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

ASSOCIAÇÃO ENTRE EFICIÊNCIA ALIMENTAR E PRECOCIDADE SEXUAL EM FÊMEAS DA RAÇA NELORE.

Abstract: The aimed of this study was to evaluate the relationship between feed efficiency and sexual precocity traits in Nellore heifers. The reproductive and feed efficiency data of 151 Nellore females were used, from which were collected: RFI, dry matter intake (DMI), feed conversion (FC), feed efficiency (FE), uterine tract score (UTS) and early pregnancy (GEST), as a binary trait. Correlation analysis and analysis of variance between the linear traits (RFI, DMI, FC, FE) was performed. For the threshold traits (UTS and GEST), the correlation coefficient was obtained considering coefficient of determination? square root of an adjusted logistic regression model. To verify the association between these traits and the RFI classifications, a Chi-square test was performed. The correlation between DMI and feed efficiency traits, demonstrate that RFI, FC and FE can be used as an indicator of the animals that presented lower consumption. Among feed efficiency and sexual precocity traits, low and no significant correlations were observed. For UTS and GEST, a low magnitude correlation was observed. Among RFI classes, significant differences (P <0.05) were observed for DMI and FC. For sexual precocity traits and RFI classes, https://proceedings.science/p/105322no significant difference was observed. Selection for feed efficiency does not influence the performance for sexual precocity in Nellore female

Índices de seleção fenotípica para zebuínos de corte participantes de prova de desempenho a pasto.

Resumo ? Objetivou-se avaliar a sensibilidade e as relações entre características utilizadas nos índices de seleção fenotípica para a proposição de um novo índice de seleção de classificação de animais zebuínos de corte participantes dos testes de desempenho a pasto. Foram utilizadas informações de testes realizados pela Embrapa Cerrados entre 2016 e 2022. As características de ganho médio diário (GMD), peso calculado para 550 dias (PC550), avaliação visual (AV), perímetro escrotal (PE), volume testicular (VT), acabamento de carcaça (ACAB) e área de olho de lombo (AOL) foram avaliadas em 772 touros jovens. Foram realizadas análises de sensibilidade para cinco índices de seleção de testes de desempenho, além de análises de correlações de ranking, equações estruturais e relações causais. A sensibilidade dos índices para as características que os compõem e a relação entre elas foram influenciadas pela amplitude de cada uma característica. A redução da ponderação de ACAB e a inclusão de VT resultaram em um índice mais harmônico. A associação de PE e VT aumentou a influência da reprodução na classificação dos animais. O índice composto por PC550, GMD, AV, PE, AOL, ACAB e VT se mostrou mais harmônico, menos sensível à variação das características e mais adequado para evitar a escolha de animais extremos

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

Tendência genética para características de crescimento e reprodução em bovinos avaliados em teste de desempenho.

Objetivou-se avaliar as tendências genéticas para as características de crescimento e reprodução de bovinos Nelore avaliados em Teste de Desempenho de Touros Jovens

Variabilidade genética nos testes de desempenho de touros jovens conduzidos na Embrapa Arroz e Feijão.

Objetivou-se com este trabalho avaliar a relação entre valores genéticos aditivos dos touros participantes das provas e os valores genéticos aditivos médios de suas respectivas progênies

Utilização de marcadores microssatélites no melhoramento populacional do arroz.

Introdução; Estudo de caso - análise molecular da cultivar Tio Taka por marcadores microssatélites; Análise dos genitores da população CNA-IRAT; Variabilidade genética do germoplasma de arroz; Escolha de genitores para a composição de novas populações de seleção recorrente; Considerações finais.bitstream/CNPAF/23246/1/doc_169.pd

Extratos vegetais como moduladores da fermentação ruminal.

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Evolução genética para características de carcaça em bovinos Nelore sob seleção para maciez da carne.

Objetivou-se com este trabalho avaliar as tendências genéticas para características de carcaça e conformação frigorifica em bovinos Nelore submetidos à seleção genética para maciez da carne (WBSF)