Júlio César de Souza

Tendência Genética dos Efeitos Direto e Materno sobre os Pesos à Desmama e Pós-Desmama de Bovinos da Raça Tabapuã no Brasil

Data related to weights of animals of the Tabapua breed, born from 1959 to 1996, in several areas of Brazil, were analyzed with the objective of evaluating the direct and maternal genetic trends, for body weights adjusted for 205 (W205), 365 (W365) and 550 (W550) days of age. The (co)variance component estimates used in the calculation of the breeding values were obtained by the restricted maximum likelihood method (REML), with a model containing the random additive direct, maternal and permanent environmental effects, and the fixed effects of contemporary group (unit of the federation, farm, sex, season and year of birth of the animal) and the covariable age of the cow at calving (linear and quadratic effects). The genetic trends of the direct and maternal genetic effects were estimated by the regression of the breeding value annual means on year of birth of the animals. The genetic trends of the direct effects were 0.134, 0.199 and 0.276 kg/year, for W205, W365 and W550, respectively. The estimates of the maternal genetic trends were, in the same order, 0.019, -0.010 and -0.022 kg/year, respectively. Due to the existing genetic variability on the traits, the genetic changes attained are bellow the possible ones.

Composição físico-química e produção do leite de búfalas da raça Mediterrâneo no oeste do Estado de São Paulo

The objective of this study was to evaluate milk yield and some physico-chemical characteristics of milk from Mediterranean buffalo cows raised in western Sao Paulo. A total of 1438 observations was collected from 152 lactations that occurred from 1985 to 1995, at the Experimental Station of Andradina. The data were analyzed by means of the GLM procedure of SAS. The statistical model for milk production had month and lactation as fixed effects. The model for chemical constituents included milk yield as covariate. All effects were significant. The overall adjusted means were 4.52 kg, 4.13%, 6.59%; 17.01%, 10.47% and 18.98°D for milk production, protein, fat and total solids, solids not fat and titratable acidity, respectively. High nutrient contents were observed, which shows the good quality of the product.

Melhoramento e estrutura populacional em bubalinos da raça Mediterrâneo no Brasil

O objetivo deste trabalho foi avaliar a estrutura populacional e os progressos geneticos, fenotipicos e ambientais de caracteristicas de desenvolvimento ponderal, em bubalinos da raca Mediterrâneo. Foram utilizadas informacoes dos pesos ajustados aos 205, 365 e 550 dias de idade, de 6.243 bubalinos nascidos no periodo de 1974 a 2003, provenientes de quatro fazendas. As estimativas dos coeficientes de herdabilidade foram altas para os pesos ajustados nas tres idades. Os rebanhos apresentaram ganho genetico positivo quanto a essas tres caracteristicas, porem, aquem do possivel, provavelmente em razao da selecao baseada somente no fenotipo, realizada pelos produtores. Para aumento nos ganhos geneticos, sao necessarios a reducao do intervalo de geracao, o aumento do tamanho efetivo, o uso de reprodutores avaliados com base nos valores geneticos preditos pelo BLUP e o controle dos acasalamentos de animais aparentados.

Parâmetros e tendências da produção de leite em bubalinos da raça Murrah no Brasil

Objetivou-se estimar os parâmetros e avaliar as tendencias genetica e fenotipica para a producao de leite ajustada aos 305 dias em bubalinos da raca Murrah nascidos no periodo de 1982 a 2003. Os parâmetros e os valores geneticos foram estimados por meio do aplicativo MTDFREML. A tendencia genetica foi estimada pela regressao dos valores geneticos sobre o ano de nascimento, por duas metodologias: 1) regressao linear; 2) regressao por meio de polinomios articulados utilizando-se a funcao de alisamento spline. A herdabilidade e a repetibilidade estimadas foram de 0,20 e 0,36, respectivamente. As tendencias (regressao linear) fenotipica e genetica foram significativas e iguais a 32,86 e 0,85 kg/ano, respectivamente. O ganho genetico foi positivo, constatando-se instabilidade na tendencia genetica no decorrer dos anos, com periodos de ganhos e outros de perdas geneticas. A maior parte do ganho observado em alguns periodos resultou de melhorias nas condicoes ambientais.

