Avaliação da severidade e reação de resistência a doenças em cinco espécies de trevos na safra 2021.

A produção de forragem no Sul do país está intimamente relacionada com à produtividade de bovinos de corte e de leite no período de inverno, quando as pastagens cultivadas ou naturais são reduzidas, como consequência da enorme carência de alimentação para o gado durante essa estação do ano (Reis, 2007; Montardo, 2002).ODS 2

Correlation between residual feed intake and daily water intake in confined nellore bulls.

Identifying efficient animals is an alternative to reduce food costs and natural resources used in farming. The objective of this study was to identify the correlation between Residual Feed intake (RFI) and Daily Water Consumption (DWC) in Nellore cattle. The work was realized at Núcleo Regional of Embrapa Cerrados, in June, 2017. Were used 44 bulls, aged between 18 and 21 months and initial weight of 455 kg. The diet was given twice daily, with corn silage: concentrate of 60:40. Feed intake was obtained in the feeders of Intergado System. Daily water consumption was measured by water drinked in electronic drinking fountains coupled to the automatic scales (Intergado System TM) plus water from feed. The RFI was calculated by means of the difference between the observed dry matter intake (DMIobs) and the expected dry matter intake (DMIexp) based on live weight (LW) and average daily gain (ADG). The descriptive statistics, comparison of means by Tukey test at 5% probability and Pearson correlations for the study traits were performed using software R (version 3.3.2). Groups of high, low and mean RFI were formed with one Standar Desviation of the mean RFI. The water consumption averaged 38.9 L / day, with a standard deviation of 6.1 L / d, and a minimum value of 30.0 and a maximum of 62.2 L / day. The RFI had zero and standard deviation of 1.01 kg / d, with a minimum value of -2.38 and a maximum of 2.7. The correlation between RFI and DWC was .24, being considered of low magnitude. It was not observed differences between RFI groups, with means of 37.0, 38.8 and 42.3 L / d, respectively, to Low, Medium and High RFI Groups. We concluded that water intake was not correlated with RFI in Nellore bulls confined in the early dry season of Brazil

Genetic association between growth and maternal ability traits in Nelore cattle.

Although body weight traits have been widely used in animal breeding programs due to their importance to beef cattle systems, the use of maternal ability traits, which highly affect the profitability in livestock, is still incipient. As the knowledge of genetic parameters of economic important traits may aid genetic gains, this study was carried out to estimate genetic parameters for weight at 120 and 210 days of age (W120 and W210), pre-weaning average daily gain (PreDG), real fertility (RF), accumulated productivity (AP) and weaning rate (WR). The data set was obtained from Vera Cruz Ranch, a cattle ranch that participates in the Brazilian National Association of Breeders and Researchers (ANCP). Heritabilities and correlations were estimated using univariate and bivariate linear mixed model. The model included contemporary groups (year and season of birth, sex and management group), cow age at calving (in classes and as linear and quadratic covariate) as fixed effects, and genetic and residual components as random effects. Estimates of heritability for between growth and maternal ability traits ranged from 0.22 to 0.32, indicating that they could be improved by direct selection. Estimates of genetic correlation between W120-W210, W120-PreDG, W120-RF, W120-AP, W120-WR were 0.90, 0.54, 0.16, 0.45 and 0.24, respectively. Estimates of genetic correlation between W210-PreDG, W210-RF, W210-AP, W210-WR were 0.63, 0.27, 0.53 and 0.21, respectively. Estimates of genetic correlation between PreDG-RF, PreDG-AP, PreDG-WR were 0.23, 0.16 and 0.28, respectively. Positive genetic correlations were observed between RF, CAP and RD (0.28 to 0.78). Therefore, genetic selection having one of these characteristics as the criterion of selection will lead to an indirect response in the same direction in the others. These results indicate that the use of animals with high breeding values for weights and pre-weaning gain may lead to increase maternal ability traits due to correlated responses. Such responses tend to be bigger when using weight compared to the pre-weaning gain

Milheto como silagem comparado a gramíneas tradicionais: aspectos quantitativos, qualitativos e econômicos.

PT-BR: Foram avaliados a composição morfológica, os parâmetros agronômicos, a produção de massa seca das plantas forrageiras utilizadas para o processo de ensilagem, bem como a caracterização do processo fermentativo, em diferentes tempos de abertura dos mini-silos (3, 7, 15, 30, 60, 120 dias) após a ensilagem. Procedeu-se também às determinações das perdas de efluentes e gases, além da composição bromatológica e fracionamento de proteína das silagens. Também foi estimado o custo de produção e a produção de leite em função da matéria seca das silagens produzidas a partir de diferentes gramíneas. As espécies forrageiras avaliadas foram: milheto ADR-7010, sorgo BRS 610, milho AG 5055 com espiga, milho AG 5055 sem espiga e cana-de-açúcar IAC 86-2480. Foram observadas diferenças significativas tanto para produção, quanto composição bromatológica e custos de produção. O milheto não se mostrou competitivo com as demais forrageiras; entretanto, constitui opção como cultura de inverno em decorrência de sua baixa exigência hídrica quando comparado às demais culturas. | EN: In this assay, we evaluated morphological composition, agronomic parameters, dry matter yield, and the silage fermentative process from pearl millet, sorghum, and corn plant with or without ears within different silos opening times (3, 7, 15, 30, 60, and 120 days). Effluent and gas release from silages were also evaluated besides its chemical composition and protein fractioning. Production costs of all silages were estimated. We also estimate milk production according to different silages dry matter production. Evaluated cultivars were, ADR-7010 (pearl millet), BRS-610 (sorghum), AG-5055 (corn), and IAC-86-2480 (sugarcane). Significant differences were observed for both production as well as chemical composition and production costs. Pearl millet did not prove to be competitive when compared with other forages. However, as winter crop, pearl millet could be profitable due to the low water exigencies when compared to the other crops

Análises de dados longitudinais em bovinos nelore mocho por meio de modelos não lineares.

