Aditivos na ensilagem do capim-elefante. I. Composição bromatológica das forragens e das respectivas silagens

The effect of the addition of ground ear corn with husks, wheat bran and saccharin, on the rate of 0, 8, 16 and 24% (dry weight of additive/wet weight of cut green grass), upon the chemical composition of both fodder and silage of Pennisetum purpureum Schum. cv. Guaçu was evaluated. A split-plot randomized block design was used. The plots were the additives and their levels and the sub-plots the material types (forage + additives and their silages). The grass was fertilized with 20 t/ha of green manure and 80, 160 and 160 kg/ha of P2O5, N and K2O, respectively. The material (chopped grass mixed with the levels of the additives) was ensiled in experimental silos (200 L plastic vessels). The dry matter percentages increased linearly as additive levels increased, being greater the effect of ground ear corn with husks. Wheat bran addition and saccharin increased the crude protein and soluble carbohydrates percentages while the ground ear corn with husks addition decreased them. Losses of dry matter soluble compounds (CP, ash and NFE) and a relative rise in the less soluble compounds (CF and organic matter) were observed.

Aditivos na ensilagem do capim-elefante. II. Qualidade das silagens amostradas por dois métodos

Silages of Pennisetum purpureum Schum. cv. Guaçu prepared with 0, 8, 16 and 24% of ground ear com with husks, wheat bran and saccharin, dry weight of additive/wet weight of green chop basis. The experimental design was a randomized blocks one in split-plot; the plots were the additives and levels, and the sub-plots the sampling methods. The material was ensiled using plastic vessels in middle of which holed pvc pipes (3 inches diameter) were put. These pipes (one per vessel) had the same length as the height of the vessels, and were filled at the same time and compacted the same way as the vessels. The first method of sampling used the material ensiled inside the pvc pipe, which was lifted out from the vessel at the moment of the silo opening. The other sampling method, normaly used in digestibility trials, consisted of samples composed by daily sub-samples collected in the vessels. The pvc sampling method was more efficient because it sampled a profile of the whole silage. All of the silages showed high percentages of lactic acid and low percentages or even absence of butyric acid, though in all silages high ammoniacal-N percentages were detected.

Aditivos na ensilagem do capim-elefante. III. Valor nutritivo e consumo voluntário e digestibilidade aparente em ovinos

The intake, the apparent digestibility and the nutritive value of elephant grass (Pennisetum purpureum Schum.) silages prepared with the addition of 0, 8, 16 and 24% of ground ear corn with husks, wheat bran and saccharin, dry weight of additive/wet weight of green chop upon the silage were evaluated. A randomized block design with three replications, in a factorial arrangement (3 additives x 4 levels) was used. As experimental silos, 200-liter plastic vessels were used. Sheep weighing approximately 50 kg, kept in individual cages, receiving water and mineral mixture ad libitum, were used to measure the intake and apparent digestibility of silages. There was a ten-day period of adaptation to the experiment conditions. The voluntary intake of the silages was determined by the mean of the intake observed in the last three days of a ten-day period. The fecal collection period lasted for seven days. In this period the animals were fed 80% of the observed intake obtained in the previous phase. The dry matter intake increased as the levels of the additives in the silages were increased. The digestibility of the wall cell components decreased as the rates of the additives in the ensilage process increased. The silages prepared with wheat bran or ground ear corn with husks showed higher nutritive value than the ones with saccharin.

Aditivos na ensilagem do capim-elefante. IV. Fermentação ruminal em ovinos

The ruminai fermentation patterns of sheep fed elephant grass (Pennisetum purpureum Schum.) silage enriched with ground ear corn with husks, wheat bran and saccharin in the levels 0, 8, 16 and 24% dry weight of additive/wet weight of green chop was evaluated. A split-plot randomized block design was used. The plots were the additives and their levels and the sub-plots the time of rumen fluid collection (0, 1, 3, 6, 9, 12 and 24 h after feeding). During the collection period, the sheep were fed 80% of the observed voluntary feed intake of the previous phase. For all additive types and levels used in preparing the silages, high levels of total volatile fat acids were observed, with predominance of the acetic acid. The silages having ground ear corn with husks as additive showed, in the ruminai fluid, ammonia production levels below the recommended for maximum microbial protein synthesis. However, silages with saccharin or wheat bran presented a good ammoniacal-N availability. In the ruminal fluid of the sheep fed ground ear corn with husks or wheat bran the molar proportion of butyric acid was increased and that of acetic acid and pH were decreased, as the levels of the additives in the silage increased.

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.

