The estimation of variance components for prolificacy and growth traits of Sakız sheep

Ceyhan, Ayhan; Sezenler, Tamer; Erdoğan, İsmail

doi:10.1016/j.livsci.2008.07.030

Cited by 22 publications

(17 citation statements)

References 18 publications

(48 reference statements)

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“…The birth type had effect on daily gain only in German Mutton Merino. The lack of influence of birth type on this trait in other breeds is not in agreement with the finding of others (Mavrogenis, 1988;Ceyhan et al, 2008). One explanation for the phenomenon is the compensatory growth during the fattening period.…”

Section: The Significance Of Factorscontrasting

confidence: 65%

Genetic Parameters for Growth Traits of the Hungarian Merino and Meat Sheep Breeds in Hungary

Kolmosi¹

2008

Appl Ecol Env Res

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Section: The Significance Of Factorscontrasting

confidence: 65%

Genetic Parameters for Growth Traits of the Hungarian Merino and Meat Sheep Breeds in Hungary

Kolmosi¹

2008

Appl Ecol Env Res

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“…Therefore, the effect of environmental (fixed) factors allocates a majority of the observed variation in these traits to itself. The results are consistent with the findings of Ekiz, Ozcan, Yilmaz, and Ceyhan (2005), Rashidi, Mokhtari, Safi Jahanshahi, and Mohammad Abadi (2008), Ceyhan, Sezenler, and Erdogan (2009), and Mohammadi, Moradi-Sharbabak, and Moradi-Sharbabak (2012). Various climatic, nutritional and management conditions in different years cause changes and fluctuations in livestock's production and reproduction performance.…”

Section: Resultssupporting

confidence: 91%

<b>Estimates of genetic and phenotypic parameters for reproductive traits in Iranian native Kordi sheep

Saghi

Shahdadi

2017

Acta Sci. Anim. Sci.

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ABSTRACT. The data set for estimation of genetic and phenotypic parameters of reproductive traits in Kordi sheep were collected from 1996 to 2013. The reproductive traits included age at first lambing (AFL), number of lambs born (NLB/EL) and weaned (NLW/EL) per ewe in each lambing, total weight of lambs born (TWLB/EL) and weaned (TWLW/EL) per ewe in each lambing, total number of lambs born (TNLB) and weaned (TNLW) per ewe, total weight of lambs born (TWLB) and weaned (TWLW) per ewe. The genetic parameters were estimated through restricted maximum likelihood method using WOMBAT. The effects of environmental factors (year of lambing, type of birth, maternal age at lambing) on all reproductive traits were significant (p < 0.01). Direct heritability, maternal heritability and the ratio of maternal permanent environmental variance to phenotypic variance for reproductive traits were estimated in the range from 0.07 to 0.18, 0.03 to 0.08 and 0.01 to 0.03, respectively. Genetic and phenotypic correlations between reproductive traits were estimated to be positive and within the range of 0.09 to 0.96 and 0.02 to 0.29, respectively. The results suggest that selection based on number of lambs born per ewe can be more effective than other traits in improving reproductive performance in Kordi ewes.Keywords: heritability, direct and maternal effect, genetic and phenotypic correlation, animal models.Estimativas de parâmetros genéticos e fenotípicos para características reprodutivas em ovinos Kordi nativos do Irã RESUMO. O conjunto de dados para a estimativa de parâmetros genéticos e fenotípicos de características reprodutivas em ovinos Kordi foi coletado de 1996 a 2013. As características reprodutivas incluíram idade ao primeiro parto, número de cordeiros nascidos e desmamados por ovelha em cada parição, peso total de cordeiros nascidos e desmamados por ovelha em cada parição, número total de cordeiros nascidos e desmamados por ovelha, peso total de cordeiros nascidos e desmamados por ovelha. Os parâmetros genéticos foram estimados pelo método de máxima verossimilhança restrita usando WOMBAT. Os efeitos dos fatores ambientais (ano de parto, tipo de nascimento, idade materna de parição) em todas as características reprodutivas foram significativos (p < 0,01). A herdabilidade direta, a herdabilidade materna e a razão entre variância ambiental permanente materna e variância fenotípica para características reprodutivas foram estimadas na faixa de 0,07 a 0,18; de 0,03 a 0,08 e de 0,01 a 0,03, respectivamente. As correlações genéticas e fenotípicas entre as características reprodutivas foram estimadas como sendo positivas e na faixa de 0,09 a 0,96 e de 0,02 a 0,29, respectivamente. Os resultados sugerem que a seleção baseada no número de cordeiros nascidos por ovelha pode ser mais eficaz do que outras características para melhorar o desempenho reprodutivo em ovelhas Kordi.Palavras-chave: hereditariedade, efeito direto e materno, correlação genética e fenotípica, modelos animais.

