Fit and genetic parameters of the growth curve of Polled Nellore cattle / Ajuste e parâmetros genéticos da curva de crescimento em bovinos da raça Nelore Mocho

This study was undertaken to compare different non-linear models for fitting growth curves of Polled Nellore animals as well as to estimate genetic parameters for the components of the growth curve. The study involved body weight-age data of 6,717 Polled Nellore cattle from birth to 650 days of age, which belonged to the Brazilian Association of Zebu Breeders (ABCZ), corresponding to the period from 1980 to 2011. Four non-linear models (Brody, Bertalanffy, Logistic, and Gompertz) were fitted and compared by the adjusted coefficient of determination (R2adj), mean absolute deviation of residuals (MAD), root mean square error (RMSE), Akaike information criterion (AIC), and Bayesian information criterion (BIC). To estimate the genetic parameters and genetic values of asymptotic weight (A), integration constant (B), and maturation rate (K), the Bayesian inference method was adopted. The Brody model showed the lowest values of MAD, RMSE, AIC, and BIC and the highest R2adj. Heritability estimates for parameters A, B, and K were 0.11, 0.16, and 0.30, respectively, whereas genetic correlations were 0.01 (A-B), -0.91 (A-K), and 0.24 (B-K). The Brody model provided the best fit. The K parameter shows enough genetic variability for selection in the herd. Heavier animals in adulthood tend to exhibit lower growth rates. Despite the low heritability estimate of parameter A, there were genetic gains, indicating that selection is being efficient on asymptotic weight.(AU)

O objetivo deste estudo foi comparar diferentes modelos não lineares para o ajuste das curvas de crescimento de animais da raça Nelore Mocho e estimar os parâmetros genéticos para os componentes da curva de crescimento. Foram utilizados dados de peso corporal-idade do nascimento aos 650 dias de idades de 6.717 bovinos da raça Nelore Mocho, pertencentes à Associação Brasileira de Criadores de Zebu (ABCZ), referentes ao período de 1980 e 2011. Quatro modelos não lineares (Brody, Bertalanffy, Logístico e Gompertz) foram ajustados e comparados pelo coeficiente de determinação ajustado (R2adj), desvio médio absoluto dos resíduos (DMA), raiz quadrada do quadrado médio do resíduo (RMSE), critério de informação de Akaike (AIC) e o critério de informação bayesiano (BIC). Para estimativas dos parâmetros genéticos e valores genéticos do peso assintótico (A), constante de integração (B) e taxa de maturação (K), utilizou-se o método de inferência Bayesiana. O modelo Brody apresentou os menores valores de DMA, RMSE, AIC e BIC e o maior R2adj. As estimativas de herdabilidade foram 0,11; 0,16 e 0,30 para os parâmetros A, B e K, respectivamente, enquanto as correlações genéticas foram de 0,01 (A-B), -0,91 (A-K) e 0,24 (B-K). Constatou-se que o modelo Brody forneceu o melhor ajuste. O parâmetro K apresenta variabilidade genética suficiente para seleção no rebanho. Animais com maior peso na idade adulta tendem a apresentar menores taxas de crescimento. Apesar da baixa estimativa de herdabilidade do parâmetro A, observou-se ganhos genéticos, indicando que a seleção está sendo eficiente sobre o peso assintótico.(AU)

Comparative growth and performance of two generations of tilapia (Oreochromis niloticus)

The growth of generations of the Genomar Supreme Tilapia (GST) strain, specifically G20 and G25, was evaluated. Tilapias 8 g were reared in a recirculating aquaculture system with 0.25 m³ tanks, 80 fish m-³, with four replicates. During growth, eight fish from each tank were weighed and measured at day 1, 30, 60, 90, 120, 150, 180 and 210. Survival, weight gain, feed conversion and batch homogeneity were determined. Weight-age data were fit to Gompertz model. In addition, absolute and relative growth rates and weight and age at inflection were determined. Final weight showed 26.7% higher in G25 when compared to G20 (920.05 and 725.87 g, respectively). The feed conversion and homogeneity indexes were better in G25 than G20. The estimate of asymptotic weight was higher in G25 (1202.0 g) when compared to G20 (912.7 g). G20 presented smaller weight (335.76 g), age (108.87 days) and absolute growth rate (4.87 g day-1) when compared with G25 (442.19 g, 113.77 days and 6.41 g day-1). Carcass characteristics were similar, but G25 presented about 25% higher fillet weight than G20. After five years in the GST breeding program, results indicated that a sustained improvement of harvest weight was achieved, as well as 6 to 10% gain in performance by generation.(AU)

How to Make a Rodent Giant: Genomic Basis and Tradeoffs of Gigantism in the Capybara, the World's Largest Rodent.

