Navegando por Assunto "Pastagem"

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Acesso aberto (Open Access)
Alterações histológicas em fígados e linfonodos de búfalos (Bubalus bubalis) mantidos em pastagens de Brachiaria spp.
(2010-09) RIVERO, Beatriz Riet Correa; CORREA, Franklin Riet; OLIVEIRA JÚNIOR, Carlos Alberto de; CERQUEIRA, Valíria Duarte; RIVERO, Gabriela Riet Correa
Infiltration by foamy macrophages and other lesions are reported in healthy cattle held in Brachiaria spp. pastures. With the objective to study histologic lesions in the liver and mesenteric lymph nodes in buffalo in the state of Pará, samples of liver and lymph nodes of 142 buffalo Murah and 15 Nelore cattle were studied histologically. The samples were collected in an slaughterhouse and divided into groups of animals according to their origin and period of grazing Brachiaria spp. pastures. Group (G) 1 consisted of 79 buffalo from Marajó Island, raised in native pastures free of Brachiaria spp.; G2 was composed of 17 buffalo kept since birth in Brachiaria brizantha pastures; G3 was composed of 29 buffalo purchased in Marajó Island and introduced in B. decumbens pastures where they stayed for nearly 12 months; G4 consists of 17 buffalo purchased in Marajó Island and introduced in B. brizantha pastures where they stayed for nearly 18 months. G5 was composed of 15 Nelore cattle grazing B. brizantha during one year period. To assess the degree of liver injury, grades following a scale of 0 to 4 were established according to the quantity and size of groups of foamy macrophages. In G1, from the Marajó Island, there were no significant histological changes in liver and lymph nodes. Foamy macrophages and other lesions were observed in liver and lymph nodes of all samples from G1, G2, G3, and G4. The animals from G2 and G4, which remained a longer period in Brachiaria spp., showed more pronounced infiltration of foamy macrophages (P<0.05) than the animals of G3. Other lesions observed in the livers of these three groups were swollen, vacuolated or necrotic hepatocytes, mainly in the centrolobular region, and thickening of the Glisson's capsule with vacuolization and necrosis of subcapsular hepatocytes. These lesions were more pronounced in areas where exists higer infiltration of foamy macrophages. In cattle from G5 smaller groups of foamy macrophages were observed in the lymph nodes and were absent in the liver. These results suggest that the hepatic lesions observed in buffalo are caused by ingestion of Brachiaria spp. The presence of severe lesions in buffalo without clinical signs, much more severe than those observed and reported previously in cattle, as well as the low frequency of Brachiaria poisoning in buffalo grazing in Brachiaria spp. pastures, suggest that buffalo are resilient to Brachiaria spp. poisoning. In each group, there was no association between the weight at slaughter and the degree of lesion. It is also suggested that the observation of severe lesions of the liver, similar to those observed in this experiment, in animal that died from other diseases, can lead to a wrong diagnosis of Brachiaria poisoning.
Acesso aberto (Open Access)
Análise da contribuição da pecuária bovina nas mudanças de uso da terra: uma abordagem multiescala no estado do Pará.
