Ana Paula Ribeiro de Jesus

Quantitative anatomy and in situ ruminal degradation parameters of elephant grass under different defoliation frequencies

Universidade Federal do Maranhão, Centro de Ciências Agrárias e Animais, Departamento de Zootecnia, Chapadinha, Maranhão, Brasil. Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Zootecnia, Fortaleza, Ceará, Brasil. Universidade Federal da Paraíba, Centro de Ciências Agrárias, Departamento de Zootecnia, Areia, Paraíba, Brasil. Universidade Federal do Piauí, Centro de Ciências Agrárias, Departamento de Ciência Animal, Teresina, Piauí, Brasil. *Endereço para correspondência: ricardo_zoo@hotmail.com

Nutrient intake and economic analysis of young bulls reared in silvopastoral systems with babassu palm trees in the Pre-Amazon region

Universidade Federal do Ceara, Centro de ciências Agrárias, Departamento de Zootecnia, Fortaleza, Ceará, brasil. Universidade Federal do Maranhão, Centro de Ciências Agrárias e Animais, Departamento de Zootecnia, Chapadinha, Maranhão, Brasil. Universidade Federal da Paraíba, Centro de Ciências Agrárias, Departamento de Zootecnia, Areia, Paraíba, Brasil. Universidade Estadual do Piauí, Centro de Ciências Agrárias, Departamento de Agronomia, Parnaíba, Piauí, Brasil. Universidade Federal do Piauí, Centro de Ciências Agrárias, Teresina, Piauí, Brasil. Instituto Federal de Educação, Ciência e Tecnologia do Maranhão, São Luís, Maranhão, Brasil. *Endereço para correspondência: ricardo_zoo@hotmail.com

Acúmulo de forragem e estrutura do dossel do capim-Xaraés submetido a intensidades de cortes

The aim of this work was to evaluate the forage accumulation and sward structure of Xaraes grass subjected to five residue heights (10; 20; 30; 40 and 50 cm) with cutting interval based on light interception (LI) by sward during the regrowth (95% of LI). The experiment was conducted in forage production sector of the Agrarian and Environmental Sciences Center of the Federal University of Maranhao, in Chapadinha, in the period from March to November of 2011. A completely randomized design with five repetitions was used. The rest period based on 95% LI strategy varied according to the residue heights and time of year. There was effect of cutting heights for the production of forage, the density of tillers, the number of living tillers, sward height and volumetric density of forage. Only the leaf/stem ratio and the rate of forage accumulation were not influenced by the factors studied, in the rainy season of 2011. In the dry season, the pastures of Xaraes grass were affected in a negative way for all features evaluated, regardless of heights of residue. In General, more drastic cuts intensities (10 cm) promote higher forage production, greater density of tillers, larger number of dead tillers and higher density, however, results in less number of cuts and greater interval between cuts. The reverse occurs with more lenient cuts intensities (40 and 50 cm).

PRODUÇÃO DE FORRAGEM E CARACTERÍSTICAS MORFOFISIOLÓGICAS DO CAPIM-MULATO CULTIVADO EM LATOSSOLO DO CERRADO EM FUNÇÃO DE DOSES DE NITROGÊNIO E POTÁSSIO

The maintenance and productivity of forage plants may have their efficiency maximized by increased use of fertilizers. In this sense, this work aimed to determine the influence of combinations of these nutrients in the productive (forage production, tillering and leaf area estimates) and morphophysiological (RSE, NLL, NLT, LBL, LAR, RELB, RLS and LL) characteristics during three stages of growth of Brachiaria hybrida cv. Mulato. The experiment was carried out in a greenhouse at CCAA/UFMA. A completely randomized design with factorial arrangement 4 x 2 (four doses of N and two doses of K) were used, comprising eight treatments and five replicates, totaling 40 experimental units. The treatments consisted of increasing doses of nitrogen: 0, 75, 150 and 225 kg/ha and two levels of potassium fertilization: 20 and 60 kg/ha of K2O. For the production characteristics, in the first cut, there was effect for the production of fodder, in which the behavior of the equation was similar to the doses of 20 and 60 kg/ha of K2O, but the magnitude of response was higher for the dose of 60 kg/ha of K2O, which did not occur to tillering of the grass that regardless of the dose of K, in which the higher the dose of N, greater was the tillering. For the estimation of leaf area there was no statistical difference of any factor studied. In the second and third cuts, the total forage yield, tillering and leaf area were influenced only by rates of N. In all cases, the equations fitted the linear regression model. Like the production characteristics, the morphophysiological characteristics have different responses over the cuts, which show that the management of Mulato grass should not be generalized, because it depends on the stage of growth/development of plants. The N influenced positively the productive and morphophysiological characteristics of Mulato grass being the influence more evident through the supply of 60 kg/ha of K2O.

PRODUÇÃO E MORFOFISIOLOGIA DO CAPIM BRACHIARIA BRIZANTHA CV. XARAÉS SOB DOSES DE NITROGÊNIO E FÓSFORO

The objective of this study was to evaluate the production and morphological and physiological characteristics, yield and crude protein (CP) concentration of Brachiaria brizantha cv. Xaraes submitted to nitrogen and phosphorus. The experiment was conducted in a greenhouse. Four levels of nitrogen (0, 75,150 and 225 mg/dm3) and three levels of phosphorus (0, 140 and 280 mg/dm³) were used. The N increased the dry weight of shoots and roots and the density tiller (DT) in all plant growth, while phosphorus levels increased the dry weight in the first growth and increased DT in the first and third harvests. The interaction of N and P occurred only in the second cut in production of shoot dry mass. The combined rates of N and P influenced the content of CP in the various categories of leaves and stem plus sheats. None of the nutrients employeed or their interaction was significant on the photosynthetic rate, conductance, intercellular CO2 concentration and transpiration and the leaf/stem ratio.