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Effects of intensification and integration as a strategy for sustainable pasture management in Nellore beef cattle production systems: forage productivity, animal performance and feed consumption
No full textEstratégias de intensificação dos sistemas agropecuários são recomendadas para atender à crescente demanda mundial por alimentos, pois aumentam a qualidade e a produção das pastagens e o desempenho animal, diluindo as emissões de GEE pelos produtos gerados. Este estudo avaliou o efeito da intensificação em diferentes sistemas pastoris de produção de gado de corte sobre o desempenho das pastagens e dos animais. O experimento foi realizado de setembro de 2019 a setembro de 2020 na Embrapa Pecuária Sudeste, São Carlos, SP. Quarenta tourinhos da raça Nelore (375±30 kg e 22,2±0,7 meses de idade) foram distribuídos aleatoriamente em cinco diferentes sistemas (8 animais/sistema), com duas repetições de área (10 unidades experimentais), sendo: 1) pastagem irrigada de Megathyrsus maximus cv. Tanzânia sob manejo intensivo com alta lotação, sobressemeada na época seca com Avena byzantina e Lolium multiflorum (IAL); 2) pastagem de sequeiro de M. maximus cv. Tanzânia sob manejo intensivo com alta lotação (SAL); 3) pastagem de sequeiro com Urochloa brizantha cv. Marandu e Urochloa decumbens cv. Basilisk sob manejo intensivo com moderada lotação (SML); 4) sistema silvipastoril com pastagem de sequeiro de U. decumbens cv. Basilisk e árvores nativas brasileiras (350 árvores/ha) sob manejo intensivo com moderada lotação (SSP); e 5) pastagem degradada de sequeiro com mistura de U. brizantha cv. Marandu e U. decumbens cv. Basilisk sob manejo extensivo com baixa lotação (DEG). Todas as pastagens foram submetidas a ajustes na taxa de lotação pela técnica “put and take”, manejadas sob lotação contínua para DEG e rotativa para IAL, SAL, SML e SSP com ciclos de pastejo de 36 dias. Todas as pastagens, com exceção de DEG, receberam calagem, adubação corretiva com P, K, S e micronutrientes e fertilizantes. Pastagens em IAL e SAL foram fertilizadas, respectivamente, com 600 e 400 kg N-ureia/ha/ano. Pastagens em SML e SSP receberam 200 kg N-ureia/ha/ano. Os animais de todos os sistemas receberam suplementação mineral-proteica ad libitum contendo NH4NO3. Amostras das pastagens foram coletadas para avaliar a produção e qualidade da forragem. Os animais foram pesados no início do experimento e mensalmente até o momento do abate para determinação do desempenho. Marcadores (TiO2 e FDNi) foram usados durante as estações climáticas do ano para calcular o consumo e, posteriormente, a eficiência alimentar. Os dados foram analisados utilizando SAS (SAS Inc., Cary, NC, EUA), considerando efeitos fixos: os sistemas, as estações climáticas e a interação entre eles. Houve períodos caracterizados por intenso déficit hídrico, reduzindo o potencial produtivo das pastagens. Os melhores resultados das pastagens foram no sistema IAL, seguidos de SAL e SML, com melhores produções e qualidade da forragem, que aumentaram o consumo, eficiência alimentar, desempenho animal e a produtividade por área, quando comparados com SSP e DEG; resultando em melhor aproveitamento da proteína bruta fornecida (pastagem+suplemento). Devido à interação sistema∗estação do ano e ao déficit hídrico (severo) ocorrido, foi possível observar que os melhores resultados foram associados aos sistemas que apresentaram melhor produção e qualidade da pastagem, além do desempenho animal no período seco do ano.Strategies to intensify agricultural beef systems are recommended to meet the growing world demand for food, as they increase pasture quality production and animal performance, diluting GHG emissions by the products generated. This study evaluated the effect of intensification in different grazing systems of beef cattle production on pasture and animal performance. The experiment was conducted from September 2019 to September 2020 at Embrapa Southeast Livestock, São Carlos, SP. Forty Nellore bullocks (375±30 kg and 22.2±0.7 months of age) were randomly distributed in five different production systems (8 animals/system), with two area replications (10 experimental units), being: 1) intensively managed and irrigated Megathyrsus maximus cv. Tanzania pasture with a high stocking rate, overseeded in the dry season with Avena byzantina and Lolium multiflorum (IAL); 2) intensively managed rainfed Megathyrsus maximus cv. Tanzania pasture with a high stocking rate (SAL); 3) intensively