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Paterno F.M.,São Paulo State University | Buzanskas M.E.,Federal University of Paraiba | Koury Filho W.,Brazil Com Z Zootecnia Tropical | Lobo R.B.,Associacao Nacional de Criadores e Pesquisadores ANCP | Queiroz S.A.,São Paulo State University
Journal of Agricultural Science | Year: 2017

Genetic parameters for visual assessment traits measured at 487 days of age (body structure (BS), finishing precocity (FP) and muscling (MS)), body weight at 450 days of age (W450), age at first calving (AFC), heifer pregnancy (HP) and stayability (STAY, i.e. the probability of a cow to produce at least three calves before reaching 76 months of age) were estimated in Nellore cattle, seeking to include these traits in the selection criteria for dams. The statistical models included additive genetic and residual random effects using single- and two-trait Bayesian analyses. The average heritability estimates were equal to 0·37 for BS, 0·42 for FP, 0·37 for MS and 0·48 for W450. Age at first calving had a low average heritability estimate (0·13), while HP and STAY estimates were higher (0·36 and 0·24, respectively). The genetic correlations between AFC, HP and STAY with visual assessment traits and body weight were favourable, indicating that selecting animals with higher BS, FP, MS and W450 values will result in the indirect selection of animals with lower AFC and successful scores for HP and STAY. The selection of heifers that present an early pregnancy should anticipate AFC and improve HP in the current herd. Except for AFC, the heritability and genetic correlation estimates between the studied traits justify their inclusion in the selection criteria of the Nellore breeding programme. © 2017 Cambridge University Press.


Marcondes C.R.,Embrapa Pecuaria Sudeste | Araujo R.O.,University of Brasilia | Vozzi P.A.,Instituto Nacional de Tecnologia Agropecuaria | Gunski R.J.,Ciencias Biologicas UNIPAMPA | And 2 more authors.
Archivos de Zootecnia | Year: 2011

The aim of this study was to estimate the genetic parameters of the index scrotal circumference/ weight standarized for 365 days of age (IND365), via bayesian inference, in two separate models of analysis on Nellore animals born in the Tocantins state, Brazil. The file was composed of 693 records of the IND365 divided into 16 contemporaneous group. Variance components were analyzed via bayesian inference, through the programs in Fortran language. Sampling of every 100 or 500 rounds and a little conservative burn-in can be implemented. Means of direct heritabilities were 0.18 (with and without maternal effect) and 0.14 for maternal heritabilities. These results suggest that the IND365 can be used as alternative criterion in breeding programs to Nellore cattle and respond satisfactorily to the selection process.


Vargas G.,niv Estadual Paulista | Buzanskas M.E.,niv Estadual Paulista | Guidolin D.G.F.,niv Estadual Paulista | Grossi D.A.,University of Guelph | And 5 more authors.
Tropical Animal Health and Production | Year: 2014

Beef cattle producers in Brazil use body weight traits as breeding program selection criteria due to their great economic importance. The objectives of this study were to evaluate different animal models, estimate genetic parameters, and define the most fitting model for Brahman cattle body weight standardized at 120 (BW120), 210 (BW210), 365 (BW365), 450 (BW450), and 550 (BW550) days of age. To estimate genetic parameters, single-, two-, and multi-trait analyses were performed using the animal model. The likelihood ratio test was verified between all models. For BW120 and BW210, additive direct genetic, maternal genetic, maternal permanent environment, and residual effects were considered, while for BW365 and BW450, additive direct genetic, maternal genetic, and residual effects were considered. Finally, for BW550, additive direct genetic and residual effects were considered. Estimates of direct heritability for BW120 were similar in all analyses; however, for the other traits, multi-trait analysis resulted in higher estimates. The maternal heritability and proportion of maternal permanent environmental variance to total variance were minimal in multi-trait analyses. Genetic, environmental, and phenotypic correlations were of high magnitude between all traits. Multi-trait analyses would aid in the parameter estimation for body weight at older ages because they are usually affected by a lower number of animals with phenotypic information due to culling and mortality. © 2014, Springer Science+Business Media Dordrecht.


PubMed | Associacao Nacional de Criadores e Pesquisadores ANCP, São Paulo State University, Federal University of Paraiba and Brazil com Z Zootecnia Tropical
Type: | Journal: Tropical animal health and production | Year: 2016

The aims of our study were to estimate genetic parameters for body weight and visual scores and to evaluate their inclusion as selection criteria in the Nelore breeding program in Brazil. The traits studied were the body weight adjusted to 210 (W210) and to 450 (W450) days of age and visual scores for body structure, finishing precocity, and muscling evaluated at weaning (BS


Grupioni N.V.,São Paulo State University | Guidolin D.G.F.,Anhanguera-Uniderp University | Venturini G.C.,São Paulo State University | Lobo R.B.,Associacao Nacional de Criadores e Pesquisadores ANCP | Munari D.P.,São Paulo State University
Revista Caatinga | Year: 2015

