Emerson Alexandrino

Índices morfogênicos e de crescimento durante o estabelecimento e a rebrotação do capim-Mombaça (Panicum maximum Jacq.)

A trial was carried out in green-house to estimate morphogenic traits and growth indices of Mombacagrass development. Three growths were considered: the seminal, establishment growth (G1) and the regrowths following a clipping taken on the 16th (G2) and 37th (G3) days of the seminal growth. The variables assessed were the growth indices: relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), and the rates of leaf appearance, elongation, expansion and senescence. Accordingly, harvests were taken at the ages of: 13, 20, 27, 42, 55, 69 and 83 day of the seminal growth (G1); 0, 3, 6, 10, 17, 24, 38, 52 and 66 day of the 2nd regrowth (G2) and 0, 1, 3, 7, 21, 35, 49, 63 and 77 day of the 3rd growth (G3). There were three replications (pots) per treatment in a completely randomized design. Figures for NAR, LAR and RGR were high during early seminal growth but declined assynthotically as plant aged. Initial values for these indices were higher in the seminal growth as compared to the 2 regrowths. Cutting taken on the 37th day of the seminal growth hindered the initial growth of the plants regarding leaf appearance and elongation rates, LAR, NAR and RGR. The latter two indices which had negative values during early regrowth, were recovered by the 16th regrowth day.

Cultivares de milho e de gramíneas forrageiras sob monocultivo e consorciação

The purpose of this study was to evaluate the performance of maize and forage grass ( Brachiaria brizantha and Panicum maximum ) cultivars under monocropping and intercropping systems. The experiment was carried out in randomized complete blocks, in a 3x4 + 7 factorial design, with four replications. The first factor consisted of three maize cultivars (AL Bandeirantes, an open pollination variety; AG 2040, a double cross; and Pioneer 30F87, a triple cross) and the second one included four forage cultivars (Marandu and Xaraes, from B. brizantha , and Tanzânia and Mombaca, from P. maximum ). The seven additional treatments consisted of the respective tested cultivars monocroppings. Maize and forage grasses were sown simultaneously, the first in rows, spaced 1.0 m apart, and the second by throwing. Hybrid Pioneer 30F87 maize yields were the highest ones, for both monocropping and intercropping systems, and maize affected dry weight gain of forages, when compared to the monocropping system. For intercropping, P. maximum forage cultivars were the most productive ones, while, for monocropping, the Mombaca cultivar presented the highest dry matter production level. KEY-WORDS: Zea mays ; Brachiaria brizantha ; Panicum maximum ; agriculture and livestock integration; pasture.

Desempenho em confinamento de bovinos de corte, castrados ou não, alimentados com teores crescentes de farelo do mesocarpo de babaçu

The objective was to evaluate four levels of inclusion of babassu mesocarp meal (Orbygnya spp.) in the concentrate on cattle feedlot performance. Twenty four animals (12 steers and 12 bulls) were used with age and body weight of 33 months and 332.1±24kg, respectively. Diets were isonitrogenous, composed of 44% of Mombasa grass silage and 56% of concentrate in dry matter. Corn grain of the concentrate fraction was replaced by babassu mesocarp meal at 0, 20, 40 and 60% in dry matter. The experimental design was randomized complete block, with factorial arrangement of treatments 4x2 (four levels of babassu mesocarp meal inclusion and two sexual conditions). Dry matter intake in kg day1 and percentage of body weight was not altered by the inclusion level of bran babassu mesocarp, with average values of 9.37kg day-1 and 2.54% respectively. Inclusion levels of babassu mesocarp meal did not affect daily weight gain and feed conversion the animals, with average values of 1.157kg day-1 and 8.39kg of dry matter kg-1 weight gain. Bulls had higher daily weight gain (1.259kg day-1) than steers (1.066kg day-1), reflecting a better feed conversion (7.702 and 9.094kg dry matter kg-1 weight gain, respectively). Babassu mesocarp meal, such as alternative energy source, can be fed to feedlot to the 60% level of inclusion in the concentrate, replacing corn grain.