managed rainfed pasture with a mix of Urochloa brizantha cv. Marandu and Urochloa decumbens cv. Basilisk with a moderate stocking rate (SML); 4) intensively managed silvopastoral system with Urochloa decumbens cv. Basilisk pasture and Brazilian native trees (350 trees/ha) with moderate stocking rate (SSP); and 5) extensively managed rainfed degraded pasture with a mixture of Urochloa brizantha cv. Marandu and Urochloa decumbens cv. Basilisk with a low stocking rate (DEG). All pastures were subjected to stocking rate adjustments by the “put-and-take” technique, managed under continuous grazing for DEG and rotational grazing for IAL, SAL, SML and SSP with grazing cycles of 36 days. All pastures, except DEG, received liming and corrective fertilization with P, K, S and micronutrients and fertilizers. Pastures in IAL and SAL were fertilized, respectively, with 600 and 400 N- urea/ha/year. Pastures in SML and SSP received 200 kg N-urea/ha/year. Animals from all systems received ad libitum mineral-protein supplement containing NH4NO3. Pasture samples were collected to assess forage production and quality. The animals were weighed at the beginning of the experiment and monthly until the time of slaughter to estimate performance. Markers (TiO2 and NDFi) were used during the seasons to estimate voluntary feed intake and, subsequently, feed efficiency. Data were analyzed using SAS (SAS Inc., Cary, NC, USA), considering the fixed effects: systems, climatic seasons of the year and the interaction between them. There were periods characterized by intense water deficit, reducing the productive potential of the pastures. The best pasture results were in IAL systems, followed by SAL and SML, with better yields and forage quality, which increasing intake, feed efficiency, animal performance and productivity per area, when compared with SSP and DEG; resulting in better use of the crude protein supplied (pasture+supplement). Due to the interaction system*season and the (severe) water deficit that occurred, it was possible to observe that the best results were associated with the systems that presented the best production and quality of the pasture, in addition to animal performances in the dry period of the year
Efeitos da intensificação e integração como estratégia para o manejo sustentável das pastagens nos sistemas de produção de bovinos de corte da raça Nelore: produtividade da forragem, desempenho animal e consumo alimentar
Get PDFEstratégias de intensificação dos sistemas agropecuários são recomendadas para atender à crescente demanda mundial por alimentos, pois aumentam a qualidade e a produção das pastagens e o desempenho animal, diluindo as emissões de GEE pelos produtos gerados. Este estudo avaliou o efeito da intensificação em diferentes sistemas pastoris de produção de gado de corte sobre o desempenho das pastagens e dos animais. O experimento foi realizado de setembro de 2019 a setembro de 2020 na Embrapa Pecuária Sudeste, São Carlos, SP. Quarenta tourinhos da raça Nelore (375±30 kg e 22,2±0,7 meses de idade) foram distribuídos aleatoriamente em cinco diferentes sistemas (8 animais/sistema), com duas repetições de área (10 unidades experimentais), sendo: 1) pastagem irrigada de Megathyrsus maximus cv. Tanzânia sob manejo intensivo com alta lotação, sobressemeada na época seca com Avena byzantina e Lolium multiflorum (IAL); 2) pastagem de sequeiro de M. maximus cv. Tanzânia sob manejo intensivo com alta lotação (SAL); 3) pastagem de sequeiro com Urochloa brizantha cv. Marandu e Urochloa decumbens cv. Basilisk sob manejo intensivo com moderada lotação (SML); 4) sistema silvipastoril com pastagem de sequeiro de U. decumbens cv. Basilisk e árvores nativas brasileiras (350 árvores/ha) sob manejo intensivo com moderada lotação (SSP); e 5) pastagem degradada de sequeiro com mistura de U. brizantha cv. Marandu e U. decumbens cv. Basilisk sob manejo extensivo com baixa lotação (DEG). Todas as pastagens foram submetidas a ajustes na taxa de lotação pela técnica “put and take”, manejadas sob lotação contínua para DEG e rotativa para IAL, SAL, SML e SSP com ciclos de pastejo de 36 dias. Todas as pastagens, com exceção de DEG, receberam calagem, adubação corretiva com P, K, S e micronutrientes e fertilizantes. Pastagens em IAL e SAL foram fertilizadas, respectivamente, com 600 e 400 kg N-ureia/ha/ano. Pastagens em SML e SSP receberam 200 kg N-ureia/ha/ano. Os animais de todos os sistemas receberam suplementação mineral-proteica ad libitum contendo NH4NO3. Amostras das