Gigantism results when one lineage within a clade evolves extremely large body size relative to its small-bodied ancestors, a common phenomenon in animals. Theory predicts that the evolution of giants should be constrained by two tradeoffs. First, because body size is negatively correlated with population size, purifying selection is expected to be less efficient in species of large body size, leading to increased mutational load. Second, gigantism is achieved through generating a higher number of cells along with higher rates of cell proliferation, thus increasing the likelihood of cancer. To explore the genetic basis of gigantism in rodents and uncover genomic signatures of gigantism-related tradeoffs, we assembled a draft genome of the capybara (Hydrochoerus hydrochaeris), the world's largest living rodent. We found that the genome-wide ratio of nonsynonymous to synonymous mutations (ω) is elevated in the capybara relative to other rodents, likely caused by a generation-time effect and consistent with a nearly neutral model of molecular evolution. A genome-wide scan for adaptive protein evolution in the capybara highlighted several genes controlling postnatal bone growth regulation and musculoskeletal development, which are relevant to anatomical and developmental modifications for an increase in overall body size. Capybara-specific gene-family expansions included a putative novel anticancer adaptation that involves T-cell-mediated tumor suppression, offering a potential resolution to the increased cancer risk in this lineage. Our comparative genomic results uncovered the signature of an intragenomic conflict where the evolution of gigantism in the capybara involved selection on genes and pathways that are directly linked to cancer.

Referencias internacional y nacional, su uso en el estudio del crecimiento y la maduración física / International and national references, their use in the study of growth and physical maturation

Los factores genéticos y ambientales interactúan durante todo el crecimiento. La talla final adulta, el ritmo o tempo de crecimiento y maduración, así como la maduración sexual, esquelética y dental, tienen una transmisibilidad entre 41 y 71%. El estirón puberal ocurre un año antes en africanos que en europeos y los asiáticos son intermedios. Esta heterogeneidad puberal dificulta el uso de una referencia internacional en esta etapa, aunque su valor al permitir la comparabilidad entre poblaciones es indiscutible, así como el hecho que no todos los países pueden desarrollar sus propias referencias. En la Región Latinoamericana, Argentina, Cuba y Venezuela desarrollaron referencias hace muchos años y recientemente, Colombia, Ecuador y Perú. En Venezuela, se realizó el Estudio Nacional de Crecimiento y Desarrollo Humano (ENCDH) y el Estudio Longitudinal de Caracas (ELAMC) para establecer patrones de referencia, relevantes debido a la maduración más temprana y a las diferencias significativas en crecimiento y maduración con los anglosajones. Así mismo se elaboró el Atlas de Maduración Ósea del Venezolano y se han construido Curvas para uso Clínico integrando ambos estudios. Debido a la disparidad en el uso de referencias- internacionales y nacionalesse está planificando un estudio multicéntrico, denominado PRONNA, de la línea de investigación sobre Crecimiento y Desarrollo en Niños y Adolescentes (CDNNA) del Grupo Transición Alimentaria y Nutricional (grupo TAN) para la escogencia definitiva de las referencias a ser usadas(au)

Genetic and environmental factors interact during growth. Final height, tempo of growth, sexual, skeletal and dental maturation have between 41 and 71% heritability. The puberal spurt occurs one year earlier in Africans than in European descendants, Asiatic are intermediate. This pubertal heterogeneity difficult the use of an international reference during this period, although its importance in the comparability of prevalences is unique, as well as the fact that many countries are unable to develop their own references. In the Latin American Region, Argentina, Cuba and Venezuela have long--standing references, Colombia, Ecuador and Perú only recently. In Venezuela, due to the earlier maturation and differences from puberty onwards with anglosaxons, the National Growth and Development Study and the Caracas Longitudinal Study were developed in order to obtain growth charts. Both studies integrated for Clinical Use dual use charts: an Atlas for Bone Maturity Asessment is also available. Due to the multiple use of references (national as well as international) a multicenter national study-PRONNA- is being planned in order to decide which reference is most adequate. This is part of the Growth and Development Research line of study of TAN Group (Food and Nutritional Transition Group)(AU)

A new approach to the diagnosis of short stature.

