RESUMO

The use of mixed nonlinear models reduces the residual variance by including random effects, thereby improving the estimates in growth curves. Therefore, we tested distinct mixed nonlinear models (Richards, Brody, Gompertz, Logistic, and Von Bertalanffy) to model the growth curves of Zebu cattle herds raised on pasture in Brazil. In addition, we evaluated the diversity among breeds using hierarchical cluster multivariate analysis (full linkage) based on asymptotic weight (A), maturity rate (K), absolute growth rate (AGR), and absolute maturity rate (AMR) adjusted to 205, 365, 550, and 730 days of age. Body weight data from 311,834 males and females of Guzerat, Nellore, Tabapuã, and Polled Nellore breeds provided by the Brazilian Association of Zebu Breeders were used. The Brody model considering breed-sex fixed and animal random effects was the most suitable to describe the growth in the four breeds. The Guzerat and Tabapuã males showed increased precocity (higher K values) when compared to polled Nellore and Nellore males, which were characterized by higher A and AMR values. Females were more precocious than males (high K and low A values), particularly within Tabapuã and Guzerat breeds, respectively. Regardless of sex, the highest AGR values were observed from weaning up to 2 years of age in Tabapuã and Guzerat breeds. The cluster analyses revealed two groups: (1) Polled Nellore and Nellore males with high A, AGR_205, AGR_365, AGR_550, and AGR_730 values, represented by large adult animals, and (2) males and females of Guzerat and Tabapuã, characterized as animals of increased precocity. A subgroup encompassing males of Guzerat and Tabapuã was also observed, with intermediate values ​​for all parameters. This information is useful to help breeders and producers in strategies for feeding management and defining the most precocious beef cattle breed to increase the economic gains in pasture-based raising systems.

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RESUMO

This study investigated phenotypic differences of zebu females from four breeds using variables of growth, feed efficiency, and age at first calving. Weights throughout the life were recorded, and a growth curve was fitted using the Gompertz model. The growth was also evaluated at standardized ages (205, 365, and 550 days) using the body weight and the total and daily weight gains. The Kleiber index and age at first calving were used as measures of feed efficiency and sexual precocity, respectively, totaling 25 variables. New variables were created using the factor analysis and used in new multivariate analyzes. Only six factors explained 95.41% of the total variance and were used for the subsequent analyses. The factors were defined as maturity, precocity, feed efficiency postweaning, feed efficiency post 1 year of age, puberty, and birth weight. There were differences between breeds according to the multivariate analysis of variance. Each breed appeared in a quadrant on the Biplot graph, showing relationship with different factors, demonstrating the diversity of zebu females. There is a difference in growth, feed efficiency, and sexual precocity in Brazilian zebu females, allowing the identification of potentials of the animals and help breeders and decision-makers.

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RESUMO

Estimation methods are routinely used to determine the body weight of a horse when a scale is not available. However, it is important to evaluate the accuracy and reliability of these predictions since nutritional management and drug dosage, among others, require knowledge of the animals weight. The objective of this study was to evaluate the accuracy and reliability of estimated weights of horses using two prediction models, and to discuss the effect of the predictions on animal management. Seventy-one adult male animals (40 mules and 31 horses) were weighed on a precision scale (control weight). Chest circumference and body length were measured and used to estimate body weight using the two models. Accuracy was evaluated by analysis of fit indices, comparison of squared prediction errors, delta Akaikes information criterion, and decomposition of the mean squared error of prediction. For economic evaluation, three production scenarios were established: simple (worming + forage), traditional (worming + forage + concentrate mixture), and traditional with supplementation (worming + forage + concentrate mixture + supplementation). Economic values were collected through a pricing survey carried out in the Midwest region of Brazil and converted to US dollars. Percent differences in costs were evaluated using Fishers exact test. The most suitable model for the morphometric profile of the animals was that using a combination of chest circumference and body length. The differences in economic values between production scenarios were significant (P<0.05). Losses using the inadequate model are 10% higher compared to control; thus, in a facility with 20 equids that uses this model, the losses are ≈ US$ 10,000/year. When investment in a scale is not possible, it is fundamental to evaluate which model is more compatible with the body biotype of the herd since all types of management that depend on the body weight of the animals may result in significant economic losses.(AU)

Estimativas para determinar o peso corporal de um equino são rotineiramente usadas quando uma balança não está disponível. Todavia, é fundamental realizar um diagnóstico da acurácia e confiabilidade das predições destes estimadores, pois o manejo nutricional, dosificação de fármacos, entre outros, exigem o conhecimento do peso. Assim, objetivou-se avaliar a acurácia e confiabilidade de predições de peso estimado de equídeos utilizando dois modelos de cálculos e discutir o reflexo das predições no manejo dos animais. Foram pesados 71 equídeos machos (40 Muares e 31 Equinos) com idade adulta, em balança de precisão (peso controle). Medidas de perímetro torácico e comprimento corporal foram realizadas e utilizadas para estimar o peso corporal usando os modelos. A acurácia foi avaliada via análise do índice de adequação, comparação entre o quadrado do erro de predição, critério de informação Delta Akaike's e decomposição do erro quadrático médio da predição. Para avaliação econômica, criaram-se três cenários de produção: simples (vermifugação + volumoso), tradicional (vermifugação + volumoso + concentrado) e tradicional com suplementação (vermifugação + volumoso + concentrado + suplementação). Valores econômicos foram verificados em pesquisa de preço na região Centro Oeste do Brasil e convertidos em dólar. Avaliou-se as diferenças de percentagem dos custos utilizando teste de Fisher. O modelo mais adequado para o perfil morfométrico dos animais foi o que usa combinação entre perímetro torácico e comprimento corporal. Foram significativas (P<0,05) as diferenças para os valores econômicos nos cenários de produção. Prejuízos usando o modelo inadequado são 10% superiores em relação ao controle, assim em um estabelecimento com 20 equídeos que usa este modelo, os prejuízos são ≈ 10 mil dólares/ano. Na ausência da balança, é fundamental avaliar qual modelo de cálculo será mais compatível com biotipo corporal do rebanho, pois todo tipo de manejo que depende do peso corporal dos animais, pode gerar prejuízos econômicos significativos.(AU)

