Genetic associations between stayability and reproductive and growth traits in Canchim beef cattle

Buzanskas, Marcos Eli; Grossi, D. A.; Baldi, Fernando; Barrozo, D.; Silva, L. O. C.; Torres, Roberto Augusto de Almeida; Munari, Danísio Prado; Alencar, M. M. de

doi:10.1016/j.livsci.2010.05.008

Cited by 48 publications

(36 citation statements)

References 30 publications

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“…A estimativa média de herdabilidade quanto à idade ao primeiro parto (0,05±0,02, Tabela 2) foi semelhante à obtida por Buzanskas et al (2010), que obtiveram herdabilidade de 0,04, por meio de inferência bayesiana, para a idade ao primeiro parto em fêmeas da raça Canchim. Entretanto, pelo método Máxima Verossimilhança Restrita (REML), outros autores obtiveram estimativas de herdabilidade levemente superiores, que variaram de 0,09 a 0,13, quanto à idade ao primeiro parto em fêmeas da raça Canchim (Silva et al, 2000;Talhari et al, 2003;Castro-Pereira et al, 2007;Baldi et al, 2008).…”

Section: Resultsunclassified

Parâmetros genéticos para características de crescimento e reprodução de bovinos da raça Canchim

Borba

Rey

Silva

et al. 2011

Pesq. agropec. bras.

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Resumo -O objetivo deste trabalho foi estimar parâmetros genéticos para idades ao primeiro (IPP) e segundo partos (ISP), idades ao primeiro (IPP PEN ) e segundo partos penalizadas (ISP PEN ), e a ocorrência de parto até os 38 meses de idade (PP 38 ), em bovinos da raça Canchim, bem como estimar as relações genéticas entre essas características e o peso (PE 420 ) de machos e femêas e a circunferência escrotal (CE 420 ) de novilhos, medidos aos 420 dias de idade. Foram estimados parâmetros genéticos em análises bicaracterísticas, por meio de inferência bayesiana. As análises foram realizadas entre CE 420 e PE 420 e as características reprodutivas medidas em fêmeas. As características reprodutivas das fêmeas devem apresentar baixa resposta à seleção, e mudanças no manejo e nas condições ambientais melhoram tais características. A seleção quanto ao maior peso aos 420 dias de idade não deve provocar mudanças nas características reprodutivas em fêmeas, enquanto a seleção para o aumento da circunferência escrotal, na mesma idade, contribui para melhorar tais características.Termo para indexação: bovinos de corte, circunferência escrotal, idade ao parto, ocorrência de parição, peso. Genetic parameters for growth and reproductive traits of Canchim breedAbstract -The objective of this work was to estimate genetic parameters for age at first (AFC) and at second (ASC) calvings, penalized age at first (AFC PEN ) and at second (ASC PEN ) calvings, and occurrence of calving until 38 months of age (PP 38 ) in Canchim breed, as well as to estimate the genetic correlations between these traits with weight (PE 420 ) of males and females, and scrotal circumference (CE 420 ) measured at 420 days of age. Genetic parameters were estimated by two-trait analyses using the Bayesian inference. The analyses were performed between CE 420 and PE 420 , and the reproductive traits measured in the females. The female reproductive traits should show low response to selection, and changes in the management and environmental conditions improve these traits. Selection for the higher weight at 420 days of age does not change female reproductive traits, while selection to increase scrotal circumference, at the same age, contributes to improve such traits.

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Section: Resultsunclassified

Parâmetros genéticos para características de crescimento e reprodução de bovinos da raça Canchim

Borba

Rey

Silva

et al. 2011

Pesq. agropec. bras.

