Newton de Lucena Costa

Tolerância de Bovídeos à Temperatura e Umidade do Trópico Úmido

O objetivo deste trabalho foi avaliar os efeitos do clima sobre a temperatura retal (TR) e frequencia respiratoria (FR), alem de determinar o indice de tolerância ao calor (ITC) de bovinos e bubalinos durante 0 verao de tropico umido. Foram utilizadas seis vacas Girolanda e seis bufalas mesticas Murrah x Mediterrâneo, mantidas em curral a ceu aberto, onde recebiam agua, sal mineral, capim-elefante, cana-de-acucar e racao (milho, mandioca e soja). Os parâmetros fisiologicos foram medidos pela manha e a tarde. A analise da variância revelou diferencas significativas (P 0,05) quanto a horario em relacao as especies, sendo a TR (39,11 e 39,26 o C) de bovinos e bubalinos pela tarde superiores as da manha (38,10 e 38,05 o C). A FR foi significativamente menor pela manha, em relacao a tarde, cujos resultados medios foram 36,00 e 58,91 mov/min para bovinos e 35,31 e 58,33 mov/min para bubalinos. O ITC observado nao apresentou diferencas significativas entre as especies.

Avaliação Agronômica de Variedades de Cana-de-Açúcar para Fins Forrageiros em Rondônia

The agronomic performance of sugarcane varieties (RB 72-454, RB 78- 5148, RB 73-9735, RB 73-9359, RB 83-5486, SP 71-1406, SP 79-1011, CB 45-3, CB 47-355, NA 56-79 and test) introduced in Rondonia - Brazil was evaluated. It was used a randomized blocks design, with three replications. The plantation was carried out in November of 1999 and the harvesting occurred in June of 2001. The plants presented average height of 3,69 m. The RB 83- 5486 presented smaller height and RB 73-9359 was higher than another varieties. RB 78-5148 presented the largest DM content and RB 72-454 the smallest (P 0.01). The average yield of GM and DM were of 208 and 55 t/ ha, respectively, with RB 73-9735 reaching the largest ones, not being different of RB 72-454, RB 78-5148, RB 71-1406, SP 79-1011, CB45-3, CB 47-355 and NA 56-79 (P>0.01). The plants showed average values of 88.0, 7.0, 4.0 and 1.0% of stems, tip, green and dry leaves, respectively. The varieties RB 73-9735, RB 78-5148, RB 73-9359 and CB 47-355 where presented the best general performance, with regard to forage production, sugar content and steam participation.

Forage productivity and morphogenesis of Axonopus aureus under different nitrogen fertilization rates

) on forage yield and morphogenesis of Axonopus aureus was evaluated in the savannas of Roraima State, Brazil. The experimental design was in randomized blocks with three replicates. The grass showed high responsiveness to N fertilization. Dry weight (DW) yield, morphogenetic and structural traits and forage quality were positively affected by N fertilization. The effects of N fertilization on DW yield, N content, leaf appearance rate, leaf elongation rate, number of live leaves/tiller, final leaf length and leaf area index were quadratic and maximum values were estimated with application of 168.8 (2,181 kg ha -1 ); 124.8 (21.1 g/kg); 158.5 (0.163 leaf/day per tiller); 172.3 (2.75 cm/tiller per day); 155.5 (17.23 cm); 185.5 (7.55 leaves/tiller) and 185.3 (2.22) kg N ha -1 , respectively. Tiller population density and leaf senescence rate are directly proportional to increase in N rates, and the opposite occurs for N utilization efficiency and apparent N recovery.

Produtividade de Forragem e Morfogênese de Trachypogon plumosus sob Diferentes Níveis de Desfolhação

O efeito de niveis de desfolhacao (5, 10, 15, 20, 25 e 30 cm acima do solo) sobre a producao de forragem e caracteristicas morfogenicas e estruturais de Trachypogon plumosus foi avaliado nos cerrados de Roraima. Os efeitos dos niveis de desfolhacao sobre a producao de materia seca, numero de folhas/perfilho, tamanho medio de folhas, area foliar e taxas de aparecimento e expansao de folhas foram quadraticos e os maximos valores registrados com cortes a 22,3; 19,7; 25,9; 23,4; 21,5 e 22,4 cm acima do solo, respectivamente. A densidade populacional de perfilhos foi diretamente proporcional ao nivel de desfolhacao, ocorrendo o inverso quanto a taxa de senescencia foliar. A eliminacao de meristemas apicais foi incrementada com o aumento do nivel de desfolhacao. O vigor de rebrota foi direta e negativamente correlacionado com o nivel de desfolhacao. DOI: 10.15528/2176-4158/rcpa.v14n2p169-172

Características morfogênicas e estruturais de Trachypogon plumosus de acordo com a fertilidade do solo e o nível de desfolha