Growth is the task of children. We review the normal process of linear growth from the fetus through adolescence and note that growth is the result of age- and gender-dependent interactions among key genetic, environmental, dietary, socioeconomic, developmental, behavioral, nutritional, metabolic, biochemical, and hormonal factors. We then define the wide range of normative data at each stage of growth and note that a pattern within this range is generally indicative of good general health and that growth significantly slower than this range may lead to growth faltering and subsequent short stature. Although not often emphasized, we detail how to properly measure infants and children because height velocity is usually determined from two height measurements (both relatively large values) to calculate the actual height velocity (a relatively much smaller number in comparison). Traditionally the physiology of growth has been taught from an endocrine-centric point-of-view. Here we review the hypothalamic-pituitary-end organ axes for the GH/IGF-1 and gonadal steroid hormones (hypothalamic-pituitary-gonadal axis), both during "mini"-puberty as well as at puberty. However, over the past few decades much more emphasis has been placed on the growth plate and its many interactions with the endocrine system but also with its own intrinsic physiology and gene mutations. These latter, whether individually (large effect size) or in combination with many others including endocrine system-based, may account in toto for meaningful differences in adult height. The clinical assessment of children with short stature includes medical, social and family history, physical exam and importantly proper interpretation of the growth curve. This analysis should lead to judicious use of screening laboratory and imaging tests depending on the pre-test probability (Bayesian inference) of a particular diagnosis in that child. In particular for those with no pathological features in the history and physical exam and a low, but normal height velocity, may lead only to a bone age exam and reevaluation (re-measurement), perhaps 6 months later. he next step depends on the comfort level of the primary care physician, the patient, and the parent; that is, whether to continue with the evaluation with more directed, more sophisticated testing, again based on Bayesian inference or to seek consultation with a subspecialist pediatrician based on the data obtained. This is not necessarily an endocrinologist. The newest area and the one most in flux is the role for genetic testing, given that growth is a complex process with large effect size for single genes but smaller effect sizes for multiple other genes which in the aggregate may be relevant to attained adult height. Genetics is a discipline that is rapidly changing, especially as the cost of exome or whole gene sequencing diminishes sharply. Within a decade it is quite likely that a genetic approach to the evaluation of children with short stature will become the standard, truncating the diagnostic odyssey and be cost effective as fewer biochemical and imaging studies are required to make a proper diagnosis.

Seleção e classificação multivariada de modelos não lineares para frangos de corte / Selection and classification of multivariate nonlinear models for broilers

Objetivou-se com este estudo utilizar a técnica de análise de agrupamento para classificar modelos de regressão não lineares usados para descrever a curva de crescimento de frangos de corte, levando em consideração os resultados de diferentes avaliadores de qualidade de ajuste. Para tanto, utilizaram-se dados de peso corporal e idade dos seguintes grupos genéticos de frangos de corte: Cobb500, Hubbard Flex e Ross308, de ambos os sexos, constituindo, assim, seis classes. Foram ajustados 10 modelos não lineares, cuja qualidade de ajuste foi medida pelo coeficiente de determinação ajustado, pelos critérios de informação de Akaike e bayesiano, pelo quadrado médio do erro e pelo índice assintótico. A análise de agrupamento indicou os modelos logístico, Michaelis-Menten, Michaelis-Menten modificado e von Bertalanffy como os mais adequados à descrição das curvas de crescimento das seis classes estudadas.

The aim of this study was to classify non-linear models used to describe the growth curve of broilers using the cluster analysis technique, taking into account the results of different measures of quality adjustment regression. For this purpose, we used data of body weight and age the following genetic groups of broilers: Cobb500, Hubbard Flex and Ross308, of both sexes, thus constituting six classes. Ten non-linear models were fitted, the quality of fit was measured by the adjusted coefficient of determination, Akaike information criteria and Bayesian, mean square error and index asymptotic. Cluster analysis indicated the Logistico, Michaelis Menten, Michaelis Menten Modificado and von Bertalanffy models as the most appropriate description of the growth curves for the six classes studied.

Seleção e classificação multivariada de modelos não lineares para frangos de corte / Selection and classification of multivariate nonlinear models for broilers

Objetivou-se com este estudo utilizar a técnica de análise de agrupamento para classificar modelos de regressão não lineares usados para descrever a curva de crescimento de frangos de corte, levando em consideração os resultados de diferentes avaliadores de qualidade de ajuste. Para tanto, utilizaram-se dados de peso corporal e idade dos seguintes grupos genéticos de frangos de corte: Cobb500, Hubbard Flex e Ross308, de ambos os sexos, constituindo, assim, seis classes. Foram ajustados 10 modelos não lineares, cuja qualidade de ajuste foi medida pelo coeficiente de determinação ajustado, pelos critérios de informação de Akaike e bayesiano, pelo quadrado médio do erro e pelo índice assintótico. A análise de agrupamento indicou os modelos logístico, Michaelis-Menten, Michaelis-Menten modificado e von Bertalanffy como os mais adequados à descrição das curvas de crescimento das seis classes estudadas.(AU)

The aim of this study was to classify non-linear models used to describe the growth curve of broilers using the cluster analysis technique, taking into account the results of different measures of quality adjustment regression. For this purpose, we used data of body weight and age the following genetic groups of broilers: Cobb500, Hubbard Flex and Ross308, of both sexes, thus constituting six classes. Ten non-linear models were fitted, the quality of fit was measured by the adjusted coefficient of determination, Akaike information criteria and Bayesian, mean square error and index asymptotic. Cluster analysis indicated the Logistico, Michaelis Menten, Michaelis Menten Modificado and von Bertalanffy models as the most appropriate description of the growth curves for the six classes studied.(AU)

Partial correction of the dwarf phenotype by non-viral transfer of the growth hormone gene in mice: Treatment age is critical.