pastagens foram coletadas para avaliar a produção e qualidade da forragem. Os animais foram pesados no início do experimento e mensalmente até o momento do abate para determinação do desempenho. Marcadores (TiO2 e FDNi) foram usados durante as estações climáticas do ano para calcular o consumo e, posteriormente, a eficiência alimentar. Os dados foram analisados utilizando SAS (SAS Inc., Cary, NC, EUA), considerando efeitos fixos: os sistemas, as estações climáticas e a interação entre eles. Houve períodos caracterizados por intenso déficit hídrico, reduzindo o potencial produtivo das pastagens. Os melhores resultados das pastagens foram no sistema IAL, seguidos de SAL e SML, com melhores produções e qualidade da forragem, que aumentaram o consumo, eficiência alimentar, desempenho animal e a produtividade por área, quando comparados com SSP e DEG; resultando em melhor aproveitamento da proteína bruta fornecida (pastagem+suplemento). Devido à interação sistema*estação do ano e ao déficit hídrico (severo) ocorrido, foi possível observar que os melhores resultados foram associados aos sistemas que apresentaram melhor produção e qualidade da pastagem, além do desempenho animal no período seco do ano.Strategies to intensify agricultural beef systems are recommended to meet the growing world demand for food, as they increase pasture quality production and animal performance, diluting GHG emissions by the products generated. This study evaluated the effect of intensification in different grazing systems of beef cattle production on pasture and animal performance. The experiment was conducted from September 2019 to September 2020 at Embrapa Southeast Livestock, São Carlos, SP. Forty Nellore bullocks (375±30 kg and 22.2±0.7 months of age) were randomly distributed in five different production systems (8 animals/system), with two area replications (10 experimental units), being: 1) intensively managed and irrigated Megathyrsus maximus cv. Tanzania pasture with a high stocking rate, overseeded in the dry season with Avena byzantina and Lolium multiflorum (IAL); 2) intensively managed rainfed Megathyrsus maximus cv. Tanzania pasture with a high stocking rate (SAL); 3) intensively managed rainfed pasture with a mix of Urochloa brizantha cv. Marandu and Urochloa decumbens cv. Basilisk with a moderate stocking rate (SML); 4) intensively managed silvopastoral system with Urochloa decumbens cv. Basilisk pasture and Brazilian native trees (350 trees/ha) with moderate stocking rate (SSP); and 5) extensively managed rainfed degraded pasture with a mixture of Urochloa brizantha cv. Marandu and Urochloa decumbens cv. Basilisk with a low stocking rate (DEG). All pastures were subjected to stocking rate adjustments by the “put-and-take” technique, managed under continuous grazing for DEG and rotational grazing for IAL, SAL, SML and SSP with grazing cycles of 36 days. All pastures, except DEG, received liming and corrective fertilization with P, K, S and micronutrients and fertilizers. Pastures in IAL and SAL were fertilized, respectively, with 600 and 400 N-urea/ha/year. Pastures in SML and SSP received 200 kg N-urea/ha/year. Animals from all systems received ad libitum mineral-protein supplement containing NH4NO3. Pasture samples were collected to assess forage production and quality. The animals were weighed at the beginning of the experiment and monthly until the time of slaughter to estimate performance. Markers (TiO2 and NDFi) were used during the seasons to estimate voluntary feed intake and, subsequently, feed efficiency. Data were analyzed using SAS (SAS Inc., Cary, NC, USA), considering the fixed effects: systems, climatic seasons of the year and the interaction between them. There were periods characterized by intense water deficit, reducing the productive potential of the pastures. The best pasture results were in IAL systems, followed by SAL and SML, with better yields and forage quality, which increasing intake, feed efficiency, animal performance and productivity per area, when compared with SSP and DEG; resulting in better use of the crude protein supplied (pasture+supplement). Due to the interaction system*season and the (severe) water deficit that occurred, it was possible to observe that the best results were associated with the systems that presented the best production and quality of the pasture, in addition to animal performances in the dry period of the year
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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