Estimativa de componentes de (co)variância de características de crescimento na raça Brahman utilizando inferência bayesiana

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estimativas de parâmetros genéticos para características de crescimento e de carcaça em ovinos de corte

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Potencial do composto flintisa anão de milho para melhoramento em condições de espaçamento reduzido e na safrinha

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Variabilidade genética em progênies de guapuruvu Schizolobium parahyba (Vell.) Blake

Pós-graduação em Ciência Florestal - FCA

Parâmetros genéticos para produção de leite e persistência de lactações múltiplas na raça Gir

Pós-graduação em Genética e Melhoramento Animal - FCAV

Modelos para estimação de componentes de (co)variância para pesos do nascimento à idade adulta de animais da raça Nelore

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Analysis of propagule pressure and genetic diversity in the invasibility of a freshwater apex predator: the peacock bass (genus Cichla)

Uma importante etapa na biologia da invasão é acessar variáveis biológicas que podem predizer o sucesso de invasão. O estudo da genética, evolução e interações entre invasores e espécies nativas no ambiente invadido pode prover uma oportunidade única para o estudo dos processos em genética de populações e a capacidade de uma espécie ampliar seu habitat. Nesse trabalho, nos utilizamos dados de marcadores de DNA microssatélites para testar se a variação genética é relacionada a pressão de propágulo na invasão bem sucedida do predador de topo (o ciclídeo Amazônico Cichla) nos rios do Sudeste Brasileiro. Populações invasoras de Cichla vem impactando negativamente diversas comunidades de água doce no Sudeste brasileiro deste 1960. A redução da variação genética foi observada em todas populações invasoras, tanto para Cichla kelberi (CK) como Cichla piquiti (CP). Por exemplo, a heterozigose foi menor no ambiente invadido quando comparada com as populações nativas da bacia Amazônica (CP HE = 0.179/0.44; CK HE = 0.258/0.536 respectivamente). Assim, apesar do sucesso da invasão de Cichla no sudoeste do Brasil, baixa diversidade genética foi observada nas populações introduzidas. Nós sugerimos que uma combinação de fatores, como as estratégias reprodutivas de Cichla, o efeito de "armadilha evolutiva" e a hipótese de resistências biótica superam o efeito que a diversidade genética depauperada exerce, sendo aspectos-chave na invasão desse predador de topo de cadeia.

Produtividade, estabilidade e adaptabilidade em progênies de eucalyptus urophylla s.t. blake

Pós-graduação em Agronomia - FEIS

The genetic characterization of myrmelachista roger assemblages (hymenoptera: formicidae: formicinae) in the atlantic forest of southeastern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Genetic parameters for body weight in buffaloes (Bubalus bubalis) in Colombia using random regression models

The objective of this research was to estimate (co) variance functions and genetic parameters for body weight in Colombian buffalo populations using random regression models with Legendre polynomials. Data consisted of 34,738 weight records from birth to 900 days of age from 7815 buffaloes. Fixed effects in the model were contemporary group and parity order of the mother. Random effects were direct and maternal additive genetic, as well as animal and maternal permanent environmental effects. A cubic orthogonal Legendre polynomial was used to model the mean curve of the population. Eleven models with first to sixth order polynomials were used to describe additive genetic direct and maternal effects, and animal and maternal permanent environmental effects. The residual was modeled considering five variance classes. The best model included fourth and sixth order polynomials for direct additive genetic and animal permanent environmental effects, respectively, and third-order polynomials for maternal genetic and maternal permanent environmental effects. The direct heritability increased from birth until 120 days of age (0.32 +/- 0.05), decreasing thereafter until one year of age (0.18 +/- 0.04) and increased again, reaching 0.39 +/- 0.09, at the end of the evaluated period. The highest maternal heritability estimates (0.11 +/- 0.05), were obtained for weights around weaning age (weaning age range is between 8 and 9.5 months). Maternal genetic and maternal permanent environmental variances increased from birth until about one year of age, decreasing at later ages. Direct genetic correlations ranged from moderate (0.60 +/- 0.060) to high (0.99 +/- 0.001), maternal genetic correlations showed a similar range (0.41 +/- 0.401 and 0.99 +/- 0.003), and all of them decreased as time between weighings increased. Direct genetic correlations suggested that selecting buffalos for heavier weights at any age would increase weights from birth through 900 days of age. However, higher heritabilities for direct genetic weights effects after 600 days of age suggested that selection for these effects would be more effective if done during this age period. A greater response to selection for maternal ability would be expected if selection used maternal genetic predictions for weights near weaning. (C) 2013 Elsevier B.V. All rights reserved.