Non-viral transfer of the growth hormone gene to different muscles of immunodeficient dwarf (lit/scid) mice is under study with the objective of improving phenotypic correction via this particular gene therapy approach. Plasmid DNA was administered into the exposed quadriceps or non-exposed tibialis cranialis muscle of lit/scid mice followed by electroporation, monitoring several growth parameters. In a 6-month bioassay, 50µg DNA were injected three times into the quadriceps muscle of 80-day old mice. A 50% weight increase, with a catch-up growth of 21%, together with a 16% increase for nose-to-tail and tail lengths (catch-up=19-21%) and a 24-28% increase for femur length (catch-up=53-60%), were obtained. mIGF1 serum levels were ~7-fold higher than the basal levels for untreated mice, but still ~2-fold lower than in non-dwarf scid mice. Since treatment age was found to be particularly important in a second bioassay utilizing 40-day old mice, these pubertal mice were compared in a third bioassay with adult (80-day old) mice, all treated twice with 50µg DNA injected into each tibialis cranialis muscle, via a less invasive approach. mIGF1 concentrations at the same level as co-aged scid mice were obtained 15days after administration in pubertal mice. Catch-up growth, based on femur length (77%), nose-to-tail (36%) and tail length (39%) increases was 40 to 95% higher than those obtained upon treating adult mice. These data pave the way for the development of more effective pre-clinical assays in pubertal dwarf mice for the treatment of GH deficiency via plasmid-DNA muscular administration.

Description of Santa Ines sheep growth using non-linear models selected by multivariate analysis / Descrição do crescimento de ovinos Santa Inês utilizando modelos não-lineares selecionados por análise multivariada

O objetivo deste estudo foi descrever o crescimento de ovinos Santa Inês utilizando modelos não-lineares selecionados por análise multivariada. Dezessete modelos não-lineares foram utilizados para descrever o crescimento de cordeiros do nascimento aos 210 dias de idade. Os modelos foram classificados por meio de análise multivariada utilizando o coeficiente de determinação ajustado, critério de informação de Akaike, critério de informação Bayesiano, erro quadrático médio de predição, coeficiente de determinação de predição, desvio médio absoluto dos resíduos e percentual de convergência como avaliadores da qualidade do ajuste. Os modelos Richards, Reynolds e Weibull não convergiram e os modelos Schnute, Meloun II, IV e VI, Gamito, Michaelis Menten e Michaelis Menten Modificado não apresentaram padrão de crescimento tradicional. Os modelos Mitscherlich, Gompertz, Logístico, Meloun I, III e V, Brody e Von Bertalanffy convergiram e foram utilizados na análise de agrupamento. Dentre os quatro clusters formados, o primeiro, composto pelos modelos Mitscherlich, Meloun I e Brody, apresentou os melhores valores para os critério de informação de Akaike e bayesiano. Os parâmetros da curva foram influenciados pelo sexo e o tipo de parto (P 0,05) e o ponto inflexão ocorreu aos 94 dias de idade.

The objective of this study was to describe the growth of Santa Ines sheep using nonlinear models selected by multivariate analysis. Seventeen nonlinear models were used to describe the growth of sheep from birth to 210 days of age. The models were classified by means of multivariate analysis using the adjusted coefficient of determination, the Akaike information criterion, the Bayesian information criterion, the mean squared error of prediction, the coefficient of determination, mean absolute deviation and percentage of convergence of prediction as evaluators of adjustment quality. The Richards, Reynolds and Weibull models did not converge and the Schnute, Meloun II, IV and VI, Gamito, Michaelis Menten and Modified Michaelis Menten models did not show any traditional growth pattern. Models Mitscherlich, Gompertz, Logistic, Meloun I, III and V, Brody and Von Bertalanffy converged and were used in grouping analysis. Of the four formed clusters formed, the first, composed by models Mitscherlich, Meloun I and Brody, showed the best values for all the evaluators considered. The curve parameters were influenced by gender and type of birth (P 0.05) and the inflection point occurred at 94 days of age. The Mitscherlich, Meloun I and Brody models are adequate and equivalent to describe the growth of Santa Ines sheep.

