Models for genetic evaluation of Nelore cattle mature body weight

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Genetic associations of conformation, finishing precocity and muscling visual scores with mature weight in Nelore cattle

Were estimate (co)variance and genetic associations between conformation, finishing precocity and muscling visual scores measured at weaning (SCW, SFW and SMW, respectively) and yearling (SCY. SFY and SMY, respectively) with mature weight (MW) in Nelore cows, in order to predict the possible changes that inclusion of visual scores in beef cattle selection indices would bring to female mature weight. The data set contained records of 36,757 females, born between 1993 and 2006, belonging to the Jacarezinho cattle raising farm. (Co)variance components were estimated by bivariate animal models using Bayesian inference method through Gibbs sampling, assuming a linear model for MW and a nonlinear (threshold) model for conformation, finishing precocity and muscling visual scores. The first 10,000 rounds were considered as the burn-in period and discarded. The posterior means of direct heritability distributions were: 0.16 +/- 0.02 (SCW); 0.20 +/- 0.02 (SFW); 0.19 +/- 0.02 (SMW); 0.24 +/- 0.02 (SCY); 0.31 +/- 0.02 (SFY); 0.32 +/- 0.02 (SMY) and 0.46 +/- 0.04 (MW). Estimates of genetic correlations between visual scores and MW were positive and moderate, ranging from 0.27 +/- 0.06 to 0.36 +/- 0.04. Visual scores and MW should respond favorably to direct selection. Mature weight can be used in Nelore breeding programs designed to monitor the cows' size. Selection of animals with higher conformation, finishing precocity and muscling scores, especially at yearling, should promote an increase in cows' mature weight. (c) 2010 Elsevier B.V. All rights reserved.

Random regression analyses using B-splines functions to model growth from birth to adult age in Canchim cattle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estimativas de parâmetros genéticos e de ganhos direto e indireto à seleção para características de crescimento de machos e fêmeas da raça Canchim

Neste trabalho, objetivou-se estimar as herdabilidades e as correlações genéticas entre os pesos ao nascimento (PN), à desmama (P240), ao ano (P365) e ao sobreano (P550), os ganhos de peso do nascimento à desmama (GND) e do nascimento ao sobreano (GN18), o número de dias para ganhar 175 kg do nascimento à desmama (D175) e para ganhar 450 kg do nascimento ao abate (D450) de machos e fêmeas, o peso adulto (PAD) de fêmeas em um rebanho da raça Canchim visando à definição de critérios de seleção. Foram realizadas análises unicaracteres e bicaracteres pelo método da máxima verossimilhança restrita livre de derivadas utilizando-se modelos estatísticos que incluíram os efeitos fixos de ano e mês de nascimento, sexo do animal, ano e mês do parto, idade do animal ao parto e idade da mãe como covariável (efeitos linear e quadrático), além dos efeitos aleatórios aditivo direto e materno, de ambiente permanente e residual, dependendo da característica. As estimativas de herdabilidade obtidas pelas análises unicaracteres foram iguais a 0,41 (PN), 0,28 (P240), 0,38 (P365), 0,28 (P550), 0,26 (GND), 0,30 (GN18), 0,23 (D175), 0,23 (D450) e 0,48 (PAD), enquanto as estimativas de correlação genética obtidas por análises bicaracteres variaram de 0,28 a 0,97 entre os pesos, de 0,11 a 0,97 entre pesos e ganhos de peso, de 0,00 a -0,98 entre pesos e dias para atingir determinado peso, e de -0,63 a -0,98 entre os ganhos de peso e dias para atingir determinado peso e iguais a 0,69 para GND e GN18 e 0,76 para D175 e D450. Estas estimativas sugerem a possibilidade de se obter progresso genético pela seleção para todas as características estudadas e que a seleção para qualquer uma delas deverá provocar mudanças nas outras.