Assuntos

RESUMO

The selection of animals with lower production costs can be achieved by using feed efficiency and growth curve information. Kleiber ratio (KR) is an alternative option for discriminating against the animals that have the greatest weight gain about their final weight. Alternative feed efficiency and growth curves for ostriches of the African Black (AB) and Red Neck (RN) breeds and their crossbreeds (CB) were investigated using KR and Gompertz equation. Univariate and multivariate analyses were used. The highest adult weight was identified in the RN and CB. AB was more precocious than the RN and CB individuals. Only AB animals reached 75% of their mature weight at one year of age. At 180 days, AB showed better KR. AB was different from the others, mainly for KR at 90 days and 180 days. Considering multivariate analysis, AB animals were different from the others, regardless of sex, mainly for KR at 90 days and KR at 180 days. Other subgroups separated the animals by sex. In a market preferring animals of minor structure (smaller cuts) and greater precocity, it would be suitable to opt for AB. When animals with greater body structure (larger cuts) are desired, males RN and CR is the best option, however, it will be slaughtered with greater age and lower value for KR (may generate a bigger production cost ). It is possible to obtain animals with precocity and high KR, being well represented by the AB breed.(AU)

A seleção de animais com custos de produção mais baixos pode ser alcançada usando a eficiência alimentar e informações da curva de crescimento. A razão de Kleiber (KR) é uma alternativa para discriminar os animais que apresentam maior ganho de peso em relação ao peso final. Eficiência alimentar alternativa e curvas de crescimento para avestruzes das raças African Black (AB) e Red Neck (RN) e seus cruzamentos (CB) foram investigadas usando a equação de KR e Gompertz. Análises univariadas e multivariadas foram utilizadas. O maior peso adulto foi observado no RN e no CB. AB foi mais precoce do que os indivíduos RN e CB. Apenas animais AB atingiram 75% de seu peso adulto até um ano de idade. Aos 180 dias, AB tem maior KR. AB foi diferente dos demais, principalmente para KR aos 90 dias e 180 dias. Considerando a análise multivariada, os animais AB diferiram dos demais, independente do sexo, principalmente pelos seguintes parâmetros: KR aos 90 dias, KR aos 180 dias. Outros subgrupos separaram os animais por sexo. Em um mercado que prefere animais de menor estrutura corporal (cortes menores) e maior precocidade, seria adequado optar pela AB. Para animais com maior estrutura corporal (cortes maiores), os machos RN e CR são a melhor opção, porém, serão abatidos com maior idade e menor valor para KR (pode gerar um maior custo de produção). É possível obter animais com precocidade e alto KR, sendo bem representados pelo AB.(AU)

Assuntos

RESUMO

Estimation methods are routinely used to determine the body weight of a horse when a scale is not available. However, it is important to evaluate the accuracy and reliability of these predictions since nutritional management and drug dosage, among others, require knowledge of the animal’s weight. The objective of this study was to evaluate the accuracy and reliability of estimated weights of horses using two prediction models, and to discuss the effect of the predictions on animal management. Seventy-one adult male animals (40 mules and 31 horses) were weighed on a precision scale (control weight). Chest circumference and body length were measured and used to estimate body weight using the two models. Accuracy was evaluated by analysis of fit indices, comparison of squared prediction errors, delta Akaike’s information criterion, and decomposition of the mean squared error of prediction. For economic evaluation, three production scenarios were established: simple (worming + forage), traditional (worming + forage + concentrate mixture), and traditional with supplementation (worming + forage + concentrate mixture + supplementation). Economic values were collected through a pricing survey carried out in the Midwest region of Brazil and converted to US dollars. Percent differences in costs were evaluated using Fisher’s exact test. The most suitable model for the morphometric profile of the animals was that using a combination of chest circumference and body length. The differences in economic values between production scenarios were significant (P<0.05). Losses using the inadequate model are 10% higher compared to control; thus, in a facility with 20 equids that uses this model, the losses are ≈ US$ 10,000/year. When investment in a scale is not possible, it is fundamental to evaluate which model is more compatible with the body biotype of the herd since all types of management that depend on the body weight of the animals may result in significant economic losses.

Estimativas para determinar o peso corporal de um equino são rotineiramente usadas quando uma balança não está disponível. Todavia, é fundamental realizar um diagnóstico da acurácia e confiabilidade das predições destes estimadores, pois o manejo nutricional, dosificação de fármacos, entre outros, exigem o conhecimento do peso. Assim, objetivou-se avaliar a acurácia e confiabilidade de predições de peso estimado de equídeos utilizando dois modelos de cálculos e discutir o reflexo das predições no manejo dos animais. Foram pesados 71 equídeos machos (40 Muares e 31 Equinos) com idade adulta, em balança de precisão (peso controle). Medidas de perímetro torácico e comprimento corporal foram realizadas e utilizadas para estimar o peso corporal usando os modelos. A acurácia foi avaliada via análise do índice de adequação, comparação entre o quadrado do erro de predição, critério de informação Delta Akaike's e decomposição do erro quadrático médio da predição. Para avaliação econômica, criaram-se três cenários de produção: simples (vermifugação + volumoso), tradicional (vermifugação + volumoso + concentrado) e tradicional com suplementação (vermifugação + volumoso + concentrado + suplementação). Valores econômicos foram verificados em pesquisa de preço na região Centro Oeste do Brasil e convertidos em dólar. Avaliou-se as diferenças de percentagem dos custos utilizando teste de Fisher. O modelo mais adequado para o perfil morfométrico dos animais foi o que usa combinação entre perímetro torácico e comprimento corporal. Foram significativas (P<0,05) as diferenças para os valores econômicos nos cenários de produção. Prejuízos usando o modelo inadequado são 10% superiores em relação ao controle, assim em um estabelecimento com 20 equídeos que usa este modelo, os prejuízos são ≈ 10 mil dólares/ano. Na ausência da balança, é fundamental avaliar qual modelo de cálculo será mais compatível com biotipo corporal do rebanho, pois todo tipo de manejo que depende do peso corporal dos animais, pode gerar prejuízos econômicos significativos.