(Universidade Federal do Pará, 2021-02-19) THALÊS, Marcelo Cordeiro; RUIVO, Maria de Lourdes Pinheiro; http://lattes.cnpq.br/9419564604488031; https://orcid.org/0000-0002-6222-5534
Brazilian Amazon has gone through a number of different economic cycles linked to the exploitation of natural resources, integrated with global markets, which have intensified since the 1960s, most recently through the ongoing expansion of agribusiness. During this process of territorial construction, land use changes have occurred heterogeneously in both space and time, with mechanisms operating at a number of different scales. The present study analyzes the shifts in land use and the contribution of cattle ranching to the process of territorial construction based on monitoring methods and indicators applied at varying scales, from the local to the regional, as a contribution to territorial management. In the Brazilian state of Pará, the study was based on the diachronic cartography of the pioneer fronts, which was used to represent and delimit the regional contrasts among these fronts. The relationship between these pioneer fronts and the dynamics of the deforestation process was also analyzed, by period, between 2002 and 2017, which allowed the territories to be classified as (i) consolidated, in which ranching is being intensified, (ii) expanding, in which the fronts are used as a strategy of occupation, and (iii) areas free of deforestation. In the municipality of Paragominas, located in a territory undergoing consolidation, the landscape dynamics were analyzed by superimposing the maps of land use with those of the agricultural aptitude of the land and the distance to the principal highways, with the aim of developing a model for the restoration of the landscape. The local landscape dynamics can be divided into two principal systems of land use, one that is based on the expansion of the pasture in valleys with sandy soils, and the other, based on mechanized farming, which is currently expanding on the clayey plateaus. The analysis of these two systems provided three important insights for the eventual restoration of the landscape. The first point is that the intensification of land use increases the pressure on the forests, principally in the areas most adequate for farming. The second is that the intensification of land use frees up areas that are inadequate for mechanization, and could potentially be used for the restoration of the forest. The third point is that local governance should be employed to define spatially explicit policies capable of transforming the landscape. In the areas sampled, in southeastern Pará, observations were conducted at specific points for visual description of the characteristics of the pasture, which were used to construct a typology of the process of pasture degradation. When this pasture typology is related to the vegetation indices (NDVI, EVI-2, NDII-5, NDII-7) extracted from Landsat 7 (ETM+) images, it can be noted that the well-formed pasture, which is associated with a reduction in the cover and height of the vegetation, was also related to a reduction in the vegetation indices. In degraded and degrading pasture, there was a lack of precision in the differentiation of the well-formed pasture. The degraded pastures or those undergoing biological degradation were identified better, but still imprecisely in comparison with the well-formed pasture with low vegetation cover, whereas the pasture undergoing agricultural degradation was confused with the well-formed pasture with a medium to high percentage of vegetation cover. This approach has considerable potential for the monitoring of areas of pasture, but needs to be refined. The analyses at different scales reflect the importance of understanding shifts in land use during the process of territorial construction, with the primary objective of transforming this knowledge into an easily-understood diagnostic tool that should facilitate adequate decision-making.
Acesso aberto (Open Access)
Áreas prioritárias para inclusão de componente arbóreo: as áreas de proteção permanente em sistemas pecuários de São Domingos do Araguaia-PA (Brasil)
(Universidade Federal de Santa Maria, 2022) FERNANDES, Igor Luiz Cunha; MANESCHY, Rosana Quaresma; SOARES, Daniel Araújo Sombra; LOPES, Claudio Henrique Sampaio
Regarding the historical process of land use and cover in Brazil, there is the degradation of native vegetation in the called permanent protection areas (APPs), on the banks of rivers. In Southeastern Pará, with the expansion of livestock activity over time, these areas were impacted, generating biodiversity loss and pressure on water bodies. This paper the land use and cover dynamics was analyzed in two areas in the municipality of São Domingos do Araguaia -PA to simulate the priority areas for arboreal component inclusion, aiming for the restoration of APPs in a farm and a rural settlement, if strategies of arboreal component inclusion are adopted. In both case studies, there are degraded pastures in extensive areas, driven by the expansion and intensification of traditional livestock in the region from 2004 to 2014.
