Animal Model Genetic Evaluation of Type Traits for Five Dairy Cattle Breeds

Gengler, Nicolas; Wiggans, G.R.; Wright, J.R.

doi:10.3168/jds.s0022-0302(99)75359-2

Cited by 17 publications

(17 citation statements)

References 14 publications

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“…Current Genetic Model for Type Traits. The genetic evaluation model used for type traits is based on the one used for the genetic evaluation of non-Holstein breeds in the United States (Gengler et al, 1999(Gengler et al, , 2001a. This genetic evaluation method consists of 3 interdependent iterative systems that solve regular mixed model equations on a canonical scale, allowing the update of canonical traits to account for missing original traits.…”

Section: Modelsmentioning

confidence: 99%

Inbreeding Depression for Global and Partial Economic Indexes, Production, Type, and Functional Traits

Croquet

Mayeres

Gillon

et al. 2006

Journal of Dairy Science

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The objective of this research was to examine the effects of inbreeding in the population of Holstein cattle in the Walloon region of Belgium. The effects of inbreeding on the global economic index and its components were studied by using data from the genetic evaluations of February 2004 for production, somatic cell score (SCS), computed from somatic cell counts and type. Inbreeding coefficients for 956,516 animals were computed using a method that allows assigning an inbreeding coefficient to individuals without known parents. These coefficients were equal to the mean inbreeding coefficient of contemporary individuals with known parents. The significance of inbreeding effects on the different evaluated traits and on the different indexes were tested using a t-test comparing estimated standard errors and effects. The inbreeding effect was significantly different from zero for the vast majority of evaluated traits and for all of the indexes. Inbreeding had the greatest deleterious effects on production traits. Inbreeding decreased yield of milk, fat, and protein during a lactation by 19.68, 0.96, and 0.69 kg, respectively, per each 1% increase in inbreeding. The regression coefficient of SCS per 1% increase in inbreeding was +0.005 SCS units. The inbreeding depression was thus relatively low for SCS, but inbred animals had higher SCS than non-inbred animals, indicating that inbred animals would be slightly more sensitive to mastitis than non-inbred animals. Estimates of inbreeding effects on evaluated type traits per 1% increase were small. The most strongly affected type traits were chest width, rear leg, and overall development on a standardized scale. For several type traits, particularly traits linked to the udder, the estimates suggested a favorable effect of inbreeding. The global economic index was depressed by around 6.13 € of lifetime profit per 1% increase in inbreeding for the Holstein animals in the Walloon region of Belgium.

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Section: Modelsmentioning

confidence: 99%

Inbreeding Depression for Global and Partial Economic Indexes, Production, Type, and Functional Traits

Croquet

Mayeres

Gillon

et al. 2006

Journal of Dairy Science

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“…Tabela 4 -Classificação final (CLF) e características de classificação formato (FRM), característica leiteira (CLE), capacidade corporal (CCO), pernas e pés (PPE) e sistema mamário (SMA), segundo a idade da vaca a classificação (IVC) Gengler et al (1999), também com animais da raça Pardo-Suíça, observa-se que as estimativas destes autores são levemente superiores às verificadas neste trabalho, principalmente para as características lineares profundidade corporal, abertura de garupa e tamanho de tetas. Estimativas de herdabilidade de outros estudos, como os de , Misztal et al (1992) Esteves (1999), ambos com animais da raça Holandesa, as estimativas de herdabilidade foram superiores as encontradas neste trabalho com animais da raça Pardo-Suíça, demonstrando que as estimativas de herdabilidade das características de conformação podem variar em função do sistema de classificação utilizado e da raça avaliada, como mostram os resultados obtidos por Gengler et al (1999) avaliando cinco diferentes raças leiteiras (Pardo-Suíça; Jersey; Ayrshire; Guernsey; Milking Shorthorn).…”

Section: Fr=frame; Dc=dairy Character; Bc=body Capacity; Fl=feet and unclassified

“…Estimativas de herdabilidade de outros estudos, como os de , Misztal et al (1992) Esteves (1999), ambos com animais da raça Holandesa, as estimativas de herdabilidade foram superiores as encontradas neste trabalho com animais da raça Pardo-Suíça, demonstrando que as estimativas de herdabilidade das características de conformação podem variar em função do sistema de classificação utilizado e da raça avaliada, como mostram os resultados obtidos por Gengler et al (1999) avaliando cinco diferentes raças leiteiras (Pardo-Suíça; Jersey; Ayrshire; Guernsey; Milking Shorthorn).…”

Section: Fr=frame; Dc=dairy Character; Bc=body Capacity; Fl=feet and unclassified