Assuntos

RESUMO

Dairy cattle production is distributed throughout the Brazilian regions. However, Brazilian producing regions are different in air temperature and humidity, diet, birth season, and other factors that may alter the reproductive performances of cows. The age of the cow at first calving (AFC) is a good indicator of sexual precocity since it shows the beginning of the female reproductive life and has a great influence on cow replacement costs. Researches on genotype-environment interaction (GEI) show the importance of using specific bulls for the different production systems in Brazil since most semen used in the country is imported. The objective of this work was to evaluate GEI for AFC in Holstein cows in Brazil, using reaction norms. The statistical models used were the standard animal model, which disregards the GEI, and hierarchical reaction norm models with homoscedastic (HRNMHO) and heteroscedastic (HRNMHE) residual variance, and one (HRNMHO1S and HRNMHE1S) and two (HRNMHO2S and HRNMHE2S) steps. HRNMHO1S presented better fit to the data, with lower heritability for environments with lower AFC, and higher heritability for environments with higher AFC. The GEI found was complex, with a reclassification of bulls, denoting the importance of considering GEI for evaluation and selection of bulls for different production levels. The reduction of AFC is possible when using breeding bulls adapted to the tropical and subtropical conditions of Brazil.

RESUMO

Brazil is the world's fourth largest milk producer; this activity extends throughout the national territory, with productions of approximate 34 billion liters of milk per year. The objective of this work was to evaluate the genotype-environment interaction (GEI) in purebred Holstein cows for milk (M), protein (P), and fat (F) yields. The statistical models used were the standard animal model (AM), which disregards the GEI, and hierarchical reaction norm models with homoscedastic (HRNMHO) and heteroscedastic (HRNMHE) residual variance, and one (HRNMHO1S and HRNMHE1S) and two (HRNMHO2S and HRNMHE2S) steps. HRNMHO1S presented a better fit of the data for all traits, with higher heritability for the best environments. Most bulls presented robust phenotypes; however, GEI was found with a reclassification of the bulls in the environmental gradient. Although few, and less used, bulls with plastic phenotypes were found for all traits, and the use of them can optimize genetic gains in specific environments.

Assuntos

RESUMO

Evaluating phenotypic diversity makes it possible to identify discrepancies in aptitudes among animals of different genetic bases, which is an indicator of adaptive or selective differences between populations. The objective of this work was to evaluate the morphofunctional diversity of 452 male and female adult equines (Arabian, Quarter Mile, Pantaneiro, and Criollo breeds, and undefined crossbreeds of horses and mules) raised in the Pantanal biome (Brazil). Linear measurements were performed to estimate conformation indexes. Initially, a discriminant analysis was performed, regardless of the animal's size, followed by factor analysis. The factors were characterized and used as new variables. The diversity among equines and their relationship with the factors were evaluated using multivariate analysis. The factors were classified according to their decreasing importance: balance, rusticity, and robustness for the measurement factors; and load, ability, conformation, and equilibrium for the index factors. The genetic groups of equines have well-defined morphofunctional characteristics. The main differences are based on the rusticity and ability typologies in relation to those based on performance. Equines introduced to the Pantanal biome presented a more robust and compact body with good conformation. As a result, these horses may have superior athletic performance during equestrian activities when compared to the Pantaneiro local breed. However, this biotype may represent less rusticity (less adaptive capacity). Therefore, the regional breed can be equal or better in equestrian activities than breeds introduced to the Pantanal biome. Thus, breeders may cross horses from local breeds as an alternative to those introduced. Undefined crossbred male equines presented a different profile from the Pantaneiro breed, which may indicate little use of crossbreeds in breeding.

Assuntos

RESUMO

The objectives of this work were to evaluate the genotype-environment interaction, and estimate geneticparameters, genetic trends, and performance dissimilarity-weight gain from birth to weaning (WGBW),adjusted weight to 205 days (W205), weight gain from weaning to 18 months of age (WG18), andadjusted weight to 550 days (W550)-in Nellore animals born between 1986 and 2012, and raised inpasture-based system in three different environmental gradients in Brazil. Data of 62,001 animals-11,729raised in the Alto Taquari/Bolsão region (ATBR), 21,143 raised in the Campo Grande/Dourados region(CGDR) and 29,129 raised in the western São Paulo/Paraná region (SPPR) in Brazil-were used. Thecontemporary groups were defined by sex, location, and birth year and season, with at least nineindividuals, two different environments, and breeding bulls with at least five progenies. The statisticalmodel contained the direct additive and residual genetic effects (random effects), and environmentaland contemporary group effects (fixed effects). Genetic parameters, genotype-environment interactionand genetic trends were estimates using animal model (uni- and/or bi- traits). The level of similaritybetween regions was evaluated using principal components. The animals raised in the CGDR hadsuperior performance regarding the traits evaluated. The direct heritability estimates ranged from 0.39to 0.44 (WGBW), 0.41 to 0.45 (W205), 0.42 to 0.55 (WG18) and 0.60 to 0.62 (W550). The maternalheritability of the traits ranged from 0.20 (WGBW), 0.12 to 0.18 (W205), 0.00 to 0.06 (WG18) and 0.02to 0.22 (W550). According to the Spearman correlation, the ranking of the breeding bulls in the regionsevaluated were different. The mean of Euclidean distance indicated low similarity between ATBR andCGDR (43.20), and ATBR and SPPR (29.24). CGDR and SPPR presented similarity of 17.84. Thebreed values increased over the years in the traits evaluated...(AU)