Feeding behaviors of feedlot bulls fed concentrate levels and babassu mesocarp meal

The objective of the present study was to evaluate the feeding behavior of feedlot Nellore bulls fed two levels of concentrate (650 and 710 g/kg dry matter) with or without the inclusion of 350 g babassu mesocarp meal/kg dry matter in the concentrate. Twenty-eight animals at 18 months of initial age and 356.66±19.25 kg initial body weight were used. A completely randomized design was used with treatments in a 2 × 2 factorial arrangement. Increase in concentrate level from 650 to 710 g/kg dry matter did not change the feeding time, of 194.41 and 189.64 minutes/day, respectively. The inclusion of 350 g babassu mesocarp meal/kg dry matter in the concentrate increased the feeding time from 173.92 to 210.12 minutes/day, ensuring similar energy intake in relation to the diets without this byproduct. Rumination time was not changed by increasing the concentrate level in diets with 350 g babassu mesocarp meal/kg dry matter in the concentrate, with average values of 420.48 and 398.09 minutes/day for the levels of 650 and 710 g concentrate/kg dry matter, respectively. However, in diets without babassu mesocarp meal, the rumination time was reduced by the concentrate level, with average values of 452.14 and 409.76 minutes/day for 650 and 710 g of concentrate/kg dry matter, respectively. Time spent on other activities increased from 810.23 to 860.00 minutes/day with increase in the concentrate level, which was not changed in the diets containing babassu mesocarp meal. The inclusion of babassu mesocarp meal in the diet altered the feeding behavior of feedlot cattle, due to the need to increase the feeding time to maintain the energy intake.

Características estruturais e agronômicas da Brachiaria brizantha cv. Xaraés submetida a doses de nitrogênio

The objective of this experiment was to evaluate the structural characteristics and agronomic traits of Brachiaria brizantha cv. Xaraes under different nitrogen levels (0, 125, 250, 375 and 500 kg.ha-1 of N) grown in Campus Rondonopolis, Mato Grosso, in the period 10/12/2006 to 08/23/2007. The treatments were arranged in a randomized design with four repetitions. The results were submitted to statistical analysis by grouping the data into two periods: rain and throughout the year. The N influenced the number of leaves appeared at the time rainy, and the number of green leaves. The number of leaves was influenced by N rates during the rain and throughout the year. There was an increase of 27% in the average length of the leaf blade to the dose of 343.9 kg ha-1 N for the rainy season. The density of tillers was influenced by N rates for both evaluation periods. Since the height of the plants was influenced by N rates for the two seasons evaluated. The increased availability of dry per hectare was 87.5% for the highest N in the water (333.3 kg ha-1 N) compared with the control treatment. Nitrogen fertilization positively influences all characteristics related to growth and production mass, especially during the rainy season, when the fertilization must be divided into four or five doses, with no need for fertilization in the dry season.

Características agronômicas e estruturais de híbridos de sorgo em função de diferentes densidades de plantio

The objective of the experiment was to evaluate the agronomic characteristics of two sorghum hybrids for silage production, AG-2005 (double purpose) and VOLUMAX (forage) cultivated with different row spacing 1; 0.75 and 0.50 m, on Orthic Quartzarenic Neosol, resulting in 140,000; 186,666 e 280,000 plants per ha, respectively. A randomized block design with four replicates was used and the treatments consisted on a factorial arrangement 2 x 3. Were determined the total dry matter production (PMST), of leaves (PMLF), of stems (PMSC), and panicles (PMSP) per ha, and their proportion in the whole plant. Significant interaction occurred between sorghum hybrid and row spacing for PMST, PMSLF and PMSP. VOLUMAX showed similar production for the three row spacing. AG-2005 showed higher PMST (9,474.59 vs. 6,842.91 kg ha-1) and PMSP (6,355.77 vs. 3,032.40 kg ha-1) than VOLUMAX in 0.50 m row spacing. AG-2005 was superior to VOLUMAX for the percentage of panicles in 1 m (57.06 vs. 40.22%) and 0.50 m spacing (66.99 vs. 43.55%), and VOLUMAX was superior for stems percentages in the 1 and 0.50 m spacing. It is recommended the use of hybrid AG-2005 under spacing of 0.50 m for silage production, due to its higher dry matter production per area, higher percentage of panicle and lower percentage of stem in the composition of the plant compared to the hybrid VOLUMAX.

