Variance and Covariance Estimates for Maternally Influenced Beef Growth Traits2

Bertrand, J. K.; Benyshek, L. L.

doi:10.2527/jas1987.643728x

Cited by 43 publications

(45 citation statements)

References 4 publications

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“…The heritability estimate of the maternal additive genetic effect (h 2 m ) for weight at weaning was higher than the values reported by Albuquerque & Meyer (2001) The value of 0.30 estimated for the heritability of direct genetic effect (h 2 a ) for weight at weaning (Table 3) was higher than 0.28 estimated by Bertrand & Benyshek (1987) for the Brangus breed and of 0.23 reported by Everling et al Pons et al (1989) for the Hereford breed (0.37). Somehow, the obtained heritability values are included in the range found in the literature for both pure populations and to crossbreed.…”

Section: Resultscontrasting

confidence: 48%

Genetic parameters and phenotypic and genetic trends for weight at weaning and visual scores during this phase estimated for Angus-Nellore crossbred young bulls

et al. 2010

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-Genetic parameters and genetic and phenotypic trends were estimated for weight at weaning (WW) and visual scores (VS) of conformation (C), precocity (P), musculature (M) and navel (N) for Angus × Nellore crossbred calves.It was used 39,676 records from pre-weaning phase of animals born from 1992 to 2002 in mid-western, southeastern and southern Brazil. The components of covariance were estimated using REML, in animal model, considering as random the maternal and direct additive genetic effects, and as fixed, the effects of contemporaneous group, the genetic group of the animal and of the cow, and as covariates the age of the calf at weaning and the age of the cow at calving, both on days and with linear and quadratic effects, besides direct (DH) and maternal heterosis (MH), both with only the linear effect. Estimates of direct and maternal heritability were 0.30 and 0.19, respectively, for WW, whereas VSs ranged from 0.16 to 0.20 and from 0.09 to 0.16, which indicates the possibility to obtain genetic gain through selection. It is expected answer correlated to C, P and for M when selection is practiced for weight at weaning is expected, as well as for P and M when selection is practiced for C.The direct and maternal genetic trends for WW (g/year) and for C, P, M and N (points/year) were: 221.0 and -312.0; 0.0022 and 0.00003; 0.0010 and 0.0001; 0.0013 and -0.0008; 0.0010 and 0.00009, respectively, while the phenotypic were: -685.2; -0.0102; -0.0219; -0.0256 and -0.0453, which highlights the need to adopt criteria for identifying young bulls of higher genetic value for WW and VSs.Key Words: beef cattle, cross-breeding, genetic evaluation, genetic progress, morphologic evaluationParâmetros genéticos e tendências genéticas e fenotípicas para peso a desmama e escores visuais nessa fase estimados para tourinhos mestiços Angus-Nelore RESUMO -Foram estimados parâmetros genéticos e tendências genéticas e fenotípicas para peso a desmama (PD) e para os escores visuais (EVs) de conformação (C), precocidade (P), musculatura (M) e umbigo (U), para bezerros produtos do cruzamento entre as raças Angus e Nelore. Foram utilizados 39.676 registros da fase pré-desmama, de animais nascidos entre os anos de 1992 e 2002, nas regiões Centro-oeste, Sudeste e Sul do Brasil. Os componentes de (co)variâncias foram estimados utilizando-se o REML, em modelo animal, considerando como aleatórios, os efeitos genéticos aditivos diretos e maternos e, como fixos, os efeitos de grupo de contemporâneos, grupo genético do animal e da vaca e, como covariáveis a idade do bezerro a desmama, a idade da vaca ao parto, ambas em dias e com efeitos linear e quadrático, além da heterose direta (HD) e a heterose materna (HM), ambas somente com efeito linear. As estimativas de herdabilidade diretas e maternas foram 0,30 e 0,19, respectivamente para PD, enquanto que para os EVs variaram de 0,16 a 0,20 e de 0,09 a 0,16, indicando ser possível obter ganho genético através da seleção. É esperada resposta correlacionada em C, P, e M quando a seleção for pr...

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Section: Resultscontrasting

confidence: 48%

Genetic parameters and phenotypic and genetic trends for weight at weaning and visual scores during this phase estimated for Angus-Nellore crossbred young bulls

et al. 2010

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“…Brown and Galvez (1969) were higher than later estimates in the literature for beef (Koch 19721, Bwfening et al 1982;Bertrand and Benyshek 1987) and dairy cattle (Philipsson 1976 (Trus 1986). The choice of relative emphasis should be determined primarily by breeding system and practical considerations.…”

contrasting

confidence: 49%

Genetic Parameters for Maternal Traits in Beef Cattle

Trus¹,

Wilton²

1988

Can. J. Anim. Sci.