O objetivou-se avaliar as existências de interação genótipo x ambiente, estimar os parâmetros genéticos,tendências genéticas e dissimilaridade para o ganho de peso do nascimento a desmama (GPND),peso ajustado para os 205 dias (P205), ganho de peso da desmama aos 18 meses de idade (GP18)e peso ajustado aos 550 dias em animais da raça Nelore nascidos entre os anos de 1986 a 2012 ecriados a pasto em três gradientes ambientais distintos no Brasil. Utilizou-se informações de 62001animais: 11729 criados na região do Alto Taquari- Bolsão (RATB), 21143 animais na região de CampoGrande-Dourados (RCGD) e 29129 animais na região Oeste de São Paulo-Paraná (RSPR). Os gruposcontemporâneos foram compostos por sexo, fazenda, estação e ano de nascimento dos animais; tendono mínimo nove indivíduos; cada reprodutor tinha no mínimo cinco filhos e encontravam-se em pelomenos dois ambientes diferentes. O modelo estatístico continha os efeitos genéticos aditivo direto eresidual (efeitos aleatórios) e, como fixos, efeitos de fazenda e grupo de contemporâneos. Estimouseparâmetros genéticos, interação genótipo x ambiente e tendências genéticas (modelo animal unie bi característica). Avaliou-se o grau de similaridade entre as três regiões utilizando componentesprincipais. Animais criados na região de RCGD apresentam superioridade para as características de desempenho avaliadas. As estimativas de herdabilidades direta variaram entre: 0,39 a 0,44; 0,41 a 0,45;0,42 a 0,55 e 0,60 a 0,62 respectivamente para GPND, P205, GP18 e P550. Para herdabilidade materna para as mesmas características, variaram entre: 0,20; 0,12 a 0,18; 0,00 a 0,06 e 0,02 a 0,22. Com base na correlação de Spearman constatou-se alteração na classificação dos reprodutores por região. Adistância euclidiana média indicou menor similaridade da RATB com RCGD (43,20) e RSPR (29,24);para RCGD e RSPR o valor de similaridade foi 17,84. Ocorreu aumento nos valores genéticos ao longodos anos nas características...(AU)

Assuntos

RESUMO

The objectives of this work were to evaluate the genotype-environment interaction, and estimate geneticparameters, genetic trends, and performance dissimilarity-weight gain from birth to weaning (WGBW),adjusted weight to 205 days (W205), weight gain from weaning to 18 months of age (WG18), andadjusted weight to 550 days (W550)-in Nellore animals born between 1986 and 2012, and raised inpasture-based system in three different environmental gradients in Brazil. Data of 62,001 animals-11,729raised in the Alto Taquari/Bolsão region (ATBR), 21,143 raised in the Campo Grande/Dourados region(CGDR) and 29,129 raised in the western São Paulo/Paraná region (SPPR) in Brazil-were used. Thecontemporary groups were defined by sex, location, and birth year and season, with at least nineindividuals, two different environments, and breeding bulls with at least five progenies. The statisticalmodel contained the direct additive and residual genetic effects (random effects), and environmentaland contemporary group effects (fixed effects). Genetic parameters, genotype-environment interactionand genetic trends were estimates using animal model (uni- and/or bi- traits). The level of similaritybetween regions was evaluated using principal components. The animals raised in the CGDR hadsuperior performance regarding the traits evaluated. The direct heritability estimates ranged from 0.39to 0.44 (WGBW), 0.41 to 0.45 (W205), 0.42 to 0.55 (WG18) and 0.60 to 0.62 (W550). The maternalheritability of the traits ranged from 0.20 (WGBW), 0.12 to 0.18 (W205), 0.00 to 0.06 (WG18) and 0.02to 0.22 (W550). According to the Spearman correlation, the ranking of the breeding bulls in the regionsevaluated were different. The mean of Euclidean distance indicated low similarity between ATBR andCGDR (43.20), and ATBR and SPPR (29.24). CGDR and SPPR presented similarity of 17.84. Thebreed values increased over the years in the traits evaluated...

O objetivou-se avaliar as existências de interação genótipo x ambiente, estimar os parâmetros genéticos,tendências genéticas e dissimilaridade para o ganho de peso do nascimento a desmama (GPND),peso ajustado para os 205 dias (P205), ganho de peso da desmama aos 18 meses de idade (GP18)e peso ajustado aos 550 dias em animais da raça Nelore nascidos entre os anos de 1986 a 2012 ecriados a pasto em três gradientes ambientais distintos no Brasil. Utilizou-se informações de 62001animais: 11729 criados na região do Alto Taquari- Bolsão (RATB), 21143 animais na região de CampoGrande-Dourados (RCGD) e 29129 animais na região Oeste de São Paulo-Paraná (RSPR). Os gruposcontemporâneos foram compostos por sexo, fazenda, estação e ano de nascimento dos animais; tendono mínimo nove indivíduos; cada reprodutor tinha no mínimo cinco filhos e encontravam-se em pelomenos dois ambientes diferentes. O modelo estatístico continha os efeitos genéticos aditivo direto eresidual (efeitos aleatórios) e, como fixos, efeitos de fazenda e grupo de contemporâneos. Estimouseparâmetros genéticos, interação genótipo x ambiente e tendências genéticas (modelo animal unie bi característica). Avaliou-se o grau de similaridade entre as três regiões utilizando componentesprincipais. Animais criados na região de RCGD apresentam superioridade para as características de desempenho avaliadas. As estimativas de herdabilidades direta variaram entre: 0,39 a 0,44; 0,41 a 0,45;0,42 a 0,55 e 0,60 a 0,62 respectivamente para GPND, P205, GP18 e P550. Para herdabilidade materna para as mesmas características, variaram entre: 0,20; 0,12 a 0,18; 0,00 a 0,06 e 0,02 a 0,22. Com base na correlação de Spearman constatou-se alteração na classificação dos reprodutores por região. Adistância euclidiana média indicou menor similaridade da RATB com RCGD (43,20) e RSPR (29,24);para RCGD e RSPR o valor de similaridade foi 17,84. Ocorreu aumento nos valores genéticos ao longodos anos nas características...