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“…Differences in maternal effects and maternal behaviour of ewe at different ages are the reasons for the significant effects of dam age on reproductive traits. Significant effects of dam age on reproductive traits of sheep have been reported in literature (Ceyhan et al 2009;Rashidi et al 2011;Mohammadi et al 2012;Amou Posht-e-Masari et al 2013;Mohammadabadi and Sattayimokhtari 2013). LSB = litter size at birth, LSW = litter size at weaning, LMWLB = litter mean weight per lamb born, LMWLW = litter mean weight per lamb weaned, TLWB = total litter weight at birth, TLWW = total litter weight at weaning *significant at P < 0.05, **significant at P < 0.01, ns = non-significant (P > 0.05) a-c different letters within the same column indicate significant differences doi: 10.17221/8242-CJAS Variance components and genetic parameters.…”

Section: Resultsmentioning

confidence: 99%

Estimation of genetic parameters for reproductive traits in Mehraban sheep

Yavarifard¹,

Hossein-Zadeh²,

Shadparvar³

2015

Czech J. Anim. Sci.

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Genetic parameters for basic and composite reproductive traits in Mehraban sheep were estimated. Data included 10 257 records on reproductive performances of 5813 lambs from 69 sires and 603 dams which were collected from 1994 to 2011 in the Mehraban breeding station in Hamedan province, western Iran. Studied traits were litter size at birth (LSB), litter size at weaning (LSW), litter mean weight per lamb born (LMWLB), litter mean weight per lamb weaned (LMWLW), total litter weight at birth (TLWB), and total litter weight at weaning (TLWW). Test of significance to include fixed effects in the statistical model was performed using the GLM procedure of SAS. Genetic parameters were estimated with univariate and bivariate repeatability animal models using WOMBAT program. Direct heritability estimates were 0.16, 0.14, 0.03, 0.16, 0.06, and 0.18 for LSB, LSW, LMWLB, LMWLW, TLWB, and TLWW, respectively, and corresponding repeatabilities were 0.02, 0.01, 0.73, 0.41, 0.27, and 0.03. The estimate for animal-dependent permanent environmental variance ranged from 0.01 ± 0.04 for LMWLW to 0.23 ± 0.04 for LSB. Genetic correlation estimates between traits ranged from −0.98 for LSB-LMWLW to 0.99 for LSB-TLWB. Phenotypic and environmental correlations were generally lower than genetic correlations. Phenotypic correlations ranged from −0.50 for LSB-LMWLB to 0.85 for LMWLW-TLWW. Environmental correlations ranged from −0.45 for LSB-LMWLB to 0.87 for LMWLW-TLWW. The results suggested that indirect selection based on TLWW could improve the reproductive performance in Mehraban ewes more effectively than if based on the other traits.

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The estimation of variance components for prolificacy and growth traits of Sakız sheep

Cited by 22 publications

References 18 publications

Genetic Parameters for Growth Traits of the Hungarian Merino and Meat Sheep Breeds in Hungary

Genetic Parameters for Growth Traits of the Hungarian Merino and Meat Sheep Breeds in Hungary

<b>Estimates of genetic and phenotypic parameters for reproductive traits in Iranian native Kordi sheep

Estimation of genetic parameters for reproductive traits in Mehraban sheep

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