1,203 research outputs found
Um panorama da colaboração científica na pesquisa agroinformática brasileira.
O presente artigo visa apresentar uma abordagem para identificar e analisar a rede de colaboração entre instituições no escopo da pesquisa em informática agropecuária no país, a partir da análise dos 139 artigos publicados nos anais do X Congresso Brasileiro de Agroinformática, ocorrido em 2015.SBIAgro
Recuperação de áreas degradadas através da introdução de gramíneas forrageiras e de leguminosas arbóreas no Estado do Rio de Janeiro.
O município de Paty do Alferes está situado na região subtropical montanhosa da Mata Atlântica do Estado de Rio de Janeiro. A erosão e seus associados efeitos representam sérios problemas ao ambiente. A principal razão para a erosão nesta região, é a utilização de solos inapropriados para agricultura anual associado a sistemas agrícolas não adequados as condições pedo-ambientais. O principal objetivo foi implantar módulos de pesquisa na fazenda, para recuperar áreas agrícolas/hortícolas degradadas, em topografia forte ondulada com 40% de declive, apresentando vários sulcos ao longo do declive. Os resultados mostraram que os módulos sob Brachiaria brizantha cv marandu e Digitaria swaziladensis (grama Swazi) foram os mais eficientes na produção de massa seca, mas a grama Swazi apresentou melhores efeitos nas propriedades dos solos. Os módulos com leguminosas arbóreas mostraram que a Erytrina velutina (Eritrina), Acácia mangium (Acácia) e Mimosa caesalpinaefolia (Sabiá) foram os mais eficientes para o conjunto de parâmetros estudados.bitstream/CNPS-2010/11240/1/bp182000leguminosas.pd
Relação entre altura e massa de forragem de uma pastagem anual de inverno em sistema silvipastoril.
O objetivo do presente estudo foi avaliar a influência da presença de árvores na relação entre a altura e massa de forragem de uma pastagem de aveiapreta com azevém. O estudo foi realizado entre agosto e setembro/2012 na Fazenda Modelo do IAPAR, Ponta Grossa, PR. A área experimental apresentava 12 piquetes (0,95 ha cada), sendo a metade deles arborizado com eucalipto, aroeira e grevílea. O delineamento foi em blocos ao acaso com 4 tratamentos: presença vs. ausência de árvores e dois níveis de nitrogênio (N) na pastagem (90 e 180 kg N ha-1), com 3 repetições. O método de pastejo foi o contínuo com carga animal variável, visando manter a altura da pastagem em torno de 20 cm. Foram utilizadas 4 novilhas Purunã (testers) por piquete. Diferenças significativas foram observadas (P<0,001) nos interceptos e nos coeficientes angulares, quando comparando as regressões entre altura e massa de forragem dos dois sistemas (i.e. com e sem árvores) e em cada nível de N. Para uma mesma altura média da pastagem, menores valores de massa de forragem foram observados no sistema arborizado
Polimorfismos no éxon 3 do gene JY-1 e suas associações com probabilidade de prenhez precoce e características de crescimento em novilhas da raça Nelore.