Genetic parameters for production traits of dairy Gyr (Bos indicus) x Holstein cattle estimated with a random regression model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Random regression models to estimate genetic parameters for milk production of Guzerat cows using orthogonal Legendre polynomials

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Predicting breeding values for milk yield of Guzera (Bos indicus) cows using random regression models

Given the importance of Guzera breeding programs for milk production in the tropics, the objective of this study was to compare alternative random regression models for estimation of genetic parameters and prediction of breeding values. Test-day milk yields records (TDR) were collected monthly, in a maximum of 10 measurements. The database included 20,524 records of first lactation from 2816 Guzera cows. TDR data were analyzed by random regression models (RRM) considering additive genetic, permanent environmental and residual effects as random and the effects of contemporary group (CG), calving age as a covariate (linear and quadratic effects) and mean lactation curve as fixed. The genetic additive and permanent environmental effects were modeled by RRM using Wilmink, All and Schaeffer and cubic B-spline functions as well as Legendre polynomials. Residual variances were considered as heterogeneous classes, grouped differently according to the model used. Multi-trait analysis using finite-dimensional models (FDM) for testday milk records (TDR) and a single-trait model for 305-days milk yields (default) using the restricted maximum likelihood method were also carried out as further comparisons. Through the statistical criteria adopted, the best RRM was the one that used the cubic B-spline function with five random regression coefficients for the genetic additive and permanent environmental effects. However, the models using the Ali and Schaeffer function or Legendre polynomials with second and fifth order for, respectively, the additive genetic and permanent environmental effects can be adopted, as little variation was observed in the genetic parameter estimates compared to those estimated by models using the B-spline function. Therefore, due to the lower complexity in the (co)variance estimations, the model using Legendre polynomials represented the best option for the genetic evaluation of the Guzera lactation records. An increase of 3.6% in the accuracy of the estimated breeding values was verified when using RRM. The ranks of animals were very close whatever the RRM for the data set used to predict breeding values. Considering P305, results indicated only small to medium difference in the animals' ranking based on breeding values predicted by the conventional model or by RRM. Therefore, the sum of all the RRM-predicted breeding values along the lactation period (RRM305) can be used as a selection criterion for 305-day milk production. (c) 2014 Elsevier B.V. All rights reserved.

The Genetic Architecture of Climatic Adaptation of Tropical Cattle

Adaptation of global food systems to climate change is essential to feed the world. Tropical cattle production, a mainstay of profitability for farmers in the developing world, is dominated by heat, lack of water, poor quality feedstuffs, parasites, and tropical diseases. In these systems European cattle suffer significant stock loss, and the cross breeding of taurine x indicine cattle is unpredictable due to the dilution of adaptation to heat and tropical diseases. We explored the genetic architecture of ten traits of tropical cattle production using genome wide association studies of 4,662 animals varying from 0% to 100% indicine. We show that nine of the ten have genetic architectures that include genes of major effect, and in one case, a single location that accounted for more than 71% of the genetic variation. One genetic region in particular had effects on parasite resistance, yearling weight, body condition score, coat colour and penile sheath score. This region, extending 20 Mb on BTA5, appeared to be under genetic selection possibly through maintenance of haplotypes by breeders. We found that the amount of genetic variation and the genetic correlations between traits did not depend upon the degree of indicine content in the animals. Climate change is expected to expand some conditions of the tropics to more temperate environments, which may impact negatively on global livestock health and production. Our results point to several important genes that have large effects on adaptation that could be introduced into more temperate cattle without detrimental effects on productivity.

Random regression models for milk, fat and protein in Colombian Buffaloes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)