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 | Acesso ao texto completo restrito à biblioteca da Embrapa Caprinos e Ovinos. Para informações adicionais entre em contato com cnpc.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
01/08/1992 |
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Data da última atualização: |
08/05/2023 |
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Autoria: |
YOUNG, S. S. Y.; TURNER, H. N.; DOLLING, C. H. S. |
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Afiliação: |
HELEN NEWTON TURNER. |
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Título: |
Selection for fertility in Australian Merino sheep. |
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Ano de publicação: |
1963 |
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Fonte/Imprenta: |
Australian Journal of Agricultural Research, v. 14, n. 4, p. 460-482, 1963. |
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DOI: |
10.1071/AR9630460 |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: Phenotypic and genetic parameters for fertility in sheep, in terms of number of lambs born and number weaned, have been estimated in a flock of medium Peppin Merinos. Repeatability of fertility traits over all ages is low, but there is an age effect, the record at 3 years of age having a higher value than those at 2 or 4 years. The regression of subsequent performance on a difference of 1 lamb at the initial lambing was higher for the difference between 1 and 2 lambs than between 0 and 1 lamb, which indicated that selection for twins is likely to raise fertility in the current flock more rapidly than selection against barrenness. The estimate of heritability for 2 years of age was negligible for each fertility trait, but the estimates for the 3-year-old record were higher, the value for lambs born being over 0.3. Mass selection for number of lambs born at 3 years of age would thus be expected to lead to appreciable genetic progress, while there would be at least some progress in number of lambs weaned. Phenotypic and genetic correlations were also estimated between fertility at different ages and 10 sheep and wool traits measured at 15?16 months of age. Phenotypically, fertility is positively correlated with body weight and negatively with skin wrinkle score. Genetically, it is suggested from the estimates that fertility is positively correlated with body weight and staple length and negatively correlated with fibre diameter, clean scoured yield, and wrinkle score. No phenotypic or genetic correlation was found between greasy or clean wool weight and either measure of fertility. The application of the findings to breeding for higher fertility is discussed. In an appendix, a maximum likelihood method of estimating heritability for all-or-none traits in half-sib data is presented. MenosAbstract: Phenotypic and genetic parameters for fertility in sheep, in terms of number of lambs born and number weaned, have been estimated in a flock of medium Peppin Merinos. Repeatability of fertility traits over all ages is low, but there is an age effect, the record at 3 years of age having a higher value than those at 2 or 4 years. The regression of subsequent performance on a difference of 1 lamb at the initial lambing was higher for the difference between 1 and 2 lambs than between 0 and 1 lamb, which indicated that selection for twins is likely to raise fertility in the current flock more rapidly than selection against barrenness. The estimate of heritability for 2 years of age was negligible for each fertility trait, but the estimates for the 3-year-old record were higher, the value for lambs born being over 0.3. Mass selection for number of lambs born at 3 years of age would thus be expected to lead to appreciable genetic progress, while there would be at least some progress in number of lambs weaned. Phenotypic and genetic correlations were also estimated between fertility at different ages and 10 sheep and wool traits measured at 15?16 months of age. Phenotypically, fertility is positively correlated with body weight and negatively with skin wrinkle score. Genetically, it is suggested from the estimates that fertility is positively correlated with body weight and staple length and negatively correlated with fibre diameter, clean scoured yield, and wrinkle score.... Mostrar Tudo |
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Palavras-Chave: |
Genetic parameters; Melhoramento genético. |
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Thesagro: |
Genética Animal; Ovino; Seleção Genética. |
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Thesaurus Nal: |
Animal genetics; Body weight; Phenotypic correlation; Repeatability; Sheep. |
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Categoria do assunto: |
G Melhoramento Genético |
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Marc: |
LEADER 02613naa a2200277 a 4500
001 1523611
005 2023-05-08
008 1963 bl uuuu u00u1 u #d
024 7 $a10.1071/AR9630460$2DOI
100 1 $aYOUNG, S. S. Y.
245 $aSelection for fertility in Australian Merino sheep.$h[electronic resource]
260 $c1963
520 $aAbstract: Phenotypic and genetic parameters for fertility in sheep, in terms of number of lambs born and number weaned, have been estimated in a flock of medium Peppin Merinos. Repeatability of fertility traits over all ages is low, but there is an age effect, the record at 3 years of age having a higher value than those at 2 or 4 years. The regression of subsequent performance on a difference of 1 lamb at the initial lambing was higher for the difference between 1 and 2 lambs than between 0 and 1 lamb, which indicated that selection for twins is likely to raise fertility in the current flock more rapidly than selection against barrenness. The estimate of heritability for 2 years of age was negligible for each fertility trait, but the estimates for the 3-year-old record were higher, the value for lambs born being over 0.3. Mass selection for number of lambs born at 3 years of age would thus be expected to lead to appreciable genetic progress, while there would be at least some progress in number of lambs weaned. Phenotypic and genetic correlations were also estimated between fertility at different ages and 10 sheep and wool traits measured at 15?16 months of age. Phenotypically, fertility is positively correlated with body weight and negatively with skin wrinkle score. Genetically, it is suggested from the estimates that fertility is positively correlated with body weight and staple length and negatively correlated with fibre diameter, clean scoured yield, and wrinkle score. No phenotypic or genetic correlation was found between greasy or clean wool weight and either measure of fertility. The application of the findings to breeding for higher fertility is discussed. In an appendix, a maximum likelihood method of estimating heritability for all-or-none traits in half-sib data is presented.
650 $aAnimal genetics
650 $aBody weight
650 $aPhenotypic correlation
650 $aRepeatability
650 $aSheep
650 $aGenética Animal
650 $aOvino
650 $aSeleção Genética
653 $aGenetic parameters
653 $aMelhoramento genético
700 1 $aTURNER, H. N.
700 1 $aDOLLING, C. H. S.
773 $tAustralian Journal of Agricultural Research$gv. 14, n. 4, p. 460-482, 1963.
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| 1. |  | CONCEIÇÃO, R. R. P.; QUEIROZ, V. A. V.; MEDEIROS, E. P. de; ARAUJO, J. B. de; SILVA, D. D. da; MIGUEL, R. de A.; STOIANOF, M. A. de R.; SIMEONE, M. L. F. Determinação do teor de fumonisina em milho usando a tecnologia de imagem hiperespectral no infravermelho próximo (HSI-NIR) e métodos quimiométricos. In: WOKSHOP DE QUIMIOMETRIA, 11., 2020, Campina Grande, PB. Anais... Campina Grande: Universidade Estadual da Paraíba, 2020. p. 173.| Tipo: Resumo em Anais de Congresso |
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