Virgilio Mesquita Gomes

Características morfogênicas e estruturais de perfilhos de capim-braquiária em locais do pasto com alturas variáveis

The objective of this experiment was to evaluate the influence of natural variation of heights of plants on the same pasture on the morphogenic and structural characteristics of Brachiaria decumbens cv. Basilisk managed under continuous stocking with cattle. Four plant heights (10, 20, 30 and 40 cm) were evaluated on the same pasture managed at an average height of 25 cm. It was used a randomized block design with two replications. Leaf appearance rate of signalgrass was linearly and negatively influenced by heights of the plants on the same pasture. The tillers on the same sites with the highest heights showed greater phyllochron (9.3 days). The higher plant heights on the same pasture promoted both higher leaf senescence and pseudoculm elongation rates for the tillers. Leaf lifespan (37.8 days) and leaf elongation rate (1.3 cm/tillers.day) were not influenced by the plant height. The number of green (4.36) and dead (2.15) leaves was not changed by the plants height either. However, the higher height of plants resulted in a linear increase of 69% on the number of leaves showing defoliation. Pseudoculm and leaf blade lengths responded linearly and positively to the increase in the plants height on the same pasture. The natural height variance of plants found on the same pasture changes the morphogenetic and structural characteristics of signalgrass. There is spatial variability of the vegetation on Brachiaria decumbens cv. Basilisk pastures managed under continuous stocking with bovine.

Capim-braquiária sob lotação contínua e com altura única ou variável durante as estações do ano: morfogênese e dinâmica de tecidos

Este trabalho foi realizado com o objetivo de identificar estrategias eficazes de manejo do pastejo de Brachiaria decumbens cv. Basilisk, sob lotacao continua, com base em avaliacoes das suas caracteristicas morfogenicas e estruturais. Duas estrategias de manejo do pastejo foram estudadas: em uma, o pasto foi mantido com 25 cm de altura media durante todo o periodo experimental e, na outra, foi mantido em 15 cm de altura media durante o inverno, com aumento para 25 cm a partir do inicio da primavera. Adotou-se o delineamento de blocos casualizados em esquema de parcelas subdivididas com quatro repeticoes. Consideraram-se, como fator primario, as estrategias de manejo do pastejo, caracterizadas pelas alturas medias dos pastos durante as estacoes do ano (inverno, primavera e verao), e, como fator secundario, as estacoes. O rebaixamento do pasto para 15 cm no inverno resultou em maior taxa de aparecimento foliar (0,02 folha/perfilho.dia) e maior numero de folhas vivas (4,5 folhas por perfilho) no inverno, mas provocou reducao, no inverno, da duracao de vida da folha (66 dias), da taxa de senescencia foliar (0,22 cm/perfilho.dia) e dos comprimentos da lâmina foliar (11 cm) e pseudocolmo (15,2 cm) em relacao ao pasto com 25 cm. Nesta estacao, foram menores os valores observados para as taxas de aparecimento foliar (0,06 folha/perfilho.dia), alongamento foliar (0,110 cm/perfilho.dia) e alongamento de pseudocolmo (0,008 cm/perfilho.dia), numero de folha viva (2,9 folhas por perfilho) e comprimentos da lâmina foliar (8,6 cm) e do pseudocolmo (13,5 cm). Por outro lado, a duracao de vida da folha (139 dias) e o numero de folhas mortas (2,0 folhas por perfilho) foram maiores. O maior valor de taxa de senescencia foliar ocorreu na primavera (0,40 cm/perfilho.dia). O pasto de B. decumbens cv. Basilisk sob lotacao continua pode ser manejado de forma sazonal, com rebaixamento para 15 cm no inicio do inverno e posterior aumento para 25 cm no inicio da primavera.Este trabalho foi realizado com o objetivo de identificar estrategias eficazes de manejo do pastejo de Brachiaria decumbens cv. Basilisk, sob lotacao continua, com base em avaliacoes das suas caracteristicas morfogenicas e estruturais. Duas estrategias de manejo do pastejo foram estudadas: em uma, o pasto foi mantido com 25 cm de altura media durante todo o periodo experimental e, na outra, foi mantido em 15 cm de altura media durante o inverno, com aumento para 25 cm a partir do inicio da primavera. Adotou-se o delineamento de blocos casualizados em esquema de parcelas subdivididas com quatro repeticoes. Consideraram-se, como fator primario, as estrategias de manejo do pastejo, caracterizadas pelas alturas medias dos pastos durante as estacoes do ano (inverno, primavera e verao), e, como fator secundario, as estacoes. O rebaixamento do pasto para 15 cm no inverno resultou em maior taxa de aparecimento foliar (0,02 folha/perfilho.dia) e maior numero de folhas vivas (4,5 folhas por perfilho) no inverno, mas provocou reducao, no inverno, da duracao de vida da folha (66 dias), da taxa de senescencia foliar (0,22 cm/perfilho.dia) e dos comprimentos da lâmina foliar (11 cm) e pseudocolmo (15,2 cm) em relacao ao pasto com 25 cm. Nesta estacao, foram menores os valores observados para as taxas de aparecimento foliar (0,06 folha/perfilho.dia), alongamento foliar (0,110 cm/perfilho.dia) e alongamento de pseudocolmo (0,008 cm/perfilho.dia), numero de folha viva (2,9 folhas por perfilho) e comprimentos da lâmina foliar (8,6 cm) e do pseudocolmo (13,5 cm). Por outro lado, a duracao de vida da folha (139 dias) e o numero de folhas mortas (2,0 folhas por perfilho) foram maiores. O maior valor de taxa de senescencia foliar ocorreu na primavera (0,40 cm/perfilho.dia). O pasto de B. decumbens cv. Basilisk sob lotacao continua pode ser manejado de forma sazonal, com rebaixamento para 15 cm no inicio do inverno e posterior aumento para 25 cm no inicio da primavera.

