Effect of ammoniation and moisture-content on the quality of signal grass (Brachiaria-decumbens stapf) hay

The experiment was carried out to evaluate the effects of two moisture levels (18-20% and 13-15%) and three anhydrous ammonia levels (0.0; 1.5; 3.0% of NH3) on the quality of Brachiaria decumbens Stapf hay. The hay was bailed in April and weighed and treated under plastic cover during 30 days. The hay presented a similar chemical composition when bailed with high or low moisture. The percentages of NDF (80.59; 77.61; 76.10%); hemicellulose (32.56; 29.48; 28.76%) and lignin (9.53; 8.21; 7.54% decreased and the percentages of crude protein (4.04; 11.35; 13.22%) and IVDMD (36.78; 49.72; 54.33%) increased as the NH3 level increased. The fractions ADF, cellulose, and ADIN did not change due to the ammoniation. The incidence of fungi decreased with application of NH3 being the better results obtained with the 1.5% treatments.

Impact of overseeding cool-season annual forages on spring regrowth of tifton 85 bermudagrass

Field observations have shown stand reduction and slow spring regrowth of Tifton. 85 bermudagrass (Cynodon spp.) pastures overseeded with temperate forages for grazing during the cool season. This experiment compared the effect of cool-season management programs, including overseeding and use of different grazing treatments, on productivity of Tifton 85 the following warm season. There were seven treatments: four were bermudagrass overseeded with a cool-season annual forage mixture (two grasses and two legumes) and grazed differentially, and three were bermudagrass controls With differences in amount of residual stubble remaining at beginning of autumn. There was only a slight delay in initiation of Tifton 85 spring regrowth relative to the unseeded controls and no apparent stand loss resulting from overseeding cool-season forages. Late spring and summer Tifton 85 production generally was greater on seeded than non-seeded areas, possibly resulting from the nitrogen (N) release from decaying cool-season legumes. Grazing management of winter species in seeded plots and stubble height of bermudagrass in control plots had no effect on bermudagrass performance. Nutritive value responses generally favored overseeded plots. These data, though from one year, show no negative effect on Tifton 85 bermudagrass performance from overseeding and grazing cool-season annual forages during winter.

Carbon Stocks and Isotopic Composition of the Organic Matter in Soils Covered by Native Vegetation and Pasture in Sorocaba, SP, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Atributos físicos de latossolo vermelho sob pousio ou cultivado com forrageiras tropicais sob pastejo

The objective was to study the physical attributes of an Oxisol under fallow or planted with tropical grasses under grazing. The experiment was conducted under the experimental design of randomized blocks in split-plot 2 x 5, being five types of use of soil (Brachiaria ruziziensis, Panicum maximum cv. Aries, Brachiaria brizantha cv. MG5, Panicum maximum cv. Mombaca and fallow) and two evaluation periods (after the first and after the second grazing), with four replications. We evaluated the characteristics of soil bulk density, total porosity, microporosity and macroporosity, after the first and second grazing, and soil resistance to penetration after the second grazing. In layer of 0.00 to 0.10 m, the macroporosity was affected by the interaction between types of use and evaluation periods, while the microporosity and total porosity were reduced and the density was increased from first to second evaluation time. In the subsurface layer (0.10-0.20 m), there were significant effect only of evaluation time, on the macroporosity, total porosity and density. The porosity were reduced, while the density increased from first to second evaluation time. No significant effects of types of use of soil on penetration resistance in all layers studied. The maintenance of an Oxisol under fallow or cultivation with tropical grasses subjected to grazing cattle causes a reduction in total porosity and increased density of surface soil layers (0 to 0.10 m) and subsurface (0.10 - 0.20 m), without promoting changes on resistance to penetration mechanics.