A probabilidade de prenhez precoce é uma característica importante devido ao alto valor econômico associado. Marcadores moleculares promovem diminuição do intervalo de gerações e aumento de ganho genético. A proteína JY-1 é uma proteína específica dos oócitos e atua nas células da granulosa e no desenvolvimento embrionário inicial. Marcadores moleculares foram usados para estudar o gene JY-1 e foram encontrados quatro polimorfismos do tipo SNP no éxon 3. As posições dos SNPs no referido éxon e as substituições são: 163 (T/C), 281(T/C), 321(T/C) e 679(T/C). O SNP 163 está em região codificante e causa substituição de uma prolina por uma leucina. Os demais SNPs estão em região 3?UTR. Os SNPs foram genotipados em 297 novilhas da raça Nelore. Os SNPs 163, 321 e 679 estavam em desequilíbrio de ligação entre si e em equilíbrio com o 281. Os genótipos foram correlacionados com probabilidade de prenhez precoce e características de crescimento, mas não se apresentaram significativos
Methane Emissions from Ruminants on Integrated Crop-Livestock Systems
Ruminant livestock produce ~80 million tonnes of methane (CH4) annually, accounting for ~33% of global anthropogenic emissions of CH4 (Beauchemin et al. 2008). CH4 is a powerful greenhouse gas, with global warming potential of 25 (Eckard et al. 2010), and represents a significant loss of dietary energy (2 to 12% of gross energy of feeds; Patra 2012) in the ruminant production system. Despite greenhouse gas (GHG) emissions have become an increasingly important topic worldwide, there is still a high variability around the estimated values of these emissions, mainly about emissions attributable to livestock (range from 8 to 51%; Herrero et al. 2011). This variability creates confusion among researchers, policy makers and the public, particularly in tropical/sub-tropical regions due substantial uncertainties. Therefore, using rigorous and internationally accepted protocols, a Brazilian national project was established in order to contribute for the estimates of GHG emissions attributable to livestock in Brazilian ruminant production systems. Moreover, enteric CH4 emissions are a major challenge for research, in order to develop technologies and strategies for sustainable ruminant production systems in the future (Eckard et al. 2010).
In recent years, integrated crop-livestock systems (ICLS) have gained interest due to, for example, the abatement of methane from livestock production: directly through a reduction in CH4 per unit of animal products resulting from the increase on feed quality and animal welfare (i.e. improved environmental temperature for ICLS with trees), and indirectly through reduction of area submitted to land use changes (i.e. leading to a loss of soil C stocks). This paper deals with the preliminary results from CH4 emissions by beef heifers grazing in two ICLS (i.e. production system that integrates corn or soybeans crops, during the warm season, and cattle grazing on a cool season pasture, on the same area and in the same cropping year, with or without trees), how these findings contributes to determine the soil C balance and mitigation measures
Interactive Tree and N Supply Effect on Root Mass of Two Annual Pasture Grasses
A major aim of integrated crop livestock system (ICLS) with trees is to increase the overall land productivity and/or its sustainability by making best use of the environmental resources (water, light and nutrients) used by plant for growth (Jose et al. 2008). Consequently, research efforts have been done in order to investigate the complex animal-plant-soils interactions operating upon the biological production of these systems, and their environmental impacts. For instance, since roots return to soil as a stock of C in the soil is in general larger than shoot return, interest in describing plant root system has increased due the current debate over sequestration of C by vegetation. Therefore, an important issue of ICLS is the degree of competition or, conversely, the complementary level that exists between root development and root system activities (Gregory 2006). However, our knowledge about the mechanisms by which biomass allocation (aerial parts of the plant vs. root system) is regulated is poor (Poorter et al. 2011), mainly when considering simultaneous stresses (e.g. light and nutrients). In the present study we report the shoot:root ratio and root mass variation responses to N fertilization levels of two forage grass species growing in field situation under a tree canopy while grazed by beef heifers versus an open, treeless ICLS
Goat incubator: can bovine oocytes be matured in the uterine horn of a goat?
Abstract We used a goat as a live incubator, along with associated nonsurgical embryo transfer techniques, to perform ex situ (in vivo) maturation of bovine oocytes. Immature bovine cumulus-oocyte complexes (COCs) aspirated from 3-8 mm follicles from slaughterhouse ovaries were randomly split into two groups for in vitro (IVM; n = 38) and ex situ maturation (ESM; n = 40). IVM was performed for a period of 24 h at 38.5 ºC and with 5% CO2 in the air of maximum humidity. For ESM, a presynchronized nulliparous goat (12 months old) received 40 immature COCs in the uterine horn apiece, via the transcervical route. After 24 h the structures were retrieved through uterine flushing. Analyses of nuclear maturation and lipid quantification were performed on oocytes from both groups. Fluorescent intensity was compared using the Student?s t-test. Forty-seven percent of the structures were recovered after uterine flushing (19/40). The nuclear maturation rate was 94.5% (18/19) and 81.6% (31/38) for the ESM and IVM groups, respectively. In vitro-matured COCs contained more lipid droplets, expressed as a higher amount (p < 0.05) of emitted fluorescent light than ex situ-matured COCs (858 ± 73 vs. 550 ± 64 arbitrary fluorescence units, respectively). This is the first report to associate nonsurgical embryo transfer techniques and a goat as a live incubator for the maturation of bovine oocytes. We conclude that bovine oocytes can progress meiotically in the uterus horn of a goat and that transcervical transfer of bovine oocytes to a goat?s uterus could present an alternative to nuclear maturation
Goat incubator: the doe as a life incubator of bovine oocytes - first step.