201

Associação genética entre escores visuais e características reprodutivas em bovinos Nelore.

A utilização de escores visuais como critério de seleção tem como vantagem a avaliação em animais jovens quanto ao potencial desempenho produtivo e reprodutivo, antecipando a tomada de decisão em comparação a medidas tomadas de forma objetiva, como perímetro escrotal aos 450 dias (PE450) e stainability (STAY). Objetivou-se estimar os parâmetros genéticos de características morfológicas e reprodutivas em bovinos Nelore, a fim de avaliar a associação entre essas características

Associação genética entre eficiência alimentar e características de crescimento, reprodução e carcaça em bovinos da Raça Guzerá.

Resumo ? A raça Guzerá apresenta grande contribuição para pecuária brasi- leira devido a sua rusticidade e por apresentar índices produtivos favoráveis quanto ao crescimento, fertilidade e eficiência alimentar. O objetivo desse estudo foi estimar os parâmetros genéticos, a correlação genética para a efi- ciência alimentar e as características produtivas de bovinos da raça Guzerá. As herdabilidades para características de crescimento e reprodução, P120, P210, P365, P450, PE365 e PE450, respectivamente, apresentaram coefi- cientes que variaram entre baixos a moderados, 0,17 a 0,39, assim como para características de carcaça, 0,09 a 0,31, ao passo que as característi- cas de eficiência alimentar apresentaram baixa herdabilidade, 0,14 a 0,23. O CAR apresentou baixas correlações genéticas com características de cresci- mento variando de -0,07 a 0,22, de 0,03 a 0,05 para características de repro- dução, e de -0,35 a 0,16 para carcaça, com exceção do CMS, que variou de 0,42 a 0,46. As estimativas de herdabilidade verificadas neste estudo indicam que ganhos genéticos significativos podem ser obtidos através da seleção de características de eficiência alimentar, crescimento, reprodução e carcaça na raça Guzerá. As correlações genéticas encontradas entre o CAR e as demais características mostraram que estas podem ser inseridas simultaneamente em programas de seleção, sem respostas correlacionadas desfavoráveis en- tre elas

Avaliação de crescimento, reprodução e carcaça de raças zebuínas em teste de desempenho.

Objetivou-se avaliar características de crescimento, reprodução e carcaça em touros jovens das raças Nelore e Tabapuã, a fim de verificar se há relação de raças com o desempenho obtido em Teste de Desempenho de Touros Jovens

Characterization and genetic diversity in Paspalum notatum Flügge accessions: Morphological and geographical distance

The objective of this work was to describe morphology and grouping of Paspalum notatum accessions, based on multicategorical data which discards the redundant variables for quantification of genetic diversity. We also tested the hypothesis that geographical distance was correlated with morphological divergence. In our study, multivariate analyzes successfully demonstrated the geographic and morphological variability of the P. notatum accessions characterized. Many of these evaluated accessions can be included in future genetic improvement programs. Based on two methodologies for discarding variables, it was possible to identify the potentially important morphological characteristics from genetic diversity studies and characterize new accessions aimed at improving forage and seed production. The methodologies used to discard variables are biometric tools that can be used successfully in future plant breeding programs, especially when a large number of traits and accessions are being evaluated. Although significant, geographic distance had a low association with morphological traits. This indicated the need to use other characteristics, such as forage and seed yield, in addition to molecular analysis. Our analyzes showed genetic variability in P. notatum for all the characteristics studied

Genetic parameters, prediction of gains and intraspecific hybrid selection of Paspalum notatum Flügge for forage using REML/BLUP

Genetic improvement of native forage species is a sustainable alternative for maximizing livestock production. Paspalum notatum Flügge is the most important forage grass in the native grasslands of southern Brazil, with substantial potential available for further genetic improvement. The objective of this study was to quantify a range of genetic parameters and predict yield gains in a population of P. notatum intraspecific hybrids. Results indicated intraspecific hybrids of P. notatum had high magnitudes of heritability in the broad and average sense of genotype, plus high selective accuracy and genetic variation for all forage characteristics evaluated. This indicated REML/BLUP can contribute useful information for plant selection in future plant breeding programs. The genetic material studied showed high genetic variability for forage production. Analysis indicated hybrids 336, 332, 437, 132 and male parent '30N' should be included in new crosses to increase the dry matter production of P. notatum. Parents need to be selected from different groups in order to maximize genetic variability and heterosis. In addition, these parents must be included in diallel crosses. The results obtained in this study provide important information for the future breeding of improved P. notatum cultivars for commercialization