Acesso aberto (Open Access)
Avaliação dos efeitos da mata ciliar sobres os fluxos hidrogeoquímicos em área de pastagem: caso das bacias hidrográficas dos igarapés do Sete e Pajeú - Paragominas (PA)
(Universidade Federal do Pará, 2006-09-22) SARDINHA, Aline Souza; SOUZA, Eliene Lopes de; http://lattes.cnpq.br/2060516413833723
It was studied the waters of uncofined aquifer and of portions of superficial drainage in the wartersheds of the Sete and the Pajeú rivers, in the municipal district of Paragominas, in the northeast of Pará. With total areas of around 150 and 45 Km2, respectively, those basins are mainly occupied by cattle areas. They are inserted in the sedimentary basin of Grajaú, occurring from the base to the top the Itapecuru formation, Ipixuna formation, Debris-Lateritic Paleogenic covering, Pleistocenic Sedimentary Covering and Alluvial Deposits. The chemistry of the water was evaluated in pasture areas, with and without preservation of the riparian forest that, although protected by law, is usually removed for several land uses. The waters of 9 monitoring wells were studied, installed in uncofined aquifer, and of 13 portions of superficial drainage placed in pasture areas and in riparian forest. The evaluated aquifer is constituted by sediments of the Ipixuna Formation, with kaolinite sandstones and mudstone kaulinic. Eight sampling campaigns were accomplished, during the dry and rainy periods in 2005. It was determined the contents of sodium, potassium, calcium, magnesium, nitrate, ammonium, sulfate, phosphate, bicarbonate and chloride, and in the Field pH, electrical conductivity, and temperature. In the waters of superficial drainage, the results indicate significant leaching of soils, evidenced by the higher the contents of nutrients. In the waters of superficial drainage concentrations of sulfate, potassium, magnesium and chloride were higher in the pasture areas. On the other hand, the contents of ammonium, nitrate, phosphate, calcium, sodium and bicarbonate were, in most case higher in an area of riparian forest, in which the main source of nutrients for the waters is the organic matter of the soil. I pastures these elements come from the either the limestone or the fertilizers used for pH correction and increasing of the soil fertility. Another source comes from the contribution of ashes, resulting from burning used to convert the original vegetation in pasture. In the freatic water, the contents of the cations and anions evaluated were, in general, higher in the pasture areas, except for the concentrations of sodium and chloride that were larger in the wells in riparian forest. Among the constituents analyzed, stood out, mainly, the concentrations of ammonium and bicarbonate, whose maximum values obtained in wells in riparian forest and pasture were, respectively, 0,81 and 17,6 mg.L-1 (ammonium) and 15,98 and 109,78 mg.L-1 (bicarbonate). When compared to the water of superficial drainage, it was verified that in the freatic waters most of the substances showed an increase in their contents in pasture areas. That 4 result is attributed to the fixation of nutrients by the riparian forest when the percolating water crosses the insaturated zone, while in the pastures the nutrients can reach the water table, once in those areas a significant retention of those substances does not happen. Most of the cations and anions analyzed showed higher concentrations in the wells of the point ST6, in the Sete river, where the area is of pasture and without riparian forest. The ions with higher contents were nitrate, ammonium and bicarbonate obtained in the dry period. For the alkalinity, pH and CE values were higher in pasture areas in the freatic waters. On the other hand, in the waters of superficial drainage, except for the pH, those parameters showed the highest values in the areas of riparian forest. Acid waters prevailed with pH between 5 and 6, although values close and even superior to 7 were obtained, attributed to the limestone used in the area and to the ashes, rich in bases, coming from the burning. In relation to the temperature, it was verified that it reflects the local average, 26,33oC. In the Pajeú watershed, the cation and anion contents were, in general, higher during the rainy period, while in the point ST6 in the basin of the Sete there was a relative increase in the contents of most of the ions analyzed during the dry period, due to the lowering of the water table and the low recharge of the aquifer. In the areas with riparian forest that effect was neglectable due to the small variations in the hydrological conditions along the year, resulting into a smaller annual variation in the depth of the water table.
Acesso aberto (Open Access)
Carbon content in Amazonian Oxisols after forest conversion to pasture
(2009-12) SILVA JÚNIOR, Mário Lopes da; DESJARDINS, Thierry; SARRAZIN, Max; MELO, Vânia Silva de; MARTINS, Paulo Fernando da Silva; SANTOS, Elaine Rodrigues; CARVALHO, Claudio Jose Reis de
Soil plays an important role in the C cycle, and substitution of tropical forest by cultivated land affects C dynamic and stock. This study was developed in an area of expansion of human settlement in the Eastern Amazon, in Itupiranga, State of Pará, to evaluate the effects of native forest conversion to Brachiaria brizantha pasture on C contents of a dystrophic Oxisol. Soil samples were collected in areas of native forest (NF), of 8 to 10 year old secondary forest (SF), 1 to 2 year old SF (P1–2), 5 to 7 year old SF (P5–7), and of 10 to 12 year old SF (P10–12), and from under pastures, in the layers 0–2, 2–5 and 5–10 cm, to evaluate C levels and stocks and carry out separation of OM based on particle size. After deforestation, soil density increased to a depth of 5 cm, with greater increase in older pastures. Variation in C levels was greatest in the top soil layer; C contents increased with increasing pasture age. In the layers 2–5 and 5–10 cm, C content proved to be stable for the types of plant cover evaluated. Highest C concentrations were found in the silt fraction; however, C contents were highest in the clay fraction, independent of the plant cover. An increase in C associated with the sand fraction in the form of little decomposed organic residues was observed in pastures, confirming greater sensitivity of this fraction to change in soil use.