Assuntos

RESUMO

Genetic breeding programs generally evaluate animals considering the same objectives, but the indices used in the selection criteria can vary. This can give rise to distinct bull rankings in each program. Thus, we aimed to create alternatives for the referral of bulls for mating through multivariate analyses. We used information from the summaries of two genetic evaluation programs (1 and 2) with Nellore bulls. Characteristics were separated into groups: weight, carcass and reproduction. Groups were formed using the mean Euclidean distance and the Tocher optimization method. The means of each trait among the animals allocated to the same group were used to compose the following subindexes: weight gain (siWG), carcass (siCG) and reproduction (siRG). Based on the mean of the group subindex classification, we calculated the average index of group classification (iAGc). When classifying the best groups by characteristics, we observed an increase (superiority of some bulls) in the estimated breeding values (EBVs) by comparison with the total number of bulls evaluated by the programs, selected animals and best 10 final indexes of the programs. There was a change in bull classification when using the iAGc in relation to the classification using the final indexes of the programs. The coefficient of simple coincidence showed that there was a change in bull classification between programs, both between deciles of the final indexes and groups of characteristics. The subindexes siWG, siCG and siRG are important for correcting specific problems inherds. The iAGc should be used instead of the final index of the programs, providing more options for the selection of bulls for mating.(AU)

Assuntos

RESUMO

Genetic breeding programs generally evaluate animals considering the same objectives, but the indices used in the selection criteria can vary. This can give rise to distinct bull rankings in each program. Thus, we aimed to create alternatives for the referral of bulls for mating through multivariate analyses. We used information from the summaries of two genetic evaluation programs (1 and 2) with Nellore bulls. Characteristics were separated into groups: weight, carcass and reproduction. Groups were formed using the mean Euclidean distance and the Tocher optimization method. The means of each trait among the animals allocated to the same group were used to compose the following subindexes: weight gain (siWG), carcass (siCG) and reproduction (siRG). Based on the mean of the group subindex classification, we calculated the average index of group classification (iAGc). When classifying the best groups by characteristics, we observed an increase (superiority of some bulls) in the estimated breeding values (EBVs) by comparison with the total number of bulls evaluated by the programs, selected animals and best 10 final indexes of the programs. There was a change in bull classification when using the iAGc in relation to the classification using the final indexes of the programs. The coefficient of simple coincidence showed that there was a change in bull classification between programs, both between deciles of the final indexes and groups of characteristics. The subindexes siWG, siCG and siRG are important for correcting specific problems inherds. The iAGc should be used instead of the final index of the programs, providing more options for the selection of bulls for mating.

Assuntos

RESUMO

Objetivou-se avaliar a estrutura populacional de 91.579 animais da raça Nelore criados no Semiárido Nordestino, nascidos entre 1965 e 2011. Analisaram-se o pedigree e a estimação dos parâmetros populacionais baseados na probabilidade de origem do gene. Nos primeiros anos, registraram-se nascimentos superiores de fêmeas, tendendo ao equilíbrio entre os sexos com o passar dos anos. Os números de efetivo de animais fundadores (fe) e ancestrais (fa) indicaram a utilização reduzida de animais na formação genética do rebanho. Dentre 24.676 ancestrais, 450 foram responsáveis por 50% da variabilidade genética da população. Dos 10 fundadores de maior importância, 8 se apresentam dentre os 10 ancestrais; o indivíduo com maior expressão apresentou coeficiente de relação médio (CR) de 1,31%, explicando 1,81% da variabilidade. 72% dos animais têm pais e mães identificados, observando-se perda de informação entre as gerações. 100% dos rebanhos utilizam touros externos e 61% deles vendem touros, não havendo classificação núcleo ou isolado. Endogamia variou de 0,14% na segunda geração a 0,73% na oitava, enquanto que o CR oscilou de 0,8% a 0,35% entre a primeira e a quarta geração, decrescendo a partir da quinta. Observou-se um intervalo médio de gerações de 8,3 anos. O rebanho possui número reduzido de animais na formação genética e pequena integralidade do pedigree, dificultando a estimativa de alguns parâmetros populacionais.(AU)

The objective of this study was to evaluate the population structure of 91,579 Nellore cattle reared in the Northeast semi-arid, born between 1965 and 2011. We analyzed the pedigree and the estimation of population parameters based on the probability of gene origin. In the early years, a higher number of female births occured, tending to gender balance over the years. The number of founder animals (fe) and ancestors (fa) indicated the reduced use of animals in the genetic formation of the herd. Among 2,4676 ancestors, 450 were responsible for 50% of the genetic variability of the population. Of the 10 most important founders, 8 were among the 10 ancestors. The individual with the highest expression presented a mean coefficient of relationship (CR) of 1.31%, explaining 1.81% of the variability. 72% of animals have identified fathers and mothers, revealing loss of information between generations. 100% of the herds use external bulls and 61% of them sell bulls, with no core classification or isolate. Inbreeding ranged from 0.14% in the second generation to 0.73% in the eighth, while the CR ranged from 0.8% to 0.35% between the first and fourth generations, decreasing from the fifth on. The average generation interval observed was of 8.3 years. The herd has a small number of animals in the genetic make-up, and small completeness of pedigree, making it difficult to estimate some population parameters.(AU)

Assuntos

RESUMO

Objetivou-se avaliar a estrutura populacional de 91.579 animais da raça Nelore criados no Semiárido Nordestino, nascidos entre 1965 e 2011. Analisaram-se o pedigree e a estimação dos parâmetros populacionais baseados na probabilidade de origem do gene. Nos primeiros anos, registraram-se nascimentos superiores de fêmeas, tendendo ao equilíbrio entre os sexos com o passar dos anos. Os números de efetivo de animais fundadores (fe) e ancestrais (fa) indicaram a utilização reduzida de animais na formação genética do rebanho. Dentre 24.676 ancestrais, 450 foram responsáveis por 50% da variabilidade genética da população. Dos 10 fundadores de maior importância, 8 se apresentam dentre os 10 ancestrais; o indivíduo com maior expressão apresentou coeficiente de relação médio (CR) de 1,31%, explicando 1,81% da variabilidade. 72% dos animais têm pais e mães identificados, observando-se perda de informação entre as gerações. 100% dos rebanhos utilizam touros externos e 61% deles vendem touros, não havendo classificação núcleo ou isolado. Endogamia variou de 0,14% na segunda geração a 0,73% na oitava, enquanto que o CR oscilou de 0,8% a 0,35% entre a primeira e a quarta geração, decrescendo a partir da quinta. Observou-se um intervalo médio de gerações de 8,3 anos. O rebanho possui número reduzido de animais na formação genética e pequena integralidade do pedigree, dificultando a estimativa de alguns parâmetros populacionais.

