Produtividade acumulada como critério de seleção em fêmeas da raça nelore

Schwengber, Eduardo Brum; Bezerra, Luiz Antônio Framartino; Lôbo, Raysildo Barbosa

doi:10.1590/s0103-84782001000300020

Cited by 17 publications

(11 citation statements)

References 3 publications

(3 reference statements)

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“…The averages in this study were lower than those of Rosa (1999) who reported averages of 144 kg and those of Schwengber et al (2001) who reported a mean of 135 kg. However, the change in the denominator of the equation is emphasized in this study.…”

Section: Resultscontrasting

confidence: 90%

“…The variance components and heritability estimation for the average annual productivity are shown in Besides being very close to each other (0.15, 0.15 and 0.16 for the COWPROD_NAJ, COWPROD_AJFIX and COWPROD_AJFIN), the heritability estimates also agreed with the results published by Rosa (1999) and by Schwengber et al (2001) who reported values of 0.19 and 0.15, respectively. Baldi et al (2008) have also reported a heritability value of 0.15 for the amount, in kg, of weaned calves per year of stayability of the cow in the herd.…”

Section: Resultssupporting

confidence: 86%

“…However, the change in the denominator of the equation is emphasized in this study. Performing the calculation of the COWPROD based on Lôbo's equation (1996), used by Schwengber et al (2001), the average would be 129.5 ± 34.2, 124.3 ± 29.4 and 122.4 ± 29.0 kg, for COWPROD_NAJ, COWPROD_AJFIX and COWPROD_AJFIN, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…For evaluating productive efficiency, PAC could be a more adequate index than stayability in the livestock, as it allows the inclusion of the young females that have only one calf, enabling the prediction of the genetic merit for younger bulls. Schwengber et al (2001) report a heritability estimate of 0.15 for that trait. Heritability could be of a sufficient magnitude for the use of PAC as criterion for bull selection, regarding reproductive efficiency, replacing in this case stayability.…”

Section: Introductionmentioning

confidence: 99%

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Genetic analysis of average annual productivity of Nellore breeding cows (COWPROD)

Eler

Ferraz²,

Balieiro³

et al. 2008

Genet. Mol. Res.

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ABSTRACT. With the aim of estimating the coefficient of heritability of average annual productivity of Nellore cows (COWPROD), a data set from 24,855 animals with known pedigree was analyzed. COWPROD is defined as the amount (in kilograms) of weaned calves produced yearly by one cow during her remaining time in herd ignoring a fixed period of 365 days. COWPROD was calculated regarding three standards: a) based on the post-weaning weight from the calves ignoring any kind of adjustment (COWPROD_NAJ), b) adjusted weight for the fixed effects (COWPROD_ AJFIX) and c) adjusted weight for the fixed effects and for the genetic merit of the sire (COWPROD_AJFIN). The obtained heritabilities were 0.15, 0.15 and 0.16 for COWPROD_NAJ, COWPROD_AJFIX and COWPROD_ AJFIN, respectively. A complete set composed of 105,158 COWPROD records on 130,740 animals in pedigree was also analyzed for predicting the genetic merit of all animals in the data set and for the calculation of the genetic, phenotypic and residual trends. Ranking correlation was high for the adjusted and non-adjusted data, yet, for some of the animals, the difference among the genetic values was large. This would be an indication that it would be better to work always with the adjusted weaning weights. The genetic trend was positive, but was of small magnitude (0.26% of the trait average) and the residual trend was negative as a consequence of the large intensification of the production system, which has been occurring in the last years in the farms studied. The phenotypic trend was also negative and intermediate between the genetic and the residual ones.

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Section: Resultscontrasting

confidence: 90%

Section: Resultssupporting

confidence: 86%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Genetic analysis of average annual productivity of Nellore breeding cows (COWPROD)

Eler

Ferraz²,

Balieiro³

et al. 2008

Genet. Mol. Res.

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“…No geral, os resultados obtidos neste estudo encontram-se próximos aos relatados na literatura para esta mesma raça, os quais variam de 0,10 a 0,19 (PEREIRA et al, 2000;SCHWENGBER et al, 2001;PEREIRA et al, 2002e BOLIGON et al, 2007. Por outro lado, VAN MELIS et al (2001) e PEREIRA et al (2002 relataram estimativas de herdabilidade para IPP praticamente nulas, ou seja, 0,01 e 0,02, respectivamente.…”

Section: Resultsunclassified

Parâmetros genéticos para idade ao primeiro parto estimados por diferentes modelos para rebanhos da raça Nelore

et al. 2008

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RESUMO Com objetivo de estimar parâmetros genéticos e estudar a utilização de diferentes efeitos em avaliações genéticas para idade ao primeiro parto (IPP) por diferentes modelos, foram utilizados registros de IPP de animais da raça (SAS, 2003). While considering year and season of calving in the analysis models (M2 and M3), it was produced a bigger R², indicating that those models could explain, in a larger scale, the existing differences between the animals for AFC. The heritabilities estimated were of low magnitude (0,14 and 0,15). The correlations between the GV obtained by the different models were . 73 (M1 x M2); .91 (M2 x M3) and .66 (M1 x M3).

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Genetic analysis on accumulated productivity and calving intervals in Nelore cattle

Grossi

Berton

Buzanskas

et al. 2015

Trop Anim Health Prod

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The aim of this study was to estimate genetic parameters for accumulated productivity (ACP), first calving interval (CI1), second calving interval (CI2), and mean calving interval (MCI) in Nelore beef cattle. The ACP trait is a reproduction index and comprises the total number of calves born per dam, weight of weaned calves, and age of the dam at calving. Genetic parameters were estimated by the average information restricted maximum likelihood method in two-trait analyses. The average heritability estimate for ACP was 0.17 (0.03). For CI1, CI2, and MCI, the heritability estimates were 0.02, 0.02, and 0.06, respectively. Genetic correlations between ACP with CI1, CI2, and MCI were -0.16 ± 0.47, -0.29 ± 0.53, and -0.40 ± 0.27, respectively. Despite of the low heritability estimates obtained in our study, reproduction traits should be further studied and their inclusion in the selection criteria must be evaluated in order to improve the performance of females because these traits are of great economic importance in beef cattle. Accumulated productivity could contribute to decrease the mean calving interval in Nelore cattle.

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Produtividade acumulada como critério de seleção em fêmeas da raça nelore

Cited by 17 publications

References 3 publications

Genetic analysis of average annual productivity of Nellore breeding cows (COWPROD)

Genetic analysis of average annual productivity of Nellore breeding cows (COWPROD)

Parâmetros genéticos para idade ao primeiro parto estimados por diferentes modelos para rebanhos da raça Nelore

Genetic analysis on accumulated productivity and calving intervals in Nelore cattle

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