“…Foram verificadas altas correlações gené-ticas entre a estatura e as características lineares de garupa (ângulo e abertura de garupa), a angulosidade e as características lineares de sistema mamário (com exceção do comprimento de tetas), indicando que a seleção para animais altos indiretamente resulta em animais angulosos, com garupa ampla e ligeiramente baixa, e sistema mamário bem conformado. Gengler et al (1999) verificaram resultados semelhantes com animais das raças Pardo-Suíça, Jersey e Guernsey.…”

Section: Milk Yieldunclassified

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Correlações genéticas e fenotípicas entre características de conformação e produção de leite em bovinos da raça Pardo-Suíça no Brasil

Rennó

Araújo²,

Pereira

et al. 2003

R. Bras. Zootec.

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RESUMO -Foram avaliados dados de classificação para tipo fornecidos pela Associação Brasileira de Criadores de Gado PardoSuíço com o objetivo de avaliar os efeitos de fatores não-genéticos, estimar a herdabilidade e as correlações genéticas e fenotípicas das características lineares de tipo, características de classificação e a classificação final, bem como avaliar as correlações das características de tipo com a produção de leite. Para o estudo dos fatores não-genéticos foi utilizado o método dos quadrados mínimos, utilizando-se o procedimento GLM do SAS, e, para a estimativa da herdabilidade e correlações genéticas e fenotípicas, foi utilizado um modelo animal. Os componentes de variância e (co)variância foram obtidos com o programa MTDFREML (Multiple Trait Derivative Free Restricted Maximum Likelihood), utilizando a metodologia de máxima verossimilhança restrita livre de derivadas. Os efeitos não-genéticos influenciaram a avaliação da maioria das características de tipo, devendo ser considerados nas avaliações de conformação de bovinos desta raça. As estimativas de herdabilidade obtidas sugerem a possibilidade de ganhos genéticos moderados advindos da seleção para características de tipo. Devido às altas correlações genéticas entre as características lineares de tipo, programas de melhoramento para características de conformação podem ser implementados sem a necessidade de inclusão de todas as características. As correlações genéticas observadas entre algumas características de tipo e a produção de leite sugerem a participação destas na formação de índices de seleção para animais desta raça. Palavras-chave: características de tipo, parâmetros genéticos, Pardo-Suíço Genetic and Phenotypic Correlations Among Type Traits and Milk Yield of Brown Swiss Cattle in BrazilABSTRACT -Data of type classification from Brown Swiss Cattle Breeder's Association of Brazil were used to evaluate non-genetic factors, heritability and genetic and phenotypic correlations of the linear type traits, classification traits and final score, as well as to evaluate correlations of type traits and milk yield. For the study of non-genetic factors was utilized the least square metolology using the GLM procedure of SAS, and, for estimate of heritability and genetic and phenotypic correlation was used an animal model. The REML metodology was used to obtain variance and covariance components to estimate heritability and genetic and phenotypic correlations. The non-genetic factors influenced most of the type traits and should be considered in the type evaluation of cattle of this breed. Heritability estimates suggest the possibility of moderate genetic gain for selection of type traits. Genetic correlations among some type traits were high, suggesting that some of them could be excluded from the used classification system. The genetic correlations between some type traits and milk yield suggest the participation of these in the elaboration of selection index of animals of this breed.

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“…A multitrait model has been used by the Animal Improvement Programs Laboratory, ARS, USDA (Beltsville, MD), to calculate genetic evaluations for linear type traits of all breeds except Holstein since February 1998 (Gengler et al, 1999). The Holstein Association USA (Brattleboro, VT) calculates the Holstein type evaluations.…”

Section: Introductionmentioning

confidence: 99%

Type Trait (Co)Variance Components for Five Dairy Breeds

Wiggans

Gengler²,

Wright

2004

Journal of Dairy Science

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ABSTRACT(Co)variance components were estimated for final score and 14 or 15 linear type traits for the Ayrshire, Brown Swiss, Guernsey, Jersey, and Milking Shorthorn breeds. Appraisals from 1995 or later were used. New estimates were calculated to accommodate changes in scoring of traits and because of a change from multiplicative to additive adjustment for age and lactation stage. The adjustment method was changed for better support of the adjustment for heterogeneous variance within iteration, which was implemented in 2002. The largest changes in heritability were an increase of 0.10 for rump angle for Milking Shorthorns and a decrease of 0.11 for udder depth for Jerseys. The new estimates of (co)variance components should provide improved accuracy of type evaluations, particularly for traits that have had variance changes over time.

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Animal Model Genetic Evaluation of Type Traits for Five Dairy Cattle Breeds

Cited by 17 publications

References 14 publications

Inbreeding Depression for Global and Partial Economic Indexes, Production, Type, and Functional Traits

Inbreeding Depression for Global and Partial Economic Indexes, Production, Type, and Functional Traits

Correlações genéticas e fenotípicas entre características de conformação e produção de leite em bovinos da raça Pardo-Suíça no Brasil

Type Trait (Co)Variance Components for Five Dairy Breeds

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