Herdabilidades e correlações entre pesos do nascimento à idade adulta em rebanhos da raça Nelore

Dados de 19.458 animais da raça Nelore, nascidos entre 1975 e 2002 e pertencentes a oito fazendas participantes do Programa de Melhoramento Genético da Raça Nelore (PMGRN), foram utilizados para estimar componentes de covariância, herdabilidade e correlações genéticas dos pesos ao nascimento, à desmama, ao sobreano e aos 2, 3 e 5 anos de idade. Utilizou-se o método da máxima verossimilhança restrita, em análises uni, bi e multicaracterísticas, com modelos que incluíram o efeito genético aditivo direto, como aleatório, além dos efeitos fixos de grupo de contemporâneos e os efeitos linear e quadrático da idade do animal à pesagem (com exceção do modelo para peso ao nascer) e da idade da mãe ao parto. O efeito aleatório de ambiente permanente materno também foi incluído nos modelos de análise do peso ao nascer, peso à desmama e peso ao sobreano e o efeito aleatório genético materno somente no modelo do peso à desmama. As herdabilidades estimadas em análise multicaracterística para os pesos ao nascer, à desmama, ao sobreano, aos 2, 3 e aos 5 anos de idade foram 0,25; 0,33; 0,34; 0,32; 0,33 e 0,35, respectivamente. As correlações genéticas estimadas entre os pesos foram positivas e de moderadas a altas magnitudes e tenderam a diminuir com o aumento da distância entre as pesagens, o que indica que a seleção para peso em qualquer idade deverá promover mudança genética nos pesos nas demais idades, inclusive no peso adulto de fêmeas da raça Nelore. As estimativas de herdabilidade obtidas na análise multicaracterística foram superiores, sobretudo para os pesos aos 3 e aos 5 anos de idade, o que sugere melhor partição das variâncias genética e de ambiente em comparação às análises uni e bicaracterísticas, porém a alta demanda de recursos computacionais em análises de muitas características pode ainda dificultar o uso dessas análises em grandes bancos de dados.

Genetic parameters and relationships of heifer pregnancy and age at first calving with weight gain, yearling and mature weight in Nelore cattle

The objectives of the current study were to investigate the additive genetic associations between heifer pregnancy at 16 months of age (HP16) and age at first calving (AFC) with weight gain from birth to weaning (WG), yearling weight (YW) and mature weight (MW), in order to verify the possibility of using the traits measured directly in females as selection criteria for the genetic improvement of sexual precocity in Nelore cattle. (Co)variance components were estimated by Bayesian inference using a linear animal model for AFC, WG, YW and MW and a nonlinear (threshold) animal model for HP16. The posterior means of direct heritability estimates were: 0.45 +/- 0.02; 0.10 +/- 0.01; 023 +/- 0.02; 0.36 +/- 0.01 and 0.39 +/- 0.04, for HP16, AFC, WG, YW and MW, respectively. Maternal heritability estimate for WG was 0.07 +/- 0.01. Genetic correlations estimated between HP16 and WG, YW and MW were 0.19 +/- 0.04; 0.25 +/- 0.06 and 0.14 +/- 0.05, respectively. The genetic correlations of AFC with WG, YW and MW were low to moderate and negative, with values of -0.18 +/- 0.06; -0.22 +/- 0.05 and -0.12 +/- 0.05, respectively. The high heritability estimated for HP16 suggests that this trait seem to be a better selection criterion for females sexual precocity than AFC. Long-term selection for animals that are heavier at young ages tends to improve the heifers sexual precocity evaluated by HP16 or AFC. Predicted breeding values for HP16 can be used to select bulls and it can lead to an improvement in sexual precocity. The inclusion of HP16 in a selection index will result in small or no response for females mature weight. (C) 2011 Elsevier B.V. All rights reserved.

Breeding value accuracy estimates for growth traits using random regression and multi-trait models in Nelore cattle

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

Random regression analyses using B-spline functions to model growth of Nellore cattle