Influência da localização das fezes nas características morfogênicas e estruturais e no acúmulo de forragem em pastos de capim-braquiária

The objective of this study is to evaluate morphogenetic and structural characteristics as well as forage accumulation on Brachiaria decumbens pastures according to the site of cattle feces. It was evaluated two grazing areas: near and far from the droppings. The design used was a random block design, with three replicates. Tillers were tagged on the pasture for evaluation of length of the leaves and stems. Leaf appearance and death were also recorded. Stem elongation rate was 80% higher and leaf elongation rate was 23% higher for the tillers near the dropping areas. Phyllochron was also higher for tillers (8.5 days) in sites close to the feces in comparison to those from the distant areas (7.7 days). There was no effect of dropping localization on leaf senescence rate (0.39 cm/tiller.day) and leaf life span (38 days). Final leaf blade length was 25% higher for tillers near the droppings. The number of defoliating leaves (1.3 leaf) was lower in areas near the droppings, contrary to the number of dead leaves (2.8 leaves). Pseudostem length increased 73% as it was closer to the droppings. Number of dead and total vegetative tiller was higher in areas far from the droppings. Higher total growth rate of B. decumbens also occurred in sites close to the droppings. Cattle droppings change the morphogenetic characteristics and structure of B. decumbens pasture. In areas close to the feces, the tissue flow is more intense and forage accumulation is higher.

Forage accumulation in brachiaria grass under continuous grazing with single or variable height during the seasons of the year

The objective of this study was to evaluate grazing management strategies of Brachiaria decumbens cv. Basilisk managed with different heights under continuous grazing with cattle. Two grazing management strategies were evaluated: maintenance of pasture with an average height of 25 cm throughout the experimental period and maintenance of pasture on the average of 15 cm in height during winter, up to 25 cm from the beginning of spring. The split-plot scheme and the randomized block design with four replications were adopted. The grazing management strategies corresponded to the primary factor, while the seasons (winter, spring and summer) corresponded to secondary factor. The reduction of the average sward height to 15 cm in the winter resulted, when compared with pasture maintained at 25 cm, in overall higher growth rates (95 kg/ha.day DM) and leaf blade (66.1 kg/ha.day DM), as well as higher rates of total accumulation (81.5 kg/ha.day DM) and leaf blade (52.6 kg/ha.day DM). The accumulated forage production (from winter to summer) was higher in the pasture lowered to 15 cm in winter (25.6 t/ha DM) compared with that managed with an average height of 25 cm (22.2 t/ha DM). Regarding the seasons of the year, in the winter, there were lower rates of overall growth (6.4 kg/ha.day DM), leaf blade (5.6 kg/ha.day DM) and pseudostem (0.8 kg/ha.day DM), and also lower total (-6.6 kg/ha.day DM) and leaf blade (-7.5 kg/ha.day DM) accumulation rates. In the spring there was a higher rate of leaf senescence (22.4 kg/ha.day DM). The accumulation of forage is incremented when the pasture of B. decumbens is lowered to 15 cm during the winter, and in the spring and summer, its average height is increased to 25 cm.