An Innovative Crop-Forage Intercrop System: Early Cycle Soybean Cultivars and Palisadegrass

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relação entre o fluxo luminoso interceptado em diferentes épocas no índice de área foliar de diferentes forrageiras

The objective was to evaluate the leaf area index of six different grasses. The experiment was installed at the Instituto Federal de Tecnologia e Educacao of Uberaba, using a randomized block design with split plots in time. The plots were sown: Brachiaria decumbens cv. Basilisk, Brachiaria brizantha cv. Marandu, Panicum maximum cv. Mombasa, Panicum maximum cv. Tanzania, Brachiaria brizantha cv. Xaraes, Cynodon dactylon hb. Tifton and the plots, ten seasons of evaluation in 10 x 6 factorial arrangement with four replications. Rates of leaf area of each forage at different times of year were evaluated. Compared to other forage species, Panicum maximum had a higher leaf area index when subjected to periodic fertilization and irrigation. Only in the late fall Brachiaria Xaraes IAF had increased, but did not differ significantly from the others.

Avaliação agronômica de sete acessos de Hemarthria altissima [poir.]stapf et C.E.Hubb.em Pindamonhangaba, SP

The experiment was carried out to evaluate seven accessions of limpograss Hermathria altissima (PI 364888, NO 158, PI 364863, IPEACO 336, UF 553, UF 347238, and IPEACO 337) as compared to coast-cross grass (Cynodon dactylon), to determine which grasses were best adapted ecologically to conditions at Pindamonhangaba. The experimental design was a randomized block with four replications. Five annual harvests were taken during the three-year experimental period, two in the dry season and three in the rainy season. The higher annual DM yields (kgDM/ ha) were obtained with accessions UF 553 (19996), NO 158 (18745), and PI 347238 (18267). Accessions UF 553 and IPEACO 336 had the most uniform production throughout the year with 37.4 and 33.2% during the dry season, respectively. Coast-cross had the highest percentage of crude protein (10.30%), while limpograss values varied around 7%. It was concluded that accession UF553 was the most promising grass for the Pindamonhangaba region.

Root growth and nutrient accumulation in cover crops as affected by soil compaction

Crop rotation using cover crops with vigorous root systems may be a tool to manage soils with some degree of compaction. Root and shoot growth as well as nutrient accumulation by summer species suitable for crop rotation in tropical areas were studied at different subsoil compaction levels. Crotalaria juncea (Indian hemp), Crotalaria spectabilis (showy crotalaria), Helianthus annuus (sunflower), Pennisetum americanum (pearl millet) and Sorghum bicolor (guinea sorghum) were grown for 40 days in pots 33.5 cm high with 10 cm internal diameter. Soil in the pots had uniform bulkdensity of 1.25 Mg m-3 for the top and bottom 15 cm sections. Bulk densities of 1.31, 1.43, 1.58 and 1.70 Mg m-3 Were established in the 3.5 cm middle section. H. annuus and P. americanum had the highest early macronutrient accumulation. The grasses S. bicolor and P. americanum yielded twice as much shoot dry matter as the other species. Root growth generally decreased with increasing soil bulk density with C. spectabilis less affected than other species. Although the grasses were more sensitive to high soil penetration resistance, they showed higher root length densities at all compaction levels. P. americanum had the highest potential to be used as cover crop due to its high root density at high soil penetration resistances, vegetative vigour and ability to accumulate macronutrients. © 2002 Elsevier Science B.V. All rights reserved.

Metano entérico de bovinos leiteiros em condições tropicais brasileiras

The objective of this work was to quantify methane (CH4) emission using the sulfur hexafluoride (SF6) tracer technique, by dairy cattle on pasture in Brazilian tropical field conditions. Measurements were performed in the rainy season, with Holstein and Holstein x Zebu crossbred, from lactating and dry cows and heifers grazing fertilized Tobiatã grass, and heifers grazing unfertilized Brachiaria grass. Methane and SF6 concentrations were determined by gas chromatograph. Methane emissions by lactating cows varied from 13.8 to 16.8 g/hour, by dry cows from 11.6 to 12.3 g/hour, by heifers grazing fertilized grass was 9.5 g/hour and by heifers grazing unfertilized grass varied from 7.6 to 8.3 g/hour or 66 to 72 kg/head/year. Methane emission per digestive dry matter intake (DMDI) varied from 42 to 69 g/kg DMDI for lactating cows, 46 to 56 g/kg for dry cows, 45 to 58 g/kg for heifers grazing fertilized grass and 58 to 62 g/kg for heifers in unfertilized grass pasture. The CH4 emission measured on dairy cattle feeding tropical grasses was higher than that observed for temperate climate conditions.