Description of Santa Ines sheep growth using non-linear models selected by multivariate analysis / Descrição do crescimento de ovinos Santa Inês utilizando modelos não-lineares selecionados por análise multivariada

O objetivo deste estudo foi descrever o crescimento de ovinos Santa Inês utilizando modelos não-lineares selecionados por análise multivariada. Dezessete modelos não-lineares foram utilizados para descrever o crescimento de cordeiros do nascimento aos 210 dias de idade. Os modelos foram classificados por meio de análise multivariada utilizando o coeficiente de determinação ajustado, critério de informação de Akaike, critério de informação Bayesiano, erro quadrático médio de predição, coeficiente de determinação de predição, desvio médio absoluto dos resíduos e percentual de convergência como avaliadores da qualidade do ajuste. Os modelos Richards, Reynolds e Weibull não convergiram e os modelos Schnute, Meloun II, IV e VI, Gamito, Michaelis Menten e Michaelis Menten Modificado não apresentaram padrão de crescimento tradicional. Os modelos Mitscherlich, Gompertz, Logístico, Meloun I, III e V, Brody e Von Bertalanffy convergiram e foram utilizados na análise de agrupamento. Dentre os quatro clusters formados, o primeiro, composto pelos modelos Mitscherlich, Meloun I e Brody, apresentou os melhores valores para os critério de informação de Akaike e bayesiano. Os parâmetros da curva foram influenciados pelo sexo e o tipo de parto (P 0,05) e o ponto inflexão ocorreu aos 94 dias de idade.(AU)

The objective of this study was to describe the growth of Santa Ines sheep using nonlinear models selected by multivariate analysis. Seventeen nonlinear models were used to describe the growth of sheep from birth to 210 days of age. The models were classified by means of multivariate analysis using the adjusted coefficient of determination, the Akaike information criterion, the Bayesian information criterion, the mean squared error of prediction, the coefficient of determination, mean absolute deviation and percentage of convergence of prediction as evaluators of adjustment quality. The Richards, Reynolds and Weibull models did not converge and the Schnute, Meloun II, IV and VI, Gamito, Michaelis Menten and Modified Michaelis Menten models did not show any traditional growth pattern. Models Mitscherlich, Gompertz, Logistic, Meloun I, III and V, Brody and Von Bertalanffy converged and were used in grouping analysis. Of the four formed clusters formed, the first, composed by models Mitscherlich, Meloun I and Brody, showed the best values for all the evaluators considered. The curve parameters were influenced by gender and type of birth (P 0.05) and the inflection point occurred at 94 days of age. The Mitscherlich, Meloun I and Brody models are adequate and equivalent to describe the growth of Santa Ines sheep.(AU)

Evolución clínica, radiológica y auxológica a largo plazo de 8 niños con displasia torácica asfixiante / Clinical, radiological and auxologic long-term evolution of 8 children with asphyxiating thoracic dysplasia

La displasia torácica asfixiante es una enfermedad infrecuente con compromiso multiorgánico y alta letalidad neonatal. Se presenta conbaja estatura, miembros cortos, tórax estrecho. Con la edad, hay mejoría respiratoria, pero aparición de compromiso renal, hepático, pancreático y/o retinal. Objetivo: Describir la evolución a largo plazo de 8 pacientes de un hospital de pediatría. Métodos: Se evaluaron retrospectivamente edad de diagnóstico, sexo, variables antropométricas, complicaciones y radiología. Resultados: Masculino/femenino, 6/2. Edad al momento del diagnóstico mediana: 2,54 años. Evolución: 8/8, compromiso respiratorio; 3/8, renal; 2/8, hepático; 1/8, oftalmológico; 1/8, cardíaco. Mediana de estatura al momento del diagnóstico: -1,76 DE; crecimiento posnatal y proporciones corporales, normales. Radiología: 8/8, tórax estrecho y braquifalangia en manos. 5/8, anomalías acetabulares. Discusión: Es recomendable un seguimiento para monitorear la función renal, hepática y ocular. El pediatra debería sospechar esta entidad ante un recién nacido con tórax estrecho y dificultad respiratoria.

Asphyxiating Thoracic Dysplasia is an uncommon condition with multiple organ afectation and high neonatal mortality. It presents with short stature, short extremities, narrow thorax. With growth, there is respiratory improvement, but emergence of renal, hepatic, pancreatic and/or retinal impairment. Objective: to describe the long-term evolution of 8 patients of a pediatric hospital. Methods: we retrospectively evaluated age at diagnosis, sex, anthropometric variables, complications and radiology. Results: male/female 6/2. Median age at diagnosis: 2.54 years. Evolution: 8/8 respiratory compromise, 3/8 kidney, liver 2/8, 1/8 ophthalmologic, cardiac 1/8. Median height at diagnosis -1.76 DS, normal postnatal growth and body proportions. Radiology: 8/8 narrow chest and brachyphalangia in hands. 5/8 acetabular abnormalities. Discussion: for surveillance it is recommended to monitor renal, liver and eye function. The pediatrician should suspect this entity in a newborn with narrow thorax and respiratory distress.