This study aimed to estimate genetic parameters and genetic trends for reproductive traits and testicular growth in Guzerá cattle. Variance components were estimated through two-trait analyses using the restricted maximum likelihood method. To age at first calving (AFC), first calving interval (FC1), gestation period (GP), and scrotal circumference at 365 and 450 days (SC365 and SC450, respectively) were included the random residual and additive genetic effects and the fixed effects of contemporary group. The covariates cows age at calving and AFC were included in the model for SC365 and SC450 (linear and quadratic effects) and for FC1 (linear effect), respectively. For GP, The random maternal genetic effects were also considered. Heritability estimates ranged from 0.08 ± 0.05 (FC1) to 0.48 ± 0.11 (GP). Genetic trends were significant (P <0.05) for all traits with the exception of the maternal genetic effect of GP. The SC365, SC450 and GP traits, could be used as selection criteria for presenting additive genetic variability sufficient to respond to the selec-tion process. The genetic correlation between AFC and scrotal circumferences (SC365 and SC450) indicates that selection for scrotal circumference in these ages, reduce the AFC of the females. © 2015, Universidade Federal Rural do Semi-Arid. All rights reserved.


Magnabosco C.U.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Lopes F.B.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Miyagi E.S.,Federal University of Goais | Lobo R.B.,Associacao Nacional de Criadores e Pesquisadores ANCP | Sainz R.D.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária
Revista Ciencia Agronomica | Year: 2014

The objective of the present study was to analyze the phenotypic inter-relationships between growth, feed intake and carcass traits in polled Nellore cattle, as well as to determine which bulls produced the most efficient progeny. The experiment was conducted in the feedlot of the Guaporé Pecuária (Livestock) Company, OB Brand. The following traits were analyzed: initial live weight (ILW); final live weight (FLW); average daily gain (ADG); dry matter intake (DMI); gain:feed (G:F); residual feed intake (RFI); rib-eye area (REA); rump fat thickness (RF); backfat thickness at the 12th-13th rib (BF); weighted fat score (WF); and intramuscular fat percentage (IMF). Both univariate and multivariate analyses were performed to analyze the inter-relationships between the studied traits. No significant phenotypic associations were observed between growth, carcass traits and residual feed intake, while the correlation between RFI and G:F was negative. Therefore, RFI may be used to select more nutritionally efficient animals without compromising growth or adult size. The selection of bulls with progeny showing low residual feed intake is recommended, as selection for low RFI tends to improve feed efficiency without compromising growth and development.


de Faria C.U.,Federal University of Uberlandia | de Andrade W.B.F.,São Paulo State University | de Pereira C.F.,Federal University of Uberlandia | da Silva R.P.,Federal University of Uberlandia | Lobo R.B.,Associacao Nacional de Criadores e Pesquisadores ANCP
Ciencia Rural | Year: 2015

The purpose of this study was to estimate the genetic parameters for carcass traits of longissimus muscle area (LMA), backfat thickness (BF) and rump fat thickness (RF), measured by ultrasound in Polled Nelore cattle raised in the Cerrado biome. The data set was obtained from bovines Polled Nelore, proceeding from participant farms of the Nelore Brazil Program of the National Association of Breeders and Researchers, raised on pasture, from the Brazilian states that have the largest continuous areas of the Cerrado. Heritabilities were estimated by Gibbs Sampling using the MTGSAM software (Multiple Trait using Gibbs Sampler under Animal Model). The heritability estimates were 0.30, 0.17 and 0.25 for LMA, BF and RF, respectively. The results indicate that carcass traits have high genetic variability and should be included in breeding programs. © 2015, Universidade Federal de Santa Maria. All rights reserved.


Caetano S.L.,São Paulo State University | Savegnago R.P.,São Paulo State University | Boligon A.A.,São Paulo State University | Ramos S.B.,São Paulo State University | And 3 more authors.
Livestock Science | Year: 2013

The objective of this study was to estimate genetic parameters for female mature weight (FMW), age at first calving (AFC), weight gain from birth to 120 days (WG_B_120), from 210 to 365 days (WG_210_365), rib eye area (REA), back fat thickness (BF), rump fat (RF) and body weight at scanning date (BWS) using single and multiple-trait animal models by the REML method from Nellore cattle data. The estimates of heritability ranged from 0.163±0.011 for WG_210_365 to 0.309±0.028 for RF using the single-trait model and from 0.163±0.010 for WG_210_365 to 0.382±0.025 for BWS using the multiple-trait model. The estimates of genetic correlations ranged from -0.35±0.08 between AFC with BF to 0.69±0.04 between WG_B_120 with BWS. Selection for weights gains, REA, and BWS can improve FMW. © 2013 Elsevier B.V.

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