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“…According to Buzanskas et al (2010), females that start their reproductive life early, the production costs may also be discounted early, and this may contribute toward an increase in the number of calves born per cow in a certain period of time. These results indicate that precocious cows have a higher chance of not being culled before 6 years of age.…”

Section: Genetic Correlationsmentioning

confidence: 99%

Genetic relationship between growth and reproductive traits in Nellore cattle

Júnior

Eler

Ferraz

et al. 2012

Animal

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The objective of this study was to evaluate the genetic relationship between postweaning weight gain (PWG), heifer pregnancy (HP), scrotal circumference (SC) at 18 months of age, stayability at 6 years of age (STAY) and finishing visual score at 18 months of age (PREC), and to determine the potential of these traits as selection criteria for the genetic improvement of growth and reproduction in Nellore cattle. The HP was defined as the observation that a heifer conceived and remained pregnant, which was assessed by rectal palpation at 60 days. The STAY was defined as whether or not a cow calved every year up to the age of 6 years, given that she was provided the opportunity to breed. The Bayesian linear-threshold analysis via the Gibbs sampler was used to estimate the variance and covariance components applying a multitrait model. Posterior mean estimates of direct heritability were 0.15 6 0.00, 0.42 6 0.02, 0.49 6 0.01, 0.11 6 0.01 and 0.19 6 0.00 for PWG, HP, SC, STAY and PREC, respectively. The genetic correlations between traits ranged from 0.17 to 0.62. The traits studied generally have potential for use as selection criteria in genetic breeding programs. The genetic correlations between all traits show that selection for one of these traits does not imply the loss of the others.

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“…In the definition of longevity in the herd reported by Buzanskas et al (2010), cows aged around 76 months with at least three calvings are considered to be successful and cows of the same age with fewer than three calvings are considered to be failures. A single discard criterion is taken for the whole data set in defining this trait, and only the cows that attain a certain age are considered in the analysis.…”

Section: Introductionmentioning

confidence: 99%

Characterization of the variable cow's age at last calving as a measurement of longevity by using the Kaplan–Meier estimator and the Cox model

Caetano

Rosa

Savegnago

et al. 2013

Animal

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In most studies on beef cattle longevity, only the cows reaching a given number of calvings by a specific age are considered in the analyses. With the aim of evaluating all cows with productive life in herds, taking into consideration the different forms of management on each farm, it was proposed to measure cow longevity from age at last calving (ALC), that is, the most recent calving registered in the files. The objective was to characterize this trait in order to study the longevity of Nellore cattle, using the Kaplan-Meier estimators and the Cox model. The covariables and class effects considered in the models were age at first calving (AFC), year and season of birth of the cow and farm. The variable studied (ALC) was classified as presenting complete information (uncensored 5 1) or incomplete information (censored 5 0), using the criterion of the difference between the date of each cow's last calving and the date of the latest calving at each farm. If this difference was .36 months, the cow was considered to have failed. If not, this cow was censored, thus indicating that future calving remained possible for this cow. The records of 11 791 animals from 22 farms within the Nellore Breed Genetic Improvement Program ('Nellore Brazil') were used. In the estimation process using the Kaplan-Meier model, the variable of AFC was classified into three age groups. In individual analyses, the logrank test and the Wilcoxon test in the Kaplan-Meier model showed that all covariables and class effects had significant effects (P , 0.05) on ALC. In the analysis considering all covariables and class effects, using the Wald test in the Cox model, only the season of birth of the cow was not significant for ALC (P . 0.05). This analysis indicated that each month added to AFC diminished the risk of the cow's failure in the herd by 2%. Nonetheless, this does not imply that animals with younger AFC had less profitability. Cows with greater numbers of calvings were more precocious than those with fewer calvings.

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Genetic associations between stayability and reproductive and growth traits in Canchim beef cattle

Cited by 48 publications

References 30 publications

Parâmetros genéticos para características de crescimento e reprodução de bovinos da raça Canchim

Parâmetros genéticos para características de crescimento e reprodução de bovinos da raça Canchim

Genetic relationship between growth and reproductive traits in Nellore cattle

Characterization of the variable cow's age at last calving as a measurement of longevity by using the Kaplan–Meier estimator and the Cox model

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