Uso da fitossociologia na avaliação da efetividade da restauração florestal em uma várzea degradada do rio Mogi Cuaçu, SP

This study objective was to evaluate the effective revegetation in a Mogi Guaçu River degraded floodplain area, located at Luiz Antonio municipality (21° 31' S e 47° 55' W), São Paulo State, Brazil. Two native riparian forest remnants (RIP1 and RIP2) and three 10-year-old reforested areas, planted of native species (R1, R2 and R3), were analyzed by using phytosociological describers of the arboreal stratum (trees with DBH ≥ 5 cm) as indicators. The arboreal stratum inventory was accomplished by 180 plots (10 × 10 m each), 60 representing every native forest and 20 for every reforested area. A total of 60 arboreal species was recorded, only six species (Cecropia hololeuca, Crotón urucurana, Genipa americana, Inga striata, Nectandra megapotamica e Peltophorum dubium) occurring in all the five studied areas. Seventeen species were common to both native forests, and nine species were recorded in all the reforested areas. Sebastlania commersonlana and Guarea macrophyllawere recorded in the native forests (RlP1 and RIP2), and Cecropia hololeuca, Croton urucurana and Inga striata occurring in all the reforested areas, were the species that best characterize the physiognomy of local diversity and were the most important among the studied species. The results showed that the rehabilitation of the areas made by the reforestation created conditions to implant forests with similar structures of the adjacent natural remainders. The reforestation with native species performed in the degraded floodplain of Mogi Guaçu River, initially with the predomination of invasive grasses, has been effective at the first stage of the ecological restoration process. The reforestation is making possible the natural regeneration of species from the adjacent remnants, what indicates that the similarity between planted forests and the native ones are rising through the time. The phytosociology, accomplished ten years after the planting date, is adequate to evaluate the effectiveness of the reforestation during the restoration process of degradated areas in the Mogi Guaçu floodplain.

Isolation and growth of the symbiotic fungus of Atta capiguara (Hymenoptera: Formicidae)

This work's objectives were to isolate and evaluate the growth of the symbiotic fungus of Atta capiguara Gonçalves on artificial medium, under different pH and temperature conditions. Isolation was accomplished using the following media: Sabouraud, oat-agar, PDA, and PDA with the addition of extracts from the grasses Paspalum sp. Flügge and Hyparrhenia rufa (Nees) Stapf.. The medium used in the growth study was PDA with the addition of a Paspalum sp. (0.22%, w/v) extract at initial pH values of 4.5, 6.0, and 7.5. Mycelium disks were transferred to plates containing the culture medium. The plates were maintained at temperatures of 20, 23, and 26 ± 1°C. Mycelial radial growth evaluations were performed at 7, 14, 21, 28, and 35 days of incubation. Fungus isolation was obtained in all media studied. The highest radial means were obtained at initial pH values of 6.0 and 7.5 and temperatures of 23 and 26± 1°C. Greater plot losses occurred at the initial pH condition of 7.5. In general, A. capiguara fungi can be grown in the medium studied, at an initial pH of 6.0 and temperatures of 23 or 26± 1°C. Radial growth evaluations at 14 and 28 days of incubation can be recommended for substrate studies involving the symbiotic fungus.

Potencialidades da utilização de taninos na conservação de forragens e nutrição de ruminantes-revisão

This review present a discussion abouth the tannins. The tannins are compounds that have the ability to bind other macromolecules, reducing their availability to animal metabolism. This characteristic can be benefic or deleterious, depending on the tannin concentration degree in the plant and its structure. Positive effects are mainly related with a better use of the dietary protein and an increased efficiency of microbial protein synthesis in the rumen. The use of tannins to reduce ruminal methane emission has been subject of current researches, firmly indicating a decrease of ruminal methanogenesis. However, many of these studies, carried out to evaluate the effects of tannins on forage fermentation and animal metabolism, are based on legume plants, so their results can not be surpassed to studies concerning tanniniferous grasses. By improving the characterization of the profile and reactivity of tannins in tanniniferous forages, such as some sorghum hybrids, as well as conducting experiments to demonstrate the effects of tannins on animal metabolism and performance, the real potential of forages with tannin will be enlightened.