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Direct (D) and maternal (M) parameters for birth weight (BW), preweaning gain (WG) and calving ease (CE) were estimated for Angus (AN), Hereford (HE), Charolais (CH), Simmental (SM) and Shorthorn (SS). Data for the study were collected by Agriculture Canada from 1973 to 1983 for use in the National Sire Monitoring Program. Variances were estimated for each breed by a modified Method IV applied to a sire-maternal grandsire model with herd-year-seasons and age of dam × sex of calf as fixed effects. Genetic correlations (D/M) between D and M effects for WG in AN, HE, SS, CH and SM were −0.54, −0.42, −0.14, −0.26 and −0.45, respectively. Corresponding estimates of direct heritability for WG were 0.39, 0.30, 0.39, 0.27 and 0.43 and of maternal heritability 0.21, 0.27, 0.26, 0.16 and 0.20. Estimates for BW were similar to those for WG. Estimates of the D/M correlation for CE were −0.43, −0.15, −0.32, −0.74 and −0.27, of the direct heritability 0.28, 0.17, 0.19, 0.33 and 0.21, and of the maternal heritability 0.22, 0.13, 0.19, 0.23 and 0.27 for AN, HE, SS, CH and SM, respectively. Genetic trend and the introduction of new genetic lines are expected to have influenced parameter estimates. Due to negative D/M correlation estimates and moderate maternal heritabilities, selection for both the D and M components of maternal traits is advised. Key words: Variance, direct, maternal, heritability, genetic correlation, beef cattle

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“…However, these estimates were not significantly different from zero. Maternal genetic effects have been described in domestic mammals such as swine (18,21) and beef cattle (3,15) and represent an environmental effect on the growth of offspring from birth to weaning. However, dairy calves are separated from their dams at birth so that the influence of the dam would be only through intrauterine environment.…”

Section: Resultsmentioning

confidence: 99%

“…2 Phenotypic variances: (kilograms) 2 /1000 for milk, kilograms squared for fat, and (percentage) 2 × 10,000 for fat percentage. ditive direct and maternal effects, Model [4] was as Model [3] but excluding sire by herd interactions effects, Model [5] was as Model [3] but excluding cytoplasmic effects, and Model [6] was as Model [5] but excluding sire by herd interaction effects.…”

Section: Methodsmentioning

confidence: 99%

“…A complete animal model was described as y = Xb + Zg + Mm + Ps + Dc + Wpe + e [1] where y = vector of observations, b = vector of fixed effects (herd-year-seasons), g = vector of additive direct genetic effects of animals, m = vector of additive maternal genetic effects, s = vector of sire by herd interaction effects, c = vector of cytoplasmic effects, pe = vector of permament environmental effects, e = vector of residual effects, and X, Z, M, P, D, and W = incidence matrices that associate the appropriate effects to y. Another five single-trait animal models were fitted: Model [2] was as Model [1] but excluding cytoplasmic effects, Model [3] was as Model [1] but excluding additive maternal effects and covariance between ad- 1 g = Additive direct genetic effect, m = additive maternal genetic effect, gm = covariance direct and maternal genetic effects, sh = sire by herd interaction effect, c = cytoplasmic line effect, p = permanent environmental effect, and e = residual. 2 Phenotypic variances: (kilograms) 2 /1000 for milk, kilograms squared for fat, and (percentage) 2 × 10,000 for fat percentage.…”

Section: Methodsmentioning

confidence: 99%

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Variances of Direct Genetic Effects, Maternal Genetic Effects, and Cytoplasmic Inheritance Effects for Milk Yield, Fat Yield, and Fat Percentage

Albuquerque

Keown

Vleck

1998

Journal of Dairy Science

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Milk yield, fat yield, and fat percentage during the first three lactations were studied using New York Holsteins that were milked twice daily over a 305-d, mature equivalent lactation. Those data were used to estimate variances from direct and maternal genetic effects, cytoplasmic effects, sire by herd interaction, and cow permanent environmental effects. Cytoplasmic line was traced to the last female ancestor using DHI records from 1950 through 1991. Records were 138,869 lactations of 68,063 cows calving from 1980 through 1991. Ten random samples were based on herd code. Samples averaged 4926 dams and 2026 cytoplasmic lines. Model also included herd-year-seasons as fixed effects and genetic covariance for direct-maternal effects. Mean estimates of the effects of maternal genetic variances and directmaternal covariances, as fractions of phenotypic variances, were 0.008 and 0.007 for milk yield, 0.010 and 0.010 for fat yield, and 0.006 and 0.025 for fat percentage, respectively. Average fractions of variance from cytoplasmic line were 0.011, 0.008, and 0.009 for milk yield, fat yield, and fat percentage. Removal of maternal genetic effects and covariance for maternal direct effects from the model increased the fraction of direct genetic variance by 0.014, 0.021, and 0.046 for milk yield, fat yield, and fat percentage; little change in the fraction was due to cytoplasmic line. Exclusion of cytoplasmic effects from the model increased the ratio of additive direct genetic variance to phenotypic variance by less than 2%. Similarly, when sire by herd interaction was excluded, the ratio of direct genetic variance to phenotypic variance increased 1% or less.(

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Variance and Covariance Estimates for Maternally Influenced Beef Growth Traits2

Cited by 43 publications

References 4 publications

Genetic parameters and phenotypic and genetic trends for weight at weaning and visual scores during this phase estimated for Angus-Nellore crossbred young bulls

Genetic parameters and phenotypic and genetic trends for weight at weaning and visual scores during this phase estimated for Angus-Nellore crossbred young bulls

Genetic Parameters for Maternal Traits in Beef Cattle

Variances of Direct Genetic Effects, Maternal Genetic Effects, and Cytoplasmic Inheritance Effects for Milk Yield, Fat Yield, and Fat Percentage

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