Tendências genéticas para características relacionadas à velocidade de crescimento em bovinos Nelore na região nordeste do Brasil

The objectives of this work were to estimate the genetic parameters and the genetic trends of the direct and maternal effects for the trait days to gain 160 kg (D160) in the pre-weaning period, and of the direct effect for the trait days to gain 240 kg (D240) in the post-weaning period, of animals of Nellore breed, born from 1965 to 2001 in the Northeast region of Brazil. The analyses were carried out using the MTDFREML software. For D160 the model included the direct and maternal genetic random effects and maternal permanent environmental effect, besides the fixed effects of contemporary group and the covariate age of dam at calving, assuming the covariance between maternal and direct effect equal to zero (sam=0). For D240, the same fixed effects were considered, however, just the direct genetic effect as random. The genetic trends were estimated by linear regression of the breeding values on year of birth of the animals. The direct and maternal heritabilities for D160, respectively, were 0.12 ± 0.01 and 0.07 ± 0.02. The direct heritability for D240 was 0.16 ± 0.02. The genetic trends of the direct effects were significant, with estimated values of -0.14 and -0.41 days/year for D160 and D240, respectively. The genetic trend of the maternal effect for D160 was significant and equal to -0.0037 days/year. The genetic trends were favorable, however, inferiors the potential gain.

Caracterização do ataque da broca dos frutos do pequizeiro

The extractivism of pequi fruits (Caryocar brasiliense Camb.) (Caryocaraceae) is an important option of income, food and employment for the populations living in the savannah regions all over Brazil. However, the natural supply of those fruit is endangered by a great deal of factors, among those stands out a serious pest, Carmenta sp. (Lepidoptera: Sesiidae) making them unsuitable for consumption. The present study aimed to know some characteristics of the responsible insect as well as the way of attacking pequi fruits, damage caused and characteristic symptoms. This work was performed through the analysis of previously collected pequi fruits, both on the plant and soil in the type savannah vegetation in Montes Claros county, Northern Minas and Itumirim, Southern Minas, in Minas Gerais State. In the former county were harvested fruits between 80 - 120 days after anthesis (DAA), while in the last one in two times, 45 and 90 DAA. In each county, collect time and site (plant or soil) were collected 50 fruits for analysis. The evaluated characteristics were: longitudinal and transversal diameter, percentage of damaged fruits, number of worm per fruit and number of chrysalides per fruit. After the analysis of those characteristics, the insects developmental stages were recorded and documented photographycally as to length, coloration and morphology as well as attack symptoms. From this work, we can conclude that the pequi fruit lepidoborer can provoke damage to yield higher than 50 %, destroying all the inside of the fruits. The youngest fruits are the most attacked, being commom to find a single worm in its inside.

Sobre a nomenclatura das espécies de cochonilhas-farinhentas do cafeeiro nos Estados de Minas Gerais e Espírito Santo

Root coffee (Coffea arabica L.) mealybugs (Hemiptera: Pseudococcidae) collected in Boa Esperanca, southern Minas Gerais State, were identified as Dysmicoccus texensis (Tinsley) (= bispinosus Beardsley) and these from aerial part collected in Castelo, State of the Espirito Santo, as Planococcus minor (Maskell). However, Brazilian literature mentions other mealybug species of coffee tree as Pseudococcus cryptus Hempel in roots and Planococcus citri (Risso) in the aerial part. Therefore, more than one mealybug species may be occurring in the roots as in aerial part of coffee trees, and the survey and taxonomic studies are necessary before setting a control program, specially biological control.

Distribuição espacial do ácaro Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) em cafeeiro (Coffea arabica L.)

The spatial distribution of the false spider mite Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae), vector of the ringspot virus, was studied in coffee plants (Coffea arabica L.), in order to assess the mite preferred sites. Samples were taken throughout leaves, branches and berries, from lower, medium and superior parts of the plants. The inner and the outer side of the plants were compared. All development stages of the mites were recorded. B. phoenicis was mostly found on the internal leaves, branches and berries, in the lower and medium parts of the plants. On the leaves, mites were localized mostly at the lower leaf surface, mainly next to the midrib. On the berries, eggs and mites were found mainly at the crown and peduncle. On the branches, they were found in the nodes and coat gap.