Distribuição, tamanho populacional, hábitat e conservação do bicudinho-do-brejo Stymphalornis acutirostris Bornschein, Reinert e Teixeira, 1995 (Thamnophilidae)

The Marsh Antwren (Stymphalornis acutirostris) is restricted to the lowlands between Antonina Bay, in the coastal plain of the state of Paraná, and Itapocu river, in the northern coastal plain of the state of Santa Catarina (from 0 to c. 5 m a.s.l.). It doesn't occur continuously in this region, being found in eight populations that span over an total area of about 6,060 ha (= area of occupancy; 4,856.67 in Paraná and c. 1,200 in Santa Catarina). Nine habitat types used by the Marsh Antwren were defined, based on vegetation physiognomy, localization, dominancy of botanical species, dominant life-form and history of the region. Five of these are herbaceous (marshes), while four have an upper arboreal stratum and an herbaceous lower stratum with marsh plants. According to the classification criteria of the Brazilian vegetation proposed by the Radambrasil Project, they were classified as Pioneering Formation of Fluvial Influence, Pioneering Formation of Fluvial-marine Influence, and/or Pioneering Formation of Lacustrine Influence. They occur as patches or narrow strips ranging from 0.001 to 203.0 ha in the state of Paraná. They are found mainly in the interior of bays, in the lower courses of rivers that drain into bays, in alluvial plains, and between sand dunes in the coastal plain. Characteristic herbaceous species are cattail (Typha domingensis), bulrush (Scirpus californicus), Crinum salsum, Panicum sp. cf. P. mertensii, saw grass (Cladium mariscus) and Fuirena spp. Hibiscus pernambucensis is the characteristic bush species, and Calophyllum brasiliense, Tabebuia cassinoides, Annona glabra and Laguncularia racemosa are the characteristic arboreal species. The Marsh Antwren lives in herbaceous vegetation, but also uses bushes and branches of small tress. It has low flight capacity and a single flight of more than 25 m was never recorded. Territories of 0.25 ha were estimated in one kind of habitat (tidal marsh) (= 8 individuals per hectare) and of 3.2 ha in another one (saw grass marsh) (= 0.62 individual per hectare). The global population estimate is of about 17,700 mature individuals (13,700 in Paraná and 4,000 in Santa Catarina). The species is really under threat of extinction, mainly because of it's restricted geographical distribution and habitat loss by human activities and biological contamination caused by invasion of exotic grasses (Urochloa arrecta and Brachiaria mutica).

Desempenho ponderal de novilhas mestiças Holandês x Zebu submetidas a duas estratégias de suplementação mineral

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparações entre equações de predição de consumo de capim-elefante cortado para vacas lactantes

This work aimed to compare intake prediction equations with values obtained by direct methods using chopped elephant-grass offered to crossbreed lactating cows with rumen canulas. The experimental design was a 3 x 3 Latin square (three animals and three cutting ages: 30, 45 and 60 days). The equations used for intake prediction (y) were: (1) y= -1.19 + 0.035(a+b) + 28.5c; (2) y= [%NDF on DM]*[NDF intake]/[(1- a - b)/KP+b/(c+kp)]/24; (3) y= -0.822 + 0.0748(a+b) + 40.7c and (4) equation 2 with values of intake measured directly. The predictions of NDF intake by equations were not different among treatments, instead of the difference among values measured directly: the 30 day-old had lower intake (5.29 kg/day) in relation to 45 (6.57 kg/day) and 60 (7.31 kg/day) day-old grasses. In general, equations overestimated the DM intake in relation to direct measuring (9.0 kg/cow/day), with exception of equation 3 which underestimated the intake (7.7 kg/day). The means of DM intake found by equations 1 and 2 (13.7 and 13.4 kg/cow/day, respectively) were similar between themselves and superior in relation to those found by equation 4 (9.7 kg/cow/day). The intakes measured directly were similar to those found in equation 4 and higher than those found by equation 3. The mean of rumen fill of 7.5 kg was superior to those of 5.2 kg estimated by equation. The prediction equations based on in situ degradability parameters do not supply estimates of DM intake, NDF intake and rumen fill in agreement with values obtained by direct methods.