The objective of this study was to estimate (co)variance components using random regression on B-spline functions to weight records obtained from birth to adulthood. A total of 82 064 weight records of 8145 females obtained from the data bank of the Nellore Breeding Program (PMGRN/Nellore Brazil) which started in 1987, were used. The models included direct additive and maternal genetic effects and animal and maternal permanent environmental effects as random. Contemporary group and dam age at calving (linear and quadratic effect) were included as fixed effects, and orthogonal Legendre polynomials of age (cubic regression) were considered as random covariate. The random effects were modeled using B-spline functions considering linear, quadratic and cubic polynomials for each individual segment. Residual variances were grouped in five age classes. Direct additive genetic and animal permanent environmental effects were modeled using up to seven knots (six segments). A single segment with two knots at the end points of the curve was used for the estimation of maternal genetic and maternal permanent environmental effects. A total of 15 models were studied, with the number of parameters ranging from 17 to 81. The models that used B-splines were compared with multi-trait analyses with nine weight traits and to a random regression model that used orthogonal Legendre polynomials. A model fitting quadratic B-splines, with four knots or three segments for direct additive genetic effect and animal permanent environmental effect and two knots for maternal additive genetic effect and maternal permanent environmental effect, was the most appropriate and parsimonious model to describe the covariance structure of the data. Selection for higher weight, such as at young ages, should be performed taking into account an increase in mature cow weight. Particularly, this is important in most of Nellore beef cattle production systems, where the cow herd is maintained on range conditions. There is limited modification of the growth curve of Nellore cattle with respect to the aim of selecting them for rapid growth at young ages while maintaining constant adult weight.

Determination of fiber length and juvenile and mature wood zones from Hevea brasiliensis trees grown in Brazil

The aim of this study was to verify the average fiber length and the juvenile and mature wood zones from Hevea brasiliensis proveniences from a reforestation area in São Paulo, Brazil. For this purpose, five Hevea brasiliensis trees were randomly collected from a 50-year-old plantation, located in Balsamo, São Paulo, Brazil. The trees were cut and five flat sawn boards were obtained. The juvenile and mature wood zones were determined by fiber length measurement from the pith to the bark. The results showed that: (a) the juvenile wood of this species occurred approx. between 40 and 55 mm, from the pith, and from this point forward, the mature wood zone was found; (b) there was a significant difference between the average fiber length of juvenile wood (1.26 mm) and mature wood (1.51 mm).

Analysis of land use and occupancy in permanent preservation areas according to the hydrography of Ribeirão Água Fria - Bofete, SP - Brazil

Os conflitos de uso são determinados pelas ocupações inadequadas do solo, como é o caso de ocupação do solo dentro de áreas de preservação permanente. O presente trabalho teve como objetivos determinar as classes de uso do solo e se há conflitos dentro de áreas de preservação permanente ao longo da rede de drenagem da microbacia do Ribeirão Água Fria, município de Bofete (SP). Situa-se geograficamente entre as coordenadas: 48°09'30 a 48°18'30 de longitude WGr., 22°58'30 a 23°04'30 de latitude sul com uma área de 15.242,84 ha. O mapa de uso do solo foi elaborado por meio da interpretação diretamente na tela do computador de imagem digital de satélite. Nos dados orbitais, a área de estudo está inserida no quadrante A, da imagem TM/Landsat-5, órbita 220, ponto 76, passagem de 8/09/2007. O Sistema de Informação Geográfica empregado foi o Cartalinx. As áreas de conflito da microbacia foram obtidas a partir do cruzamento entre os mapas de uso do solo e de APPs. Os resultados permitiram concluir que mais da metade da área (51,09%) está ocupada por pastagens, reflexo de solos arenosos e de baixa fertilidade. Constatou-se, ainda, que apesar de quase metade da microbacia estar coberta com algum tipo de vegetação (48,78% de mata natural/reflorestamento), possui aproximadamente um terço das áreas de preservação permanente utilizadas inadequadamente por pastagens (88,15%), reflorestamento (10,42%) e solo exposto (1,43%), totalizando 343,07 ha de áreas conflitantes em um total de 993,26 ha de APPs.

Physical and chemical changes in juvenile and mature woods of Pinus elliottii var. elliottii by thermal modification