Parâmetros e tendência genética de peso de bovinos criados á pasto no Brasil

espanolParâmetros e tendencias geneticas para os pesos aos 120 (P120: n= 86 852), 205 (P205: n= 86 852), 365 (P365: n= 61 637) e 550 (P550: n= 36 187) dias de idade foram estimados para animais da raca Nelore criados a campo nas regioes Centro-Oeste e Sudeste no Brasil. Os dados sao provenientes da ABCZ/EMBRAPA e foram obtidos no periodo entre 1975 a 2001. Os parâmetros foram obtidos utilizando o programa MTDFREML, em analise unicaracteristica. Os efeitos fixos foram grupo de contemporâneos (combinacao de estacao (agua e seca), ano, sexo e fazenda) e a covariavel idade da vaca ao parto (linear e quadratico). Como efeito aleatorio utilizou- se o efeito aditivo direto, aditivo materno, e de ambiente permanente. As estimativas das variâncias geneticas, direta e materna, ambientais e fenotipicas e as covariâncias entre o efeito direto e materno foram 51,1; 17,9; 190,5; 280,4 e -12,0 para P120; 128,6; 47,2; 695,7; 932,4 e -25,9 para P205; 435,9; 32,2; 2934,0; 3604,9 e -27,4 para P365; 607,9; 177,7; 5637,7; 6602,5 e -117,6 para P550. Os valores de herdabilidades direta encontram-se na faixa de 0,09 a 0,18; herdabilidade materna variaram de 0,01 a 0,06, correlacao direta materna entre -0,23 a -0,36 e o efeito de ambiente permanente igual a 0,05 a 0,12. As estimativas das tendencias geneticas, direta materna, e ambientais no periodo de 1975 a 2001 foram 10,4; -1,6 e 18,4 kg para P120; 16,6; -2,8 e 23,0 kg P205; 21,7; -1,3 e 23,6 kg para P365; 25,5; -3,6 e -8,1 kg para P550, respectivamente. As tendencias geneticas diretas foram positivas e as maternas pequenas e nega- tivas. O desempenho materno tem influencia im- portante sobre os pesos aos 120 e 205 dias de idade e esse baixo valor obtido sugere que se deve considerar para este efeito nos programas de melhoramento, mesmo se tendo correlacao direta materna adversa. EnglishGenetic parameters and trends of weights were estimated for Nellore cattle from Central west and South East in Brazil. ABCZ/EMBRAPA provided weights (kg) at 120 (W120), 205 (W205), 365 (W365) and 540 (W540) for 86 852, 86 852, 61 637, 36 187 animals, respectively, from 1975 to 2001. Parameters were obtained using MTDFREML in single trait analyses. Fixed effects were contemporary group (dry or wet season), year, sex and farm and age of dam (linear and quadratic covariate). Random effects were direct and maternal genetic effects, their covariance, and the uncorrelated maternal permanent environmental effect. The analysis was restarted until twice the logarithms of the likelihoods changed no more than two decimal places. Estimates of direct and maternal genetic variances, direct-maternal covariance, and environmental and phenotypic variances were [51.1, 17.9, -12.0, 190.5 and 280.4] for W120; [128.6, 47.2, -25.9, 695.7 and 932.4] for W205; [435.9, 32.2, -27.4, 2934.0 and 3604.9] for W365; and [607.9, 177.7, -117.6, 5637.7 and 6602.5] for W540. Direct heritabilities ranged from 0.09 to 0.18, maternal heritabilities from 0.01 to 0.06, direct-maternal genetic correlations from -0.23 to -0.36, and permanent environmental effects from 0.05 to 0.12. Direct and maternal genetic and environmental trends from 1975 to 2001 were 10.4, -1.6 and 18.43 kg for W120; 16.6, -2.8; and 23.0 kg for W205; 21.7, -1.3 and 23.6 kg for W365, and, 25.5, -3.6, and -8.1 kg for W540, respectively. The direct genetic trends were positive and maternal trends were small. The importance of maternal performance for W120 and W205 suggests it should be considered in breeding programs although it has a low heritability and modestly adverse genetic correlation with direct genetic effects.

Genetic parameters for milk yield, lactation length and calving intervals of murrah buffaloes from brazil

The major objective of this study was to estimate heritability and genetic correlations between milk yield (MY) and calving interval (CI) and lactation length (LL) in Murrah buffaloes using Bayesian inference. The database used belongs to the genetic improvement program of four buffalo herds from Brazil. To obtain the estimates of variance and covariance, bivariate analyses were performed with the Gibbs sampler, using the program MTGSAM. The heritability coefficient estimates were 0.28, 0.03 and 0.15 for MY, CI and LL, respectively. The genetic correlations between MY and LL was moderate (0.48). However, the genetic correlation between MY and CI showed large HPD regions (highest posterior density interval). Milk yield was the only trait with clear potential for genetic improvement by direct mass selection. The genetic correlation between MY and LL indicates that indirect selection using milk yield is a potentially beneficial strategy. The interpretation of the estimated genetic correlation between MY and CI is difficult and could be spurious.