Estimação de parâmetros genéticos de características de crescimento pós desmama de bovinos mestiços Angus X Zebu / Estimation of genetic parameters for postweaning growth traits in crossbred Angus x Zebu cattle

Objetivou-se com o trabalho verificar o efeito da heterozigose individual no peso aos 365 dias (P365) e peso aos 550 dias (P550) de idade, assim como estimar a herdabilidade das características em estudo e os valores genéticos de animais de diferentes composições raciais envolvendo a raça Angus e zebuínos, a fim de observar a possibilidade do uso destas características como critérios de seleção em programas de cruzamento e melhoramento genético. Foram utilizados registros de 5.629 animais mestiços Angus x Zebu, nascidos no período de 1995 a 2004. Foram realizadas análises univariadas e bivariadas das características por meio de modelo animal e inferência bayesiana. Os efeitos incluídos no modelo foram grupo contemporâneo, heterozigose individual, idade do animal na pesagem, efeito aleatório genético direto do animal e resíduo. O tamanho da cadeia solicitado, bem como o período e o intervalo amostral, foram suficientes para obter convergência das estimativas a posteriori dos parâmetros genéticos. As estimativas de herdabilidade obtidas nas análises univariadas e na análise bivariada foram 0,38 e 0,30, e 0,32 e 0,30, respectivamente para P365 e P550. A estimativa de correlação genética entre as características foi 0,98. Ao comparar a classificação dos 10 melhores touros com base nos valores genéticos para P365 e P550, observou-se pequena diferença nas classificações para as características estudadas. O efeito da heterozigose tem importância nos cruzamentos e na obtenção de maiores pesos pós desmama, indicando que a utilização de animais com heterozigose individual máxima é vantajosa. As características P365 e P550 apresentaram-se como apropriados critérios de seleção, sugerindo que devam ser incluídas em programas de melhoramento de bovinos cruzados Angus x Zebu...(AU)

The objective of this study was to verify the effect of individual heterozygosity on weights at 365 (W365) and 550 (W550) days of age, and to estimate the heritability of these traits and the breeding values of animals of different breed compositions involving Angus and Zebu breeds in order to evaluate the possible use of these traits as selection criteria in crossbreeding and genetic improvement programs. Records from 5,629 crossbred Angus x Zebu animals born between 1995 and 2004 were used. Univariate and bivariate analyses of the traits were performed using an animal model and Bayesian inference. The effects included in the model were contemporary group, individual heterozygosis, age of animal at recording, and random direct genetic effect of the animal and residual. The size of the chain requested, as well as the burn-in period and thinning interval, was sufficient to obtain convergence of the posterior estimates of the genetic parameters. The heritability estimates obtained in univariate and bivariate analysis were 0.38 and 0.30 for W365 and 0.32 and 0.30 for W550, respectively. The genetic correlation between traits was 0.98. Comparison of the rank of the 10 best sires based on the breeding values for W365 and W550 showed a small difference between the traits studied. The effect of heterozygosity has importance for crossings and for obtaining higher postweaning weights, indicating that the use of animals with maximum individual heterozygosity is advantageous. W365 and W550 were found to be appropriate selection criteria and should be included in breeding programs of crossbred Angus x Zebu cattle...(AU)

Estimação de parâmetros genéticos de características de crescimento pós desmama de bovinos mestiços Angus X Zebu / Estimation of genetic parameters for postweaning growth traits in crossbred Angus x Zebu cattle

Objetivou-se com o trabalho verificar o efeito da heterozigose individual no peso aos 365 dias (P365) e peso aos 550 dias (P550) de idade, assim como estimar a herdabilidade das características em estudo e os valores genéticos de animais de diferentes composições raciais envolvendo a raça Angus e zebuínos, a fim de observar a possibilidade do uso destas características como critérios de seleção em programas de cruzamento e melhoramento genético. Foram utilizados registros de 5.629 animais mestiços Angus x Zebu, nascidos no período de 1995 a 2004. Foram realizadas análises univariadas e bivariadas das características por meio de modelo animal e inferência bayesiana. Os efeitos incluídos no modelo foram grupo contemporâneo, heterozigose individual, idade do animal na pesagem, efeito aleatório genético direto do animal e resíduo. O tamanho da cadeia solicitado, bem como o período e o intervalo amostral, foram suficientes para obter convergência das estimativas a posteriori dos parâmetros genéticos. As estimativas de herdabilidade obtidas nas análises univariadas e na análise bivariada foram 0,38 e 0,30, e 0,32 e 0,30, respectivamente para P365 e P550. A estimativa de correlação genética entre as características foi 0,98. Ao comparar a classificação dos 10 melhores touros com base nos valores genéticos para P365 e P550, observou-se pequena diferença nas classificações para as características estudadas. O efeito da heterozigose tem importância nos cruzamentos e na obtenção de maiores pesos pós desmama, indicando que a utilização de animais com heterozigose individual máxima é vantajosa. As características P365 e P550 apresentaram-se como apropriados critérios de seleção, sugerindo que devam ser incluídas em programas de melhoramento de bovinos cruzados Angus x Zebu...

