth; weaning; and 6, 9, and 12 months of age were 0.04, 0.14, 0.16, 0.19, and 0.18, respectively. Maternal heritability of body weight declined from 0.33 at birth to 0.04 at six months of age. The maternal permanent environmental component accounted for 6% to 15% to the total variance for all traits under study. The direct-maternal genetic correlation (r am ) was positive for all traits and ranged from 0.3690.27 for BW to 0.9990.98 for YW, but was never significant. The results showed that modest rates of genetic progress appear possible for all weights. Results also suggest that maternal additive effects were only important in early stages of growth, whereas a permanent environmental maternal effect existed at all ages up to 12 months of age, probably as a carry-over effect of maternal influences present at weaning. Direct genetic correlations (r a1,a2 ) between traits were positive and ranged from 0.82 (BW-WW) to 0.99 (W6-YW). The estimates of correlation between permanent environmental maternal effect among traits were close to those of r a1,a2 . Phenotypic and environmental correlations for all traits were generally lower than direct genetic correlations.

show abstract

“…Therefore, Zamani and Mohammadi (2008) and Shokrollahi and Baneh (2012) found a better fit for the model that considered the two genetic effects (direct and maternal) and the covariance between them. In turn, Aguirre, Mattos, Eler, Barreto Neto, and Ferraz (2016), observed that the best fit of the data was obtained with the model that considered, besides the direct maternal and maternal permanent environmental effects, also the covariance between the direct and maternal effects.…”

Section: Resultsmentioning

confidence: 99%

<b>Genetic components of birth weight of texel sheep reared in extensive system

Amarilho-Silveira

Dionello

Mendonça

et al. 2017

Acta Sci. Anim. Sci.

View full text Add to dashboard Cite

ABSTRACT. This study aimed to estimate the components of (co)variance, genetic and phenotypic parameters and trends for birth weight. We used 783 birth weight records, between 2012 to 2016, of Texel sheep reared in extensive system. The components of (co)variance and the genetic parameters were estimated using six different animal models, using the restricted maximum likelihood method (REML). The model that best fit the data was Model 3, with estimates of direct additive genetic variance of 0.004, maternal permanent environment variance of 0.164, heritability coefficient of 0.011 and phenotypic variation attributed to the maternal permanent environment of 0.394. For the genetic trend, we observed a genetic gain of 0.413% and for the phenotypic trend, a phenotypic gain of 0.159 kg, between 2012 and 2016 were found. Estimates of direct heritability and proportion of the phenotypic variance explained by the maternal permanent environment presented lower and higher values, respectively, in comparison to other studies. For trends, both genetic and phenotypic, there were gains in birth weight between 2012 and 2016.Keywords: maternal permanent environment, heritability, sheep breeding, direct additive variance.Componentes genéticos do peso de ovinos texel, ao nascimento, criados em sistema extensivo RESUMO. Este trabalho foi realizado para estimar os componentes de (co)variância, parâmetros e tendências genéticas e fenotípicas do peso de ovinos da raça Texel, ao nascimento. Foram utilizados 783 registros de peso ao nascimento, entre os anos de 2012 a 2016, de ovinos criados em sistema extensivo. Foram estimados os componentes de (co)variância e os parâmetros genéticos com seis diferentes modelos animais, utilizando o método da máxima verossimilhança restrita (REML -Restricted Maximum Likelihood). O modelo que melhor se ajustou aos dados foi o modelo 3, com estimativas de variância genética aditiva direta de 0,004, variância do ambiente permanente materno de 0,164, coeficiente de herdabilidade de 0,011 e variação fenotípica atribuída ao ambiente permanente materno de 0,394. Foram constatados para a tendência genética um ganho genético de 0,413% e um ganho fenotípico de 0,159 kg para a tendência fenotípica, entre os anos de 2012 a 2016. As estimativas de herdabilidade direta e da proporção da variância fenotípica explicada pelo ambiente permanente materno apresentaram valores inferiores e superiores, respectivamente, em comparação a outros estudos. Para as tendências, tanto genética, como fenotípica, houve ganho no peso ao nascimento, entre os anos de 2012 a 2016.Palavras-chave: ambiente permanente materno, herdabilidade, melhoramento genético ovino, variância aditiva direta.

show abstract

(Co)variance components and genetic parameters for growth traits in Arabi sheep using different animal models

Cited by 24 publications

References 23 publications

Impact of maternal components on fitting of animal models in genetic parameters estimation for body weight traits in Rahmani lambs

Impact of maternal components on fitting of animal models in genetic parameters estimation for body weight traits in Rahmani lambs

Genetic parameter estimates for growth traits in Iran-Black sheep

<b>Genetic components of birth weight of texel sheep reared in extensive system

Contact Info

Product

Resources

About