Acesso aberto (Open Access)
Crédito e pecuária bovina leiteira em assentamentos da reforma agrária em Marabá-Pará
(Universidade Federal do Pará, 2012-02-29) PEREIRA, Taynã Zandely da Silva; MARTINS, Paulo Fernando da Silva; http://lattes.cnpq.br/3223618156268542
The agrarian changes occurred in the Amazon region after the settlements and programs creation to support family farmers deserve to be addressed, especially the implications they have in the expansion of pastures and increased deforestation on the one hand, and the expectation that these changes may influence farmers to stay in the same area keeping their production systems. This work presents research results of two settlements of Agrarian Reform located in the town of Maraba-Para at different historical contexts. Relationships between rural credits, implantation of pasture and cattle activity were analyzes. It also evaluates the current situation and prospects of farmers who develop this activity remain on their lots. Uses observation in loco, surveys and interweaver and statistical comparisons to compare groups of establishments with and without credit, with or without the sale of milk, and to assess the differences between indicators of deployment pasture and livestock activities to identify which variables best justify the progress of implementation of pastures as well as of production, productivity and the sale of milk. The increase of pastures implantation is more closely linked to size farm and the time elapsed from first implantation of pasture and less of the credit, but milk production is higher when credit is present. The expansion of livestock by establishment of agrarian reform is hampered by the extensive form of development of this activity, which weakens the perspective of farmers remain on their lots with implications with advancement upon new forested areas and the rural exodus.
Acesso aberto (Open Access)
Fotossensibilização hepatógena em eqüinos pela ingestão de Brachiaria humidicola (Gramineae) no estado do Pará
(2006-09) BARBOSA NETO, José Diomedes; OLIVEIRA, Carlos Magno Chaves; TOKARNIA, Carlos Maria Antônio Hubinger; PEIXOTO, Paulo Fernando de Vargas
Data on the clinical-pathological aspects and on the epidemioloy of a disease in horses, characterized by phototsensitization, which occurs in northeastern of Pará, Brazil, are presented. Of a total of 40 horses examined clinically, post-mortem examination was performed on seven. Due to the characteristic lesions found on the non-pigmented skin, the macroscopic and histological alterations in the liver, and knowing that Brachiaria grasses contain saponins with toxic properties, which cause liver lesions and photosensitization in cattle and sheep, it is concluded that this disease in horses is caused by grassing exclusively Brachiaria humidicola.
Acesso aberto (Open Access)
Massa de forragem e dieta selecionada por bovinos em pastagens cultivadas e consorciadas com leguminosas, estabelecidas com e sem queima da vegetação secundária
(Universidade Federal do Pará, 2006-02-24) GUIMARÃES, Andréa Krystina Vinente; CAMARÃO, Ari Pinheiro; http://lattes.cnpq.br/1649891765946593
It was carried out a study in the city of Igarapé-açú, Pará State, Brazil, with the objective to evaluate the mass of forage and botanical composition of bovine diet on pasture of braquiarão grass and quicuio grass, with the association of legums Arachis pintoi, Cratylia argentea and Leucaena leucocephala with and without burning of the secondary vegetation. The area was divided into plots, with three repetitions. Two experiments were realized, one with burning and another with mulching. Three pastures were tested for each experiment: 1. QB - B. humidicola + B. brizantha cv. Marandu. 2. QBAL - B. humidicola + B. brizantha + A. pintoi cv. Amarilo + L. leucocephala cv. Cunninghan . 