The objective of this study was to evaluate the population structure of 91,579 Nellore cattle reared in the Northeast semi-arid, born between 1965 and 2011. We analyzed the pedigree and the estimation of population parameters based on the probability of gene origin. In the early years, a higher number of female births occured, tending to gender balance over the years. The number of founder animals (fe) and ancestors (fa) indicated the reduced use of animals in the genetic formation of the herd. Among 2,4676 ancestors, 450 were responsible for 50% of the genetic variability of the population. Of the 10 most important founders, 8 were among the 10 ancestors. The individual with the highest expression presented a mean coefficient of relationship (CR) of 1.31%, explaining 1.81% of the variability. 72% of animals have identified fathers and mothers, revealing loss of information between generations. 100% of the herds use external bulls and 61% of them sell bulls, with no core classification or isolate. Inbreeding ranged from 0.14% in the second generation to 0.73% in the eighth, while the CR ranged from 0.8% to 0.35% between the first and fourth generations, decreasing from the fifth on. The average generation interval observed was of 8.3 years. The herd has a small number of animals in the genetic make-up, and small completeness of pedigree, making it difficult to estimate some population parameters.

Assuntos

RESUMO

Abstract Any equestrian activity requires horses with proper fitness, which can be identified through body conformation (BC), calculated by combined biometric measurements. The objective of this study was to evaluate the BC of 86 horses belonging to genetic groups (GG): Crioulo (CR), Brazilian Equestrian (BE), Arabian (ARB), Quarter Horse (QH), Thoroughbred (THO), and a crossbred group with small stature, named as Petiço (PE). We evaluated the relationship between shoulder and withers, estimated body weight, length, weight, weight relative, conformation, compactness and load 1 and 2, load on leg and dactyl-thoracic. The variation sources in the model were the effects of gender, GG, and the interaction GG*gender; the correlation between BC; principal components analysis, preparing a scatter plot with biplot to verify the distribution of GG in relation to the BC; cluster to check distance between GG. The variation sources affected BC (P 0.05). PE was considered elipometric, while the others were eumetric. THO was considered of medium shape, and the others as having small shape. Horses THO, QH, PE were qualified for activities with saddle up to light traction, and the rest of horses from saddle to heavy traction. Horses BE and ARB had greater capacity to support weight without overexertion on the back, working step and gallop. There were greater similarities between QM and CR, and lower among PE and the other GGs.

Resumo Qualquer atividade equestre exig e equino com aptidão adequada, podendo ser identificada através da conformação corporal (IC), calculada pela combinação de medidas biométricas. Objetivou-se avaliar IC de 86 equinos, pertencentes aos grupos genéticos (GG): Crioulo (CR), Brasileiro de Hipismo (BH), Árabe (ARB), Quarto de Milha (QM), Puro Sangue Inglês (PSI) e mestiços com pequena estatura corporal, rotulado Petiço (PE). Avaliaram-se relação cernelha garupa, peso corporal estimado, torácico, corporal, corporal relativo, conformação, compacidade e carga 1 e 2, carga na canela e dáctilo-torácico. Analisaram-se efeito de sexo (S), GG e interação S*GG; correlações entre IC; componentes principais, elaborando-se diagrama de dispersão com biplot, para se verificar a distribuição dos GG em relação aos IC; e cluster para verificar distância entre GG. Os efeitos foram responsáveis por variações (P 0,05) nos IC. Considerou-se o PE elipométrico e os demais, eumétricos. Considerou-se o PSI mediolíneo e os demais, brevilíneos. Equinos PSI, QM e PE apresentaram-se aptos para executar atividades com sela até tração leve e o restante, até tração pesada. Equinos BH e ARB apresentaram maior capacidade de suportar peso sem esforço exagerado sobre o dorso, trabalhando a passo e ao galope. Observaram-se maior similaridade entre QM e CR e menor entre PE com os GG.

RESUMO

Any equestrian activity requires horses with proper fitness, which can be identified through body conformation (BC), calculated by combined biometric measurements. The objective of this study was to evaluate the BC of 86 horses belonging to genetic groups (GG): Crioulo (CR), Brazilian Equestrian (BE), Arabian (ARB), Quarter Horse (QH), Thoroughbred (THO), and a crossbred group with small stature, named as Petiço (PE). We evaluated the relationship between shoulder and withers, estimated body weight, length, weight, weight relative, conformation, compactness and load 1 and 2, load on leg and dactyl-thoracic. The variation sources in the model were the effects of gender, GG, and the interaction GG*gender; the correlation between BC; principal components analysis, preparing a scatter plot with biplot to verify the distribution of GG in relation to the BC; cluster to check distance between GG. The variation sources affected BC (P 0.05). PE was considered elipometric, while the others were eumetric. THO was considered of medium shape, and the others as having small shape. Horses THO, QH, PE were qualified for activities with saddle up to light traction, and the rest of horses from saddle to heavy traction. Horses BE and ARB had greater capacity to support weight without overexertion on the back, working step and gallop. There were greater similarities between QM and CR, and lower among PE and the other GGs.