Características agronômicas, estruturais e bromatológicas do capim Piatã em lotação intermitente com período de descanso variável em função da altura do pasto

Objective was to evaluate the influence of different grazing height on agronomic, structural and qualitative characteristics of Brachiaria brizantha cv. Piata managed under rotational stocking. We evaluated three sward heights (30, 45 and 60 cm) over two growing seasons (Middle and Final Season). We adopted the randomized complete block design with split plot, where the plots were allocated heights and subplots the growing seasons. Height values met the experimental protocol, showing averages of 35.2; 43.5 and 59.4, respectively 30, 45 and 60 cm. The rest period was variable during the heights and providing different grazing cycles, with an average DP of 34, 39 and 54 days, respectively, to the heights studied . The highest yield obtained by MST cycle was at the height of 60 cm, with an average of 4612.51 kg ha-1 and 3566 kg ha-1 to 30 cm height. However the heights of 30 and 45 cm three cycles of grazing and only two to the height of 60 cm were obtained, totaling about it, 12.4, 10.7 and 9.2 t DM ha-1 in the period. In leaf/stem ratio, no differences in heights studied. The number of tillers did not change with different heights, the superiority in the number of tillers was observed in the middle of the growing season. The increase in sward height provided no change in CP content and digestibility and increased levels of ADF, NDF was changed only at the height of 60 cm.

Características das carcaças e carne de tourinhos Nelore alimentados com níveis de concentrado e farelo do mesocarpo de babaçu

Carcass characteristics and meat of young bulls fed different levels of concentrate and babassu mesocarp bran in the diet were evaluated. A total of 28 Nellore young bulls, initial age of 21 months and 356.66±19.25kg of initial body weight were randomized in diets containing two levels of concentrate (65% and 71) associated or not to the inclusion of 35% of babassu mesocarp bran in the concentrate. The elevation of the concentrate fraction of the diet from 65 to 71%, and the inclusion of 35% of babassu mesocarp bran in the concentrate did not alter the amount of muscle, fat and bone of the carcass, with average values of 63.91, 19.46 and 16.63% of cold carcass weight, respectively. The yields of retail cuts from the pistol cut were not altered by the concentrate level of the diet or by the inclusion of 35% babassu mesocarp bran in the concentrate. The shear force of muscle fibers and the losses of liquid during thawing and cooking were not altered by the factors studied, with average values of 6.57kgf/cm3, 16.06% and 22.20%, respectively. Marbling increased (5.78 to 9.79 points) to advance the level of concentrate in the diet, but was not altered by the inclusion of babassu mesocarp bran. Babassu mesocarp bran has nutritional characteristics that allow partial replacement of corn in diets with high concentrate, not changing physical carcass composition and meat quality of confined young Nellore bulls.

Spatial variation and area definition of nutrient extraction by Marandu grass biomass

The present study aimed to quantify, describe and identify areas of nutrient extraction by Brachiaria brizantha cv. Marandu biomass in integrated forest-pasture systems from a Cerrado-Amazon transition region with Typic Quartzipsamment soil by using geostatistical techniques, principal components analysis and non-hierarchical fuzzy k-means clustering. The evaluations were conducted in two integrated forest-pasture systems from an association with Brachiaria brizantha cv. Marandu and native 1 Prof., Instituto Federal de Educação, Ciência e Tecnologia do Tocantins, Gurupi, TO, Brasil. E-mail: sabino.pereira@ifto.edu.br 2 Profs., Fundação Universidade Federal do Tocantins, Araguaína, TO, Brasil. E-mail: clementino@mail.uft.edu.br; e_alexandrino@ yahoo.com.br; araguaia2007@gmail.com; jgsanttos@gmail.com; jecs@uft.edu.br 3 Prof., Instituto Federal de Educação, Ciência e Tecnologia do Tocantins, Araguatins, TO, Brasil. E-mail: laerton.leite@ifto.edu.br * Author for correspondence

Morphogenetic and structural characteristics of Urochloa spp. under conventional management and intercropped with cereals

Integrated crop-livestock systems are an alternative to the traditional model of land use, which seeks to promote the technical, ecological and socio-economic viability of the area used. The aim was to evaluate the morphogenetic and structural responses of two established cultivars of Urochloa brizantha at two times of the year, using conventional and integrated crop-livestock systems. The experimental design was of randomised blocks in a 2 x 3 x 2 triple factorial scheme consisting of two forage plants (Marandu and Piata), three management systems (conventional and intercropped with corn and sorghum) and two seasons (summer and autumn), with four replications. Morphogenetic and structural characteristics were evaluated. The integration of tropical forage grasses with grain crops resulted in no negative impacts on the morphostructural characteristics of the cultivars of Urochloa brizantha; the seasons of the year promoting major changes, such as a reduction of 33.8% in the lifespan of leaves in the summer. However, in that season there was an increase of 39.3 and 30.9% in the rate of leaf emergence and elongation respectively. It can be seen that an integrated agricultural system is efficient in creating pasture, and that Marandu grass and Piata are alternatives to this type of system.