Capim-braquiária sob lotação contínua e com altura única ou variável durante as estações do ano: dinâmica do perfilhamento

The experiment was conducted to establish management strategies of grazing under continuous stocking that optimize the natural pattern of tillering of Brachiaria decumbens cv. Basilisk. Two strategies of grazing management were studied: in one, the grass was maintained with 25-cm mean height throughout the experimental period, and in the other, 15-cm mean height during the winter, rising to 25 cm from beginning of spring. The split-plot in randomized block design with four replications was adopted. The strategies of grazing management corresponded to primary factor, characterized by average heights of pastures during the seasons of the year (winter, spring and summer). The seasons corresponded to secondary factor and consisted of measures over experimental period. The rates of tillers appearance (4.7%), death (4.7%) and stability index (0.998) were lower in winter. During this season, however, the tiller survival rate was higher (95.3%). Compared with pastures maintained at 25 cm, those managed with 15 cm in winter had higher tiller appearance rate (34.2%) and stability index (1.065). The signalgrass flowering occurred only in the summer and with low intensity (0.5%). Optimization for renewal of tillers in B. decumbens cv. Basilisk pasture under continuous stocking occurs with its decrease to 15 cm at the beginning of winter and subsequent increase to 25 cm in early spring.

Grazing patterns on signalgrass pasture according to location of cattle feces

This study was conducted to evaluate the defoliation patterns on B. decumbens cv. Basilisk (signalgrass) tiller as a function of influence of feces deposited naturally by cattle. The signalgrass was managed with an average height of 25 cm, under continuous stocking and variable stocking rate. Interval and intensity of defoliation, grazing efficiency and forage loss were evaluated in two sites on pasture - one close and the other distant from feces. The completely randomized block design with three replications was adopted. The defoliation rate of the pasture site close to feces was 40% lower than at that distant from feces. This response pattern was similar to defoliation intensity of leaf blade. The leaf blade of the tiller close to feces also achieved lower de foliation (1.64) than that in the tiller distant from feces (3.97). The relative number of grazed leaf per tiller in the tillers distant from feces was approximately 185% higher than those close to feces. The grazing efficiency was lower in the local close to feces compared with that distant, unlike forage loss. The natural deposition of feces by cattle modifies the grazing and use patterns of B. decumbens under continuous stocking.

Hay Tifton 85 grass under nitrogen doses in different days of regrowth

The objective of this study was to evaluate the yield, nutritional value and potential ruminal degradation of Tifton 85 hay ( Cynodon spp.) harvested at four regrowth ages (28, 35, 42 and 49 days) and fertilized with two nitrogen doses (N; 100 and 300 kg N ha -1 ). The experimental design was a randomized block design, arranged in a 4 x 2 factorial scheme, with six replications each. Nitrogen fertilization increased (p < 0.05) dry matter yield and digestible dry matter production of hay and also lignin and crude protein contents. Nitrogen fertilization increased (p < 0.01) the dry matter yield and the digestible dry matter production of hay, as well as lignin (p = 0.01) and crude protein (p = 0.01). The neutral detergent fiber corrected for ash and protein (p = 0.01), acid detergent fiber (p = 0.01) and cellulose (p = 0.02) adjusted to the quadratic function regression model of the regrowth ages. For potential rumen degradability hay, it was observed quadratic effect (p = 0.01) with maximum value of 73.1% at 37 days of regrowth. Tifton 85 hay fertilized with 300 kg ha -1 of N and harvested up to 37 days of regrowth results in higher hay dry matter yield, higher crude protein content, and better dry matter rumen degradability.

RELATO DE CASO: CARACTERIZAÇÃO DO SISTEMA DE PRODUÇÃO DE GADO DE CORTE, DESENVOLVIDO POR BRASILEIROS, NA REGIÃO DO CHACO BOLIVIANO

The purpose of this work is to describe the characteristic of the beef cattle production system in Bolivia. From a scholarship that happened in a Brazilian company who provide management in livestock, during this time it was possible know a little bit about the characteristic on Bolivia livestock. In oriental region from Bolivia the Boviplan Consultoria Agropecuaria Ltda., Brazilian company with head office in Piracicaba-SP, built an office, to offer a bigger technical support for customer that have farm in Bolivia. This region is inside on biome of Bolivian Chaco that is characterized by soil extremely fertile and cheap land. These factora help to explain the favorable scenario of beef cattle found on farms that are managed by Boviplan in Bolivia.