The objective of this study was to verify the effect of individual heterozygosity on weights at 365 (W365) and 550 (W550) days of age, and to estimate the heritability of these traits and the breeding values of animals of different breed compositions involving Angus and Zebu breeds in order to evaluate the possible use of these traits as selection criteria in crossbreeding and genetic improvement programs. Records from 5,629 crossbred Angus x Zebu animals born between 1995 and 2004 were used. Univariate and bivariate analyses of the traits were performed using an animal model and Bayesian inference. The effects included in the model were contemporary group, individual heterozygosis, age of animal at recording, and random direct genetic effect of the animal and residual. The size of the chain requested, as well as the burn-in period and thinning interval, was sufficient to obtain convergence of the posterior estimates of the genetic parameters. The heritability estimates obtained in univariate and bivariate analysis were 0.38 and 0.30 for W365 and 0.32 and 0.30 for W550, respectively. The genetic correlation between traits was 0.98. Comparison of the rank of the 10 best sires based on the breeding values for W365 and W550 showed a small difference between the traits studied. The effect of heterozygosity has importance for crossings and for obtaining higher postweaning weights, indicating that the use of animals with maximum individual heterozygosity is advantageous. W365 and W550 were found to be appropriate selection criteria and should be included in breeding programs of crossbred Angus x Zebu cattle...

Growth, carcass traits and palatability: can the influence of the feeding regimes explain the variability found on those attributes in different Uruguayan genotypes?

It is well known what genetic and nutritional factors affect growth and meat quality, but there is less information related to interactive importance of them during the productive process. These systems are mainly based on rangelands affecting animal growth in early stages of life thus producing smaller cattle and reduced retail yield comparing with well grown calves. During the last ten years, Uruguayan livestock production systems have been intensified using improved pastures, concentrates and better genetic. The main breeds in Uruguay are Hereford, Angus and their crosses. These British breeds are under genetic evaluation programs which consider carcass trait parameters. It is important for beef industry to know if interactions between genotype and nutrition during growth and fattening phases are influencing production, efficiency, carcass weight and meat quality attributes. The aim of this article is to present information obtained under different feeding strategies during the post weaning and fattening and their influence on those attributes.

Contribution of polymorphisms in genes associated with craniofacial development to the risk of nonsyndromic cleft lip and/or palate in the Brazilian population.

BACKGROUND AND OBJECTIVE: Nonsyndromic cleft lip and/or palate (NSCL/P) is a complex disease associated with both genetic and environmental factors. One strategy for identifying of possible NSCL/P genetic causes is to evaluate polymorphic variants in genes involved in the craniofacial development. DESIGN: We carried out a case-control analysis of 13 single nucleotide polymorphisms in 9 genes related to craniofacial development, including TBX1, PVRL1, MID1, RUNX2, TP63, TGFß3, MSX1, MYH9 and JAG2, in 367 patients with NSCL/P and 413 unaffected controls from Brazil to determine their association with NSCL/P. RESULTS: Four out of 13 polymorphisms (rs28649236 and rs4819522 of TBX1, rs7940667 of PVRL1 and rs1057744 of JAG2) were presented in our population. Comparisons of allele and genotype frequencies revealed that the G variant allele and the AG/GG genotypes of TBX1 rs28649236 occurred in a frequency significantly higher in controls than in the NSCL/P group (OR: 0.41; 95% CI: 0.25-0.67; p=0.0002). The frequencies of rs4819522, rs7940667 and rs1057744 minor alleles and genotypes were similar between control and NSCL/P group, without significant differences. No significant associations among cleft types and polymorphisms were observed. CONCLUSION: The study suggests for the first time evidences to an association of the G allele of TBX1 rs28649236 polymorphism and NSCL/P.

Cotton response to mepiquat chloride and temperature

Gibberellin inhibitor growth regulators are used for cotton (Gossypium hirsutum L.) canopy manipulation to avoid excess growth and yield losses. However, under temperatures below or over the optimum for cotton production the effect of mepiquat chloride (MC) has not always been significant. In this experiment, cotton plants were grown in growth chambers to study the response to MC as affected by temperature and to determine if an increase in dose could overcome the temperature effects. Mepiquat chloride was applied at rates of 0, 15 and 30 g ai ha-1 at the pinhead square stage. Plants were then grown under three temperature regimes: 25/15 °C, 32/22 °C, and 39/29 °C (day/night temperatures) for 51 days. Higher temperatures increased plant height, reproductive branches, fruit number, fruit abscission, and photosynthesis per unit area, but decreased leaf area and chlorophyll. The largest effect of MC on plant height was observed when the daily temperature was 32 °C, with nights of 22 °C, which was also best for plant growth. High temperatures not only decreased the effectiveness of MC on plant height control, but also caused lower dry matter and fruit number per plant. Low temperatures (25/15 ºC) decreased cotton growth and fruit retention, but a higher concentration of MC was required per unit of growth reduction as compared with 32/22 ºC. At high temperatures, the rate of MC to be applied must be disproportionately increased, because either plant growth is impaired by high temperature lessening the effect of MC, or degradation of MC within the plant is too rapid.

