Estimated Direct and Correlated Response to Selection for Performance Traits in Closed Hereford Lines under Different Types of Environments

Cm, Bailey; Wr, Harvey; Je, Hunter; Cr, Torell

doi:10.2527/jas1971.333541x

Cited by 13 publications

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“…Feed costs represent a major economic input for beef cattle production. Individual cattle differ in their ability to efficiently utilize feed (Bailey et al, 1971;Garrett, 1971;Freeman, 1975). Selecting the most efficient animals may significantly lower production costs.…”

Section: Introductionmentioning

confidence: 99%

Genetic parameter estimation of postweaning gain, feed intake, and feed efficiency for Hereford and Angus bulls fed two different diets

Fan

Bailey

Shannon

1995

Journal of Animal Science

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Postweaning gain performance and individual feed intake on 271 Hereford and 263 Angus bulls were recorded during three 168-d test periods from 1984 to 1986. Each breed was composed of two lines and within each breed bulls were fed either a high-energy (HD) or a medium-energy (MD) diet. Energy intake was partitioned into energy for maintenance and growth based on predicted individual animal requirements. Estimates of heritability were obtained using Restricted Maximum Likelihood with an individual animal model including fixed effects of year, diet, and covariates of initial weight and backfat change by breed and with line effects for overall data. Bulls fed the HD grew faster and had higher metabolizable energy intake per day (MEI), residual feed consumption (RFC), and gross and net feed efficiency (FE and NFE) (P < .001) than those fed the MD. Estimates of heritability for Hereford and Angus bulls, respectively, were .46 and .16 for 200-d weaning weight (WWT), .16 and .43 for average daily gain (ADG), .19 and .31 for intake per day (MEI), .43 and .45 for yearling weight (YWT), .07 and .23 for RFC, .08 and .35 for FE, and .14 and .28 for NFE. Genetic and phenotypic correlations between MEI and ADG, MEI and YWT, ADG and YWT, ADG and FE, YWT and FE, and FE and NFE were moderately to highly positive for both breeds. Negative genetic and phenotypic correlations between NFE and ADG show partial correlations of FE with ADG after accounting for energy requirement for maintenance. Residual feed consumption was negatively associated with YWT, FE, and NFE, indicating a possible genetic improvement.

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Section: Introductionmentioning

confidence: 99%

Genetic parameter estimation of postweaning gain, feed intake, and feed efficiency for Hereford and Angus bulls fed two different diets

Fan

Bailey

Shannon

1995

Journal of Animal Science

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“…These positive values, for the most part, certainly express the fact that all animal dimensions increase simultaneously with weight rather than a morphological change. BAILEY et al (1971) noted a slightly lower conformation in Hereford selected on weight or even on conformation score at one year when the results were corrected for the correlated effect related to weight increase. Thus, if, for some reason, the aim is to change the morphological frame of cattle, this weight effect must be taken into account and the estimated genetic parameters considered after elimination of that effect.…”

Section: Genetic and Phenotypic Correlation Coefficientsmentioning

confidence: 90%

Genetic parameters of French beef breeds used in crossbreeding for young bull production I. - Live performance

RENARD¹

1985

Genet. Sel. Evol.

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Tendência genética na raça Gir

Filho

Silva

Alves

et al. 2000

Pesq. agropec. bras.

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RESUMO -A importância do peso e do ganho de peso para produção de bovino de corte tem sido responsável pela grande ênfase dada a essas características pelos criadores de diferentes raças. No entanto, é importante que haja um acompanhamento dos progressos genéticos que os diferentes programas de melhoramento vêm realizando, como forma de se ter uma avaliação global da raça. Assim, o presente trabalho teve o objetivo de avaliar as tendências genéticas dos ganhos de peso pré e pós-desmama na raça Gir. Foram utilizadas informações de 53.123 animais e as tendências genéticas foram calculadas pela regressão das médias anuais das diferenças esperadas na progênie sobre o ano de nascimento do bezerro. Verificaram-se tendências positivas dos efeitos genéticos direto e materno para ganho de peso pré-desmama e do efeito genético direto para ganho de peso pós-desmama. Os coeficientes de regressão foram 0,19, 0,06 e 0,026 g dia -1 , respectivamente, para os efeitos genéticos direto e materno sobre o ganho pré-desmama, e efeito genético direto para o ganho pós-desmama.Termos para indexação: Brasil, bovino de corte, ganhos de peso pré-desmama, ganho de peso pós-desmama, ganho genético. GENETIC TREND IN GIR BREEDABSTRACT -The importance of weight and weight gain for beef cattle production is responsible for the great emphasis that is devoted to these traits by breeders of different breeds. However, it is very important to maintain the animal breeding programs under surveillance in order to evaluate the genetic progress obtained by a breed as a whole. Thus, this study had the objective of evaluating the genetic trends for gain up to weaning and for gain from weaning to yearling considering the direct genetic and maternal genetic effects for preweaning gain and genetic direct effect for postweaning gain. The genetic trends were estimated by the regression of the annual average expected progeny differences on birth year of the calf. Positive trends were observed for preweaning gain, genetic direct and maternal genetic effect as well. This tendency was also observed for genetic direct effect for postweaning gain. The regression coefficients were 0.19, 0.06 and 0.026 g day -1 , for genetic direct and genetic maternal effects for preweaning gain, and for genetic direct effect for postweaning gain, respectively. Index terms: Brazil, beef cattle, preweaning gain, postweaning gain, genetic gain. nal resulta na necessidade de aumento da produtividade por unidade de área, animal e tempo, procurando-se, ainda, um produto de qualidade. Como essas demandas são relativamente recentes, seus reflexos numa raça como um todo podem ainda não se fazer sentir. Todavia, desde a introdução dos primeiros animais zebuínos no Brasil, a pecuária de corte iniciou um trabalho de seleção que, se no iní-cio, colocou mais ênfase no estabelecimento de um padrão racial bem definido, evoluiu rapidamente, priorizando características produtivas, notadamente, melhoria do desempenho ponderal.Esse enfoque ainda prevalece, apesar de, hoje, ele, sendo considerado concomi...

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Estimated Direct and Correlated Response to Selection for Performance Traits in Closed Hereford Lines under Different Types of Environments

Cited by 13 publications

References 0 publications

Genetic parameter estimation of postweaning gain, feed intake, and feed efficiency for Hereford and Angus bulls fed two different diets

Genetic parameter estimation of postweaning gain, feed intake, and feed efficiency for Hereford and Angus bulls fed two different diets

Genetic parameters of French beef breeds used in crossbreeding for young bull production I. - Live performance

Tendência genética na raça Gir

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