Qualquer atividade equestre exig e equino com aptidão adequada, podendo ser identificada através da conformação corporal (IC), calculada pela combinação de medidas biométricas. Objetivou-se avaliar IC de 86 equinos, pertencentes aos grupos genéticos (GG): Crioulo (CR), Brasileiro de Hipismo (BH), Árabe (ARB), Quarto de Milha (QM), Puro Sangue Inglês (PSI) e mestiços com pequena estatura corporal, rotulado Petiço (PE). Avaliaram-se relação cernelha garupa, peso corporal estimado, torácico, corporal, corporal relativo, conformação, compacidade e carga 1 e 2, carga na canela e dáctilo-torácico. Analisaram-se efeito de sexo (S), GG e interação S*GG; correlações entre IC; componentes principais, elaborando-se diagrama de dispersão com biplot, para se verificar a distribuição dos GG em relação aos IC; e cluster para verificar distância entre GG. Os efeitos foram responsáveis por variações (P 0,05) nos IC. Considerou-se o PE elipométrico e os demais, eumétricos. Considerou-se o PSI mediolíneo e os demais, brevilíneos. Equinos PSI, QM e PE apresentaram-se aptos para executar atividades com sela até tração leve e o restante, até tração pesada. Equinos BH e ARB apresentaram maior capacidade de suportar peso sem esforço exagerado sobre o dorso, trabalhando a passo e ao galope. Observaram-se maior similaridade entre QM e CR e menor entre PE com os GG.

Assuntos

RESUMO

Any equestrian activity requires horses with proper fitness, which can be identified through body conformation (BC), calculated by combined biometric measurements. The objective of this study was to evaluate the BC of 86 horses belonging to genetic groups (GG): Crioulo (CR), Brazilian Equestrian (BE), Arabian (ARB), Quarter Horse (QH), Thoroughbred (THO), and a crossbred group with small stature, named as Petiço (PE). We evaluated the relationship between shoulder and withers, estimated body weight, length, weight, weight relative, conformation, compactness and load 1 and 2, load on leg and dactyl-thoracic. The variation sources in the model were the effects of gender, GG, and the interaction GG*gender; the correlation between BC; principal components analysis, preparing a scatter plot with biplot to verify the distribution of GG in relation to the BC; cluster to check distance between GG. The variation sources affected BC (P 0.05). PE was considered elipometric, while the others were eumetric. THO was considered of medium shape, and the others as having small shape. Horses THO, QH, PE were qualified for activities with saddle up to light traction, and the rest of horses from saddle to heavy traction. Horses BE and ARB had greater capacity to support weight without overexertion on the back, working step and gallop. There were greater similarities between QM and CR, and lower among PE and the other GGs.(AU)

Qualquer atividade equestre exig e equino com aptidão adequada, podendo ser identificada através da conformação corporal (IC), calculada pela combinação de medidas biométricas. Objetivou-se avaliar IC de 86 equinos, pertencentes aos grupos genéticos (GG): Crioulo (CR), Brasileiro de Hipismo (BH), Árabe (ARB), Quarto de Milha (QM), Puro Sangue Inglês (PSI) e mestiços com pequena estatura corporal, rotulado Petiço (PE). Avaliaram-se relação cernelha garupa, peso corporal estimado, torácico, corporal, corporal relativo, conformação, compacidade e carga 1 e 2, carga na canela e dáctilo-torácico. Analisaram-se efeito de sexo (S), GG e interação S*GG; correlações entre IC; componentes principais, elaborando-se diagrama de dispersão com biplot, para se verificar a distribuição dos GG em relação aos IC; e cluster para verificar distância entre GG. Os efeitos foram responsáveis por variações (P 0,05) nos IC. Considerou-se o PE elipométrico e os demais, eumétricos. Considerou-se o PSI mediolíneo e os demais, brevilíneos. Equinos PSI, QM e PE apresentaram-se aptos para executar atividades com sela até tração leve e o restante, até tração pesada. Equinos BH e ARB apresentaram maior capacidade de suportar peso sem esforço exagerado sobre o dorso, trabalhando a passo e ao galope. Observaram-se maior similaridade entre QM e CR e menor entre PE com os GG.(AU)

Assuntos

RESUMO

The primary aim of this study was to characterize the phenotypes of equines raised in the Pantanal region of Mato Grosso do Sul, one of the central-western states of Brazil. Eighteen linear measurements were collected from 498 adult horses belonging to several different breeds, including Pantaneira (n = 52), Arabic (n = 28), Crioulo (n = 31), Mangalarga (n = 8), Quarter Horse (n = 97), Petiço (n = 9), Crossbred Horses (i.e., undetermined breeding; n = 170), and Mules (n = 74). These measurements were compared to similar measurements taken of English Thoroughbreds (n = 14) and Brazilian Equestrians (n = 15) in the city of Campo Grande, the capital of Mato Grasso do Sul. We used analysis of variance to test the influence of several factors, including genetic group, category (horse or mule), sex, and their interactive effects, on phenotypic characteristics. Correlation estimates verified the Euclidean distance between genetic groups categorized via cluster analysis. The effects were significant (P<0.05) for many of the phenotypic characteristics. Horses showed higher values for most of the measurements compared to mules, except for the length of the head, lumbar back length, and cannon bone circumference, as well as greater correlation between weight and heart girth (r = 0.98). Cluster analysis determined that the animals were categorized into nine groups, with 10 distinct populations. Correspondence analysis showed that the Crioulo, Crossbred Horses, Mules, Pantaneiro, and Mangalarga breeds were less distinct phenotypically. The Petiço breed was not grouped, whereas Quarter Horses, English Thoroughbreds, and Brazilian Equestrians were more phenotypically distinct from the other breeds.(AU)