Despite significant improvements in the in vitro production of cattle embryos, the suboptimal in vitro culture environment still limits the embryo quality and production. Techniques that associate the advantages of in vivo and in vitro systems, such as intrafollicular transfer of immature oocytes, have been proposed mainly to increase the embryo quality. In this context, we tried to use a goat as live incubator and associated nonsurgical embryo transfer techniques in small ruminants to perform ex situ (in vivo) maturation of bovine oocytes. For this, immature bovine cumulus-oocyte complexes (COCs) of grade 1 and 2 were randomly distributed into two groups for in vitro (IVM; n = 38) and ex situ (ESM; n = 40) maturation. The IVM was performed for a period of 24 h in TCM-199 medium (Gibco Life Technologies, Inc., Grand Island, NY, USA) supplemented with 20 mg/mL of FSH (Pluset, Calier, Barcelona, Spain), 0.36 mM sodium pyruvate (Sigma Chemical, St. Louis, MO, USA), 10 mM sodium bicarbonate (Sigma Chemical, St. Louis, MO, USA) and 50 mg/mL streptomycin/penicillin (Sigma Chemical, St. Louis, MO, USA) at 38.8 ºC in an atmosphere of 5% CO2 in air with maximum humidity. For ESM, a pre-synchronized nulliparous goat (12 months old) received 40 immature COCs in the uterine horn apice by transcervical route (Fonseca et al., 2014 Arq. Bras. Med.vet. Zootec) and 24 h after the procedure the structures were retrieved by the uterine flushing (Fonseca et al., 2013 Small Rumin Res). For analysis of the nuclear maturation rate and lipid quantification, the oocytes were denuded (0.1% hyaluronidase), fixed (4% paraformaldehyde) and stained with 10 ?g/mL Hoechst 33342 and 10 ?g/mL Nile Red (Molecular Probes, Inc., Eugene, OR, USA) dissolved in physiological saline (0.9% NaCl) with 1mg/mL polyvinylpyrrolidone. Oocytes displaying metaphase II plate were considered matured. The lipid amount was inferred by measuring the fluorescence intensity using the ImageJ program and fluorescence intensity were compared by Student's t-test. Forty-seven percent of the structures were recovered after uterine flushing (19/40). The nuclear maturation rate was 94.5% (18/19) and 81.6% (31/38) for ESM and IVM groups, respectively. In vitro-matured oocytes contained more lipid droplets, expressed as a higher (p < 0.05) amount of emitted fluorescence light (858 ± 73 arbitrary fluorescence units) than ex situ-matured oocytes (550 ± 64 arbitrary fluorescence units). This is the first report associating nonsurgical embryo transfer techniques with goat as live incubator for maturation of bovine oocytes. We conclude that transcervical transfer of bovine oocytes to uterine goat may be an alternative to in vitro maturation aiming the reduction of lipids without compromising nuclear maturation. Further studies are required to improve the oocyte recovery rate.Proceedings of the 31st Annual Meeting of the Brazilian Embryo Technology Society (SBTE); Cabo de Santo Agostinho, PE, Brazil, August 17th to 19th, 2017. Abstracts
Dinâmica dos campos da Campanha, fronteira Oeste e Missões do Rio Grande do Sul.
Os Campos representam a base da pecuária do Rio Grande do Sul. Este trabalho apresenta um mapeamento da dinâmica de cobertura vegetal dos campos com potencial de utilização pastoril na Produção Pecuária nas regiões da Campanha, Missões e Fronteira Oeste do RS.Zootec. Autor publicado como Danilo da Serra Rocha
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