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

Sewage sludge levels on the development and nutrition of sunflower plants

This study aimed to evaluate the effect of substituting chemical nitrogen (N) fertilization for equivalent N levels from sewage sludge of Wastewater Treatment Plant (WTP) on sunflower plant development. Nutrient levels in physiologically mature leaves and seeds, besides nutrient exportation during a 130-day assay, were also assessed. The experiment was carried out in 100 m(2) permanent plots at Sao Manuel Farm, which belongs to School of Agronomical Sciences, São Paulo State University-UNESP, Botncatu, São Paulo State, Brazil. The farm is located in the municipality of Sao Manuel, São Paulo State. Experimental design was in randomized blocks including 5 treatments and 5 replicates. Treatments were: T1 - chemical N fertilization according to the recommendation for the culture; T2 - 50% N from sewage sludge and 50% N from chemical fertilization; T3 - 100% N from sewage sludge; T4 - 150% N from sewage sludge; T5 - 200% N from sewage sludge. For all treatments, equal amounts of P and K fertilization were applied. Treatments differed for plant height from 21 to 64 days, stern diameter from 28 to 57 days, and leaf number from 21 to 38 days. Seed nutrient levels slightly varied; however, the quantities of exported N, P, Mg, Fe and Zn varied as sewage sludge levels increased.

Tungsten permanent chemical modifier for fast estimation of Se contents in soil by graphite furnace atomic absorption spectrometry

A tungsten carbide coating on the integrated platform of a transversely heated graphite atomizer was used as a modifier for the direct determination of Se in soil extracts by graphite furnace atomic absorption spectrometry. Diethylenetriaminepentaacetic acid (0.0050 mol L-1) plus ammonium hydrogencarbonate (1.0 mol L-1) extracted predominantly available inorganic selenate from soil. The formation of a large amount of carbonaceous residue inside the atomizer was avoided with a first pyrolysis step at 600 degreesC assisted by air during 30 s. For 20 muL of soil extracts delivered to the atomizer and calibration by matrix matching, an analytical curve (10.0-100 mug of L-1) with good linear correlation (r = 0.999) between integrated absorbance and analyte concentration was established. The characteristic mass was similar to63 pg of Se, and the lifetime of the tube was similar to750 firings. The limit of detection was 1.6 mug L-1, and the relative standard deviations (n = 12) were typically <4% for a soil extract containing 50 mug of L-1. The accuracy of the determination of Se was checked for soil samples by means of addition/recovery tests. Recovery data of Se added to four enriched soil samples varied from 80 to 90% and indicated an accurate method.

Avaliação de lesões brancas de cáries: um estudo de prognóstico

Objective: The aim of the present study is to assess the current situation of white enamel lesions on vestibular surfaces of permanent upper incisors, diagnosed 6 years ago, without clinical intervention. Methods: A prospective study reassessed 53 students of both sexes, aged between 13 and 18 years old, all attending the public school system in Natal, Brazil. Data collection was performed by duly calibrated examiners, and a clinical chart consisting of demographic data on dental caries, oral hygiene, and gingival condition was prepared. A tactile-visual examination was conducted using a clinical mirror and periodontal probe. Data compilation and analysis were carried out using a SPSS software. In this analysis the chi-squared test was used for qualitative independent variables. To identify the net effect of treatment, multiple logistic analysis with forward stepwise model selection was performed. Results: The final sample was composed of 106 lesions in the 53 individuals, with mean age of 15.02 years, visible plaque index (VPI) of 23.34%, and gingival blood indices (GBI) of 25.92%. A statistically significant relationship (p = 0.003) was found between initial DMFS and prognosis of white enamel lesion. Conclusions: We observed that past caries experience and dental plaque were the main predictive factors for negative lesion outcomes, demonstrating the need for oral hygiene control through continuing preventive measures

Recovering the function and esthetics of fractured teeth using several restorative cosmetic approaches. Three clinical cases

The teeth most commonly affected by trauma are the maxillary central incisors. The most frequent types of traumatic dental injuries to permanent teeth are enamel fractures, enamel and dentine fractures, and enamel and dentine fractures with pulp involvement. This article describes three clinical cases with different levels of traumatized maxillary incisors and several cosmetic approaches for recovery of the esthetics and the masticatory function, as well as the social/psychological aspects of treatment. All cases involved young adult men. The three clinical cases involve dentin and enamel fractures, dentin and enamel fractures with pulp exposure, and dentin and enamel fractures with pulp exposure associated with root fracture. The cosmetic treatments used to resolve fractures were direct composite resin by layering technique, indirect all-ceramic restorations (laminate veneer and ceramic crowns over the teeth), and immediate implant after extraction followed by immediate loading (ceramic abutments with ceramic crown over implant). In all three cases, excellent functional and esthetic results were achieved by use of these treatment modalities. The patients were very satisfied with the results.