Objetivou-se caracterizar fenotipicamente os equídeos criados no Pantanal do Mato Grosso do Sul. Mensuraram-se 18 medidas lineares em 498 equídeos adultos pertencentes às raças Pantaneira (n = 52), Árabe (n = 28), Crioulo (n = 31), Mangalarga (n = 8), Quarto de Milha (n = 97), Petiço (n = 9), equinos mestiços (n = 170) e Muares (n = 74).Para realizar distâncias fenotípicas incluiu-se informações das raças Puro Sangue Inglês (n=14) e Brasileiro de Hipismo (n = 15), mensurados em Campo Grande- MS. Realizou-se análise de variância para verificar influência dos efeitos de grupo genético, categoria (equino ou muar), sexo, e suas interações; analisaram-se correlações fenotípicas e para verificação da distância euclidiana entre grupos genéticos realizou-se analise de cluster. Os efeitos de variância foram significativos (P<0,05) em muitas das características fenotípicas. Os equinos em relação aos muares apresentaram valores superiores para maior parte das medidas, exceto para o comprimento de cabeça, comprimento dorso lombar e perímetro de canela. Obtiveram maiores correlações fenotípicas entre peso e perímetro torácico (r = 0,98). A análise de agrupamento possibilitou verificar que os equídeos foram categorizados em 9 grupos, com 10 populações distintas. A análise de correspondência apresentou diferenças menos notáveis em seus padrões fenotípicos entre as raças Crioula, equinos mestiços, Muares, Pantaneiros e Mangalarga. O grupamento Petiço foi o único que tendeu a não se agrupar. As raças Quarto de Milha, Puro Sangue Inglês, Brasileiro de Hipismo apresentam padrões fenotípicos com maior distância em relação aos demais.(AU)

Assuntos

RESUMO

We analyzed the pregnancy rate (PR) and birth rate (BR) of Nellore cows raised extensively in the Cerrado/Pantanal during 4 mating seasons (20092012), assessing the relationship with the temperature and humidity index (THI) and the effect of the year and breeding season. We used information from 2,116 cows, which were categorized as either multiparous (n = 1430), primiparous (n = 338), or nulliparous (n = 348). In the months of the breeding season (DecemberFebruary), temperature and relative humidity data were collected to calculate the temperature and humidity index (THI). An ANOVA was performed with a model that included sources of variation from the fixed effects of category of cow and year on PR and BR; and a linear regression analysis and correlation between THI and PR and BR. We observed a significant effect (p 0.05) on PR. We classified the average across breeding seasons as a moderate THI. The THI of the breeding seasons showed high and significant (p 0.05) effects only on the nulliparous BR, and low values in other categories. It is concluded that the seasonal THI was not related to the performance of cows, except BR in nulliparous cows(AU)

Analisou-se taxa de prenhez (TP) e de natalidade (TN) de matrizes Nelores criadas extensivamente no Cerrado/Pantanal, acasaladas durante 4 estações de monta natural (2009 a 2012), avaliando relação com índice de temperatura e umidade (ITU) e efeito do ano da estação de monta. Utilizaram-se 2.116 informações de matrizes, pertencentes às categorias de multíparas (n = 1430), primíparas (n = 338) e nulíparas (n = 348). Nos meses de estação de monta (dezembro a fevereiro) coletaram-se informações da temperatura e umidade relativa do ar, para o cálculo de índice de temperatura e umidade (ITU). Realizaram-se análise de variância com um modelo contendo como fontes de variação os efeitos fixos de categoria e ano de estação de monta sob a TP e TN; e análise da regressão linear e correlação entre o ITU e a TP e TN. Observaram-se efeito significativo (p 0,05) de categoria sob a TP. Classificou-se o ITU médio entre as estações de monta como moderado. O ITU das estações de monta apresentou relação alta e significativa (p 0,05) apenas na TN das nulíparas, e baixas tendências de relação com as demais. Conclui-se que o ano da estação de monta e o ITU não apresentaram relação com desempenho das matrizes, exceto as nulíparas considerando ITU e TN(AU)

Assuntos

RESUMO

Purebred and crossbred calves (n = 3,871) were selected that were born in the sub-region of the Pantanal of Aquidauana (Brazil), derived from Nellore, Brangus, Wagyu, and ½ Brangus + ½ Nellore cows, which were artificially inseminated by bulls of the Aberdeen Angus, Red Angus, Brangus, Nellore, and Wagyubreeds. Parameters such as weaning weight, daily gain from birth to weaning, and the number of days to gain 160 kg, were assessed inthese calves and phenotypic correlations between the traits were evaluated. Data were analyzed using two statistical models. The first model included sire breed effects, the genetic group of the cow, sex, year of birth (AN), birth season (EN), and the interaction AN * EN. The second model included the genetic group of the calf, sex, AN, EN, and the interaction AN * EN. The genetic group of the cow and calf and the interaction AN * EN did not significantly affect body weight (p 0.05). The average weaning weights of progeny were as follows: Aberdeen Angus bulls, 177.70 ± 3.28 kg; Red Angus, 180.31 ± 3.46 kg; Brangus, 181.48 ± 3.15 kg; Nellore, 175.43 ± 3.60 kg; and Wagyu, 173.16 ± 2.96 kg.(AU)

Utilizaram-se informações de 3.871 bezerros puros e cruzados, provindos de fêmeas das raças: Nelore, Brangus, Wagyu e ½ Brangus vs. ½ Nelore, as quais receberam o sêmen proveniente de touros das raças Aberdeen Angus, Red Angus, Brangus, Nelore e Wagyu para avaliar efeitos sobre o peso a desmama, ganho diário de peso do nascimento a desmama e o número de dias para se obter 160 kg de bezerros nascidos na sub-região do Pantanal de Aquidauana (Brasil), avaliando correlações fenotípicas entre as características. Analisaram-se os dados, utilizaram-se dois modelos estatísticos. O primeiro incluiu efeitos de raça do touro, grupo genético da vaca, sexo, ano de nascimento (AN), estação de nascimento (EN) e interação AN*EN. O segundo incluiu grupo genético do bezerro, sexo, AN, EN e interação AN*EN. Grupo genético da vaca e interação AN*EN do bezerro não influenciou (p 0.05) no peso ao desmame. Observou-se peso médio ao desmame para filhos de touros Aberdeen Angus de 177,7 ± 3,3 kg, Red Angus de 180,3 ± 3,5 kg, Brangus de 181,48 ± 3,2 kg, Nelore de 175,4 ± 3,6 kg e Wagyu de 173,1 ± 3,0 kg.(AU)

Assuntos