The objective of this work was to evaluate the effects of growing seasons, liming, fertilization, and defoliation levels on morphogenetic and structural traits of Trachypogon plumosus in the savanna of the state of Roraima, Brazil. The following treatments were evaluated: correction of soil fertility (control, liming, fertilization, and liming + fertilization), defoliation levels (removal of 50 and 75% of the leaves), and growing seasons (rainy and dry). The grass positively responded to the correction of soil fertility. Fertilization and liming + fertilization, during the rainy season, provided higher leaf appearance rates (LApR), leaf elongation rates, number of live leaves (NLL), leaf lifespan, final leaf length (FLL), leaf area index (LAI), and tiller population density (TPD), besides a lower phyllochron. The evaluated variables were significantly reduced during the dry season, except for leaf senescence rate. The lowest defoliation level positively affected LApR, FLL, and LAI, but not NLL and TPD. The management with lower defoliation level maximizes the harnessing of environmental resources and forage use efficiency.

Casca de Café na Alimentação de Ovinos Deslanados

Para avaliar o desempenho de ovinos deslanados em crescimento, alimentados com niveis crescentes de casca de cafe, conduziu-se um experimento em Rondonia-RO; em delineamento inteiramente casualizado com quatro tratamentos, representados pelos niveis de inclusao da casca de cafe de 0, 10, 20 e 30% em substituicao ao capim-elefante ( Pennisetum purpureum Schum.) cv. Cameroon e cinco repeticoes, representados pelos animais. A casca de cafe continha 85,2; 11,3; 0,50 e 0,16 % de MS, PB, Ca e P, respectivamente. A sua inclusao na dieta dos ovinos resultou em maiores ganhos de peso (P?0,01), 9,1; 18,8; 14,5 e 49,1 g/dia/animal, respectivamente, para os niveis de inclusao de 0, 10, 20 e 30%; o consumo medio dos animais alimentados com as racoes contendo a casca foi 14,6% inferior ao dos alimentados exclusivamente com capim-elefante (53,7 x 62,9 g de MS/kg de PV 0,75 ).

Produtividade de forragem e composição química de Stylosanthes capitata cv. Lavradeiro sob níveis de fósforo

The effects of phosphorus levels (0, 40, 80 and 120 kg of P2O5 ha) on green dry matter (GDM), chemical composition and nodulation of Stylosanthes capitata cv. Lavradeiro were evaluated under field conditions in Roraima ́s savannas. Phosphorus fertilization increased significantly (P<.05) GDM yields, nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg) and potassium (K) concentrations and number and dry weight of nodules. Maximum GDM yields and Ca, Mg and K contents were obtained with the application of 89.4; 56.2; 113.1 and 75.6 kg of P2O5 ha, respectively, while the N and P contents and number of nodules were directly proportional to P levels. The P critic level, related to 90% of GDM maximum production, was estimated at 2.43 g kg. The P efficiency utilization was inversely proportional to the P rates applied.

Características morfogênicas e estruturais de Megathyrsus maximus cv. Tanzânia-1 sob intensidades de desfolhação.

O efeito de intensidades de desfolhacao (20, 30, 40 e 50 cm acima do solo) sobre a producao de forragem e caracteristicas morfogenicas e estruturais de Megathyrsus maximus cv. Tanzânia-1 foi avaliado nos cerrados de Roraima.

Caracterização do processamento artesanal da carne de caranguejo-uçá Ucides cordatus e perfil socioeconômico dos quebradores

The Ucides cordatus mangrove crab is one of the most economically important crustaceans in Brazil, being a source of income and work for the fishing communities. Its consumption is one of the Northeastern cuisine attractions, supporting the thematic restaurants greatly appreciated by tourists. Crabs not sold by fishermen or traders are processed locally for meat or pasta crab extraction. This work aimed to diagnose the socioeconomic situation of the workers involved in this activity, as well as the hygienicsanitary conditions of processing, handling and packaging of crabmeat in places called

Produtividade de forragem, composição química e morfogênese de Megathyrsus maximus cv. Mombaça sob períodos de descanso

The effects of rest periods (14, 21, 28, 35, 42 and 49 days) on green dry matter (GDM) yield, chemical composition and morphogenetic and structural characteristics of Megathyrsus maximus cv. Mombaça were evaluated under natural field conditions. GDM yields and regrowth increased consistently with highest rest periods. The leaf appearance and leaf expansion rates are inversely proportional to the rest periods, occurring the inverse for average leaf length, leaf area index and foliar senescence rate. Maximum GDM yields, regrowth yields, number of leaves tiller, average leaf length and leaf area index were obtained with rest periods at 36.4; 39.2; 40.8; 39.6 and 41.3 days. These data suggest that grass grazing at 35 to 42 days of rest period were optimal for obtain maximum yields and regrowth of rich forage.