3. QBAC - B. humidicola + B. brizantha + A. pintoi cv. Amarilo + C. argentea. The diet composition consumed by the animals was estimated through microhistological analysis of feces. The experiments took place from April 15th of 2002 to the 18th of March of 2003. The feces and mass of forage collects were performed every eighteen days. The samples of forage were taken at random, in the plots of grasses six places were sampled, while in the consorted plots twelve places were sampled. The data of forage mass and botanical composition of the diet were evaluated through software SAS 8.0. There were seasonal differences in the total mass, braquiarão’s leaf mass, araquis’, capoeira’s species and dead material. As to the methodology of area preparation, all the response variables showed differences. The total mass, leaf and stem of braquiarão and dead material were greater in the pasture of grasses (QB). The mass of leaf and stem of quicuio and araquis’ were greater in the pasture of QBAL and the mass of capoeira’s species was greater in the pasture of QBAC. All the variables presented significant differences between cycles, and the greater total masses were obtained in cycles three and four. The consumption of quicuio and capoeira’s species were greater in the dry season, while, the percentage of braquiarão was greater in the rainy season. The percentages of quicuio were greater with the burning method, while the braquiarão’s were greater in the mulch method. There were not significant differences among the pastures as to the quicuio’s percentages and capoeira’s species. The braquiarão’s percentages were greater in the pastures of QB and QBAL and the legums’s were greater in the consorted pastures with legums of QBAC and QBAL. 14 families and 23 species were found. The methodology of area preparation influenced the forage’s mass and botanical composition of the animal’s diet. The botanical composition of the diet was influenced by the forage’s mass. Capoeira’s species had a little participation in the botanical composition of the animal’s diet due to sufficient availability of forage in most parts of the year.
Acesso aberto (Open Access)
Níveis de fósforo, cobre, cobalto e zinco em bubalinos (Bubalus bubalis) na Ilha de Marajó, Estado do Pará
(2011-03) PINHEIRO, Cleyton Prado; BOMJARDIM, Henrique dos Anjos; ANDRADE, Stefano Juliano Tavares de; FAIAL, Kelson do Carmo Freitas; OLIVEIRA, Carlos Magno Chaves; BARBOSA NETO, José Diomedes
The study comprised 104 adults buffaloes, without distinction of race and sex, reared extensively, without supplementation, in native pastures of low nutritional quality, in the municipalities of Breves, Cachoeira do Arari, Salvaterra and Soure, Marajo Island, Pará. Samples of liver, bone and blood were collected from 26 animals in the municipality of Salvaterra, from 38 animals in the municipality of Soure, from 20 animals in the municipality of Breves and from 20 animals in the municipality of Cachoeira do Arari. Determination of the levels of phosphorus in the blood serum and bone ash, and of the specific gravity of bone, and of cobalt, copper and zinc in liver tissue were performed. The average phosphorus concentrations in blood serum (6.26mg/dl) and bone (10.77%), the percentage of ash (60.87%) and specific gravity (1.59g/ml) of bone were lower than the critical levels established for cattle, characterizing phosphorus deficiency. The average concentrations of copper (5.57ppm) and zinc (27.05ppm) was considered low when compared with reference values, characterizing deficiency for these elements. In the case of cobalt when considering the detectable and undetectable values by the methodology, it was observed that 51.92% of the animals had levels below the reference, indicating the occurrence of cobalt deficiency in these animals. It is emphasized that the deficiencies of copper and zinc were the most severe since all animals studied showed deficient levels of these elements.
Acesso aberto (Open Access)
Queilite angular traumática em eqüinos associada à ingestão de Panicum maximum
(2009-05) BARBOSA NETO, José Diomedes; ALBERNAZ, Tatiane Teles; RIVERO, Gabriela Riet Correa; CERQUEIRA, Valíria Duarte; SOARES, Susiane de Oliveira; CAMPOS, Karinny Ferreira; OLIVEIRA, Carlos Magno Chaves; DUARTE, Marcos Dutra
A condition with enlargement of the oral cleft in horses was studied. The enlargement of varied extension was uni or bilateral. The cheek mucosa of the labial commissure showed slight erosions. During chewing there was loss of small amounts of grass and saliva through the oral cleft. The affected horses were in good nutritional condition. Histopathological studies of tissues obtained by biopsia, revealed a superficial epidermitis. The pastures consisted of Panicum maximum grass (varieties Tanzânia, Mombaça, Tobiatã and Colonião) which was mature, tall, lignified, with leaves of cutting edges. Based on epidemiological, clinical and histopathological data, it was concluded that the lesions were caused by the hard grass, favored by the way horses pull the tall grass and chew it.