Cotton response to mepiquat chloride and temperature

Gibberellin inhibitor growth regulators are used for cotton (Gossypium hirsutum L.) canopy manipulation to avoid excess growth and yield losses. However, under temperatures below or over the optimum for cotton production the effect of mepiquat chloride (MC) has not always been significant. In this experiment, cotton plants were grown in growth chambers to study the response to MC as affected by temperature and to determine if an increase in dose could overcome the temperature effects. Mepiquat chloride was applied at rates of 0, 15 and 30 g ai ha-1 at the pinhead square stage. Plants were then grown under three temperature regimes: 25/15 °C, 32/22 °C, and 39/29 °C (day/night temperatures) for 51 days. Higher temperatures increased plant height, reproductive branches, fruit number, fruit abscission, and photosynthesis per unit area, but decreased leaf area and chlorophyll. The largest effect of MC on plant height was observed when the daily temperature was 32 °C, with nights of 22 °C, which was also best for plant growth. High temperatures not only decreased the effectiveness of MC on plant height control, but also caused lower dry matter and fruit number per plant. Low temperatures (25/15 ºC) decreased cotton growth and fruit retention, but a higher concentration of MC was required per unit of growth reduction as compared with 32/22 ºC. At high temperatures, the rate of MC to be applied must be disproportionately increased, because either plant growth is impaired by high temperature lessening the effect of MC, or degradation of MC within the plant is too rapid.(AU)

Desnutrição protéico-calórica e deficiência de ferro na gestação da rata jovem: repercussões sobre o crescimento e o desenvolvimento materno, fetal e da placenta e sobre alguns parâmetros hematológicos maternos / Protein-energy malnutrition and iron deficiency in pregnancy in rats young: effects on growth and development of maternal and fetal placenta and maternal blood parameters of some

Ratas jovens, submetidas durante os primeiros 17 dias de gestação a dieta contendo 6% de proteina e 70mg de ferro, mostraram: Ganho de peso corporal mais intenso a partir do 13 dia de gestação do que o apresentado pelas desnutridas não gravidas porém reduzido em relação ao de ratas controle gravidas

Suplementação energético-proteica-mineral no desenvolvimento corporal e no comportamento ingestivo de novilhas mestiças Gir x Holandês em pastejo durante a época da seca / Energy-protein supplementation and mineral body development and ingestive behavior of crossbed Holstein x Gir heifer’s grazing in dry season

Objetivou-se avaliar o efeito de dois níveis de suplementação com fontes de minerais inorgânico e orgânico, na época da seca, sobre o crescimento e o comportamento ingestivo de novilhas mestiças Gir x Holandês, com idade média de 19,4 ± 1,94 meses e peso corporal médio inicial de 307,75 ± 25,0 kg, distribuídas em um delineamento experimental inteiramente casualizado com esquema fatorial 2 x 2 (minerais x níveis) com cinco repetições por tratamento. As novilhas permaneceram em pastagem de Brachiaria brizantha (Hochst. ex. A. Rich.) Stapf. cv. Marandu, manejadas em sistema intermitente e, como tratamento, utilizou-se suplementação com fontes de minerais inorgânicos ou orgânicos e dois níveis de fornecimento (2,5 e 5,0 g/kg do peso corporal). O desenvolvimento corporal das novilhas que receberam suplemento, nos dois níveis, com fontes de minerais inorgânicos não diferiu daquelas que receberam fontes de minerais orgânicos. No entanto, as novilhas suplementadas com 5,0 g/kg do peso corporal apresentaram maior ganho médio diário (0,476 kg/animal) em comparação àquelas suplementadas com 2,5 g/kg do peso corporal (0,368 kg/animal). O desempenho de novilhas leiteiras recriadas a pasto foi semelhante quando suplementadas com fontes minerais inorgânicos ou orgânicos.

The objective was to evaluate the effect of two levels of supplementation with sources of inorganic and organic minerals in the dry season on growth and ingestive behavior of crossbred Gir x Holstein, with an average of 19.4 ± 1.94 months and 307.75 ± 25.0 kg body weight , allotted to an completely randomized design with scheme factorial 2 x 2 (mineral x levels) with five replicates per treatment. The heifers remained on Brachiaria brizantha (Hochst. ex. A. Rich.) Stapf. cv. Marandu managed in a rotational grazing system, and treatments were supplementation sources of inorganic and organic minerals and two levels of 2.5 and 5.0 g/kg of body weight. The growth of heifers that received supplement in two levels with sources of inorganic minerals did not differ (P>0.05) from those that received sources of organic minerals. However, the heifers receiving 5.0 g/kg of body weight had higher average daily gain (0.476 kg/animal) compared with those receiving 2.5 g/kg of body weight (0.368 kg/animal). The performance of dairy heifers rearing pasture was similar when supplemented with organic or inorganic mineral sources.