Acesso aberto (Open Access)
Respostas termorregulatórias e comportamentais de fêmeas bubalinas criadas a pasto, em condições de ambiente do trópico úmido
(Universidade Federal do Pará, 2015-09-11) BRCKO, Carolina Carvalho; LOURENÇO JÚNIOR, José de Brito; http://lattes.cnpq.br/2919433679918544
Testing the thermoregulatory and behavior responses in buffalo in the eastern Amazon, three experiments were conducted at Embrapa Amazônia Oriental (01 ° .26'.03 "S and 48 ° .26'.03" W) in the period July 2013 to June 2014, with 24 buffaloes crossbred Murrah / Mediterranean. That were in paddocks with Brachiaria brizantha (cv. Marandu) in a rotational system with drinking water and mineral salt at will. Experiment 1 aimed to evaluate the effects of climate and the inclusion of four levels (0, 0.25, 0.5 and 1% of PV) of palm kernel cake in thermoregulation of buffaloes. Air temperature data were recorded (AT), relative humidity (RH), dew point temperature, wet bulb temperature, black globe temperature (BGT), rectal temperature (RT), temperature of the body surface (TBS), respiratory rate (RR). Daily, animals received food into individual troughs and the diet was adjusted by reweighing of animals every 28 days. It was concluded that there is no effect of palm kernel cake on thermoregulation of buffaloes. The second experiment aimed to study the exchange capacity and daily heat preservation buffaloes and lasted six days. Physiological (RT, RR and TBS by infrared thermography) and climate (TA, UR, TG) at 6:00 am, 9:00 am, 12:00, 15:00, 18:00 and 21:00. Although exposed to adverse weather conditions, the buffalo are able to return to homeostasis in the evening, indicating that the species has great adaptive capacity. Finally, the experiment 3 aimed to study the inclusion of palm kernel cake, at different levels (0, 0.25, 0.5, 1% of PV) is able to change the behavior of buffalo raised on pasture. The experiment was conducted in two seasons (wettest and less rain). Climate variables are as described in experiment 1. The behavioral analysis (grazing, ruminating, leisure and other activities) was carried out between 6:00 a.m. and 18:00 for three consecutive days in each collection campaign. 24 buffaloes were used, six for each treatment. The test diet does not influence the buffalo behavior. Despite suffering physiological and behavioral changes due to the effect of environmental variables, especially in the period with higher temperatures, buffaloes showed its ability to return to homeostasis as the temperature became milder, indicating great adaptive capacity.
Acesso aberto (Open Access)
Sistemas agroflorestais pecuários: o uso de espécies arbóreas como alternativa para o redesenho da paisagem rural e reabilitação de pastagens degradadas em São Domingos do Araguaia - PA
(Universidade Federal do Pará, 2020-12-15) FERNANDES, Igor Luiz Cunha; LOPES, Luis Otávio do Canto; http://lattes.cnpq.br/1013147545099173; MANESCHY, Rosana Quaresma; http://lattes.cnpq.br/5914095913079907
The research aimed to generate models of livestock agroforestry systems that can contribute to the redesign of the rural landscape and local development in southeastern Pará. The research was carried out from 2018 to 2020 in the municipality of São Domingos do Araguaia - PA. Tree species with the potential to integrate livestock agroforestry systems in different types of arrangements were selected according to local specificities based on bibliographic research and a field experiment that analyzed the management, production of nutritional quality of the species tested, namely: Gliricidia sepium (Jacq.) Walp., Guazuma ulmilifolia Lam., Albizia saman (Jacq.) F. Muell., Erythina glauca Willd. and Chloroleucon tortum (Mart.) Pittier ex Barneby & JW Grimes. From the results, the models of eligible arrangements were simulated, according to the biophysical characteristics of the location. The research also simulated the redesign of the rural landscape on a farm and a settlement in the municipality of São Domingos of Araguaia in the case of adopting strategies for incorporating the tree component in the rural landscape to restore the permanent protection area. Based on the results of the research, agroecological records on species and arrangements were prepared to support the work of rural technical assistance in the municipality to adopt these systems.