Composição e digestibilidade in vitro de genótipos de capim-elefante, aos 56 dias de rebrota

Twelve elephant grass genotypes were evaluated in a randomized blocks design with three repetitions. The experimental parcel was of 4 lines with 3m of length, spaced of 1 m and fertilized with 100 kg of P2O5, 100 kg of N, 60 kg of K2O and 25 kg of micronutrients/ha. Significant differences were observed among the genotypes for neutral detergent fiber (FND), acid detergent fiber (FAD) and lignin. The genotypes CNPGL 92-70-02, CNPGL 91-25-01 and CNPGL 93-32-02 showed low values for FND, FAD and lignin, simultaneously, outstanding between the others. There were no significant differences in the levels of dry matter and crude protein contents and in in vitro dry matter digestibility between the genotypes.

Diferentes níveis de torta de nabo forrageiro (Raphanus sativus) como aditivo na silagem de capim elefante

The aim of the study was to evaluate the effects of the inclusion of different levels of turnip cake (TNF) on the chemical composition, digestibility and quality of elephant grass silage. Due to the quality of the oil extracted from the seeds, the turnip is being considered as an important option for the biodiesel industry in Brazil. The turnip cake is obtained from the mechanical pressing of the seeds to produce oil, and it differs from the meal by the content of fat. In the meal the fat is less than 1%, due to the use of solvents for the oil extraction. Experimental silos were used in a completely randomized design, in factorial arrangement 2 x 3 (two types of material and four levels of inclusion). The materials were represented for original material (fresh) and ensiled material, with four levels of inclusion of TNF (0, 3, 6, and 9%). Dry matter (DM), ether extract (EE), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), nitrogen indigestible neutral detergent (NIDN), nitrogen indigestible acid detergent (NIDA), ash (MM), lignin (LIG), buffer power (PT), calcium (Ca), phosphorus (P) and in vitro dry matter digestibility (IVDDM) were determined in all materials. In silage, additionally, were determined pH and amoniacal nitrogen (NH3-N). There were effects of inclusion of TNF and the type of material on the DM, CP, ADF, NIDA, P, and MM contents and on IVDDM. The interaction of the two factors was observed to the contents of CP, NDF, ADF, NIDA, Ca and IVDDM. In silage, the DM levels were lower (P < 0.05) than in original material. The values of DM were increased linearly as increased levels of inclusion of TNF. The fibrous components, including NIDN and NIDA, decreased linearly when the TNF increased. In all treatments, values of pH and N-NH3 considered ideal for good silage were observed. The IVDDM was reduced, linearly, with the addition of increasing levels of TNF. A negative correlation (-0.95) between IVDDM and content of EE may explain the tendency of this variable, due to the EE content increased linearly with the addition of TNF. The addition of TNF as an additive in silage of elephant diminished IVDDM. Considering the changes observed in the chemical composition and digestibility of elephant grass silage with TNF as additive, suggests that this should not be included at levels exceeding 3%. On the other hand, the silages with TNF as additive showed appropriate fermentation characteristics.

Omissāo de macronutrientes no crescimento e no estado nutricional de capim-elefante (cv. Mott) cultivado em solução nutritiva

The objective of this work was to evaluate the effect of omission of macronutrients in the growth and the nutritional state of elephant-grass plants (Pennisetum purpureum Shum cv. Mott). The experiment was developed in the FCAV/UNESP, in Jaboticabal-SP,Brazil, using nutrient solution. The experimental design was completely randomized blocks, with seven treatments (the complete solution proposed by Hoagland & Amon (1950) and the individual omission of N, P, K, Ca, Mg and S, in these solution), in three repetitions. Pre-germinated plants were placed in pot (5 dm3), containing the nutrient solution, which was aerated constantly during the experimental period and the respective treatments, with three replications each. Weekly, the height of the plants, the leaf number, apex diameter and number of tillers were evaluated as well as plant nutritional state. The omission of N, P, K, Ca, Mg and S limited the production of dry weight of shoot the elephant grass, compared to the full treatment. The deficiency of a macronutrient, in addition to promoting reduction of its content in the shoot, resulted in reducing the accumulation of most macronutrients, with resultant morphological changes, translated as characteristic symptoms of deficiency.

Consumo de capim-elefante com diferentes idades fornecido para vacas leiteiras

The 30, 45 and 60 day-old elephant grasses were evaluated by monitoring their nutritional profile and DM (DMI) and NDF (NDFI) intake by crossbred lactating cows in a 3 × 3 Latin square trial, where the split-plots were the rumen evacuation times: 0, 2, 4 and 6 h after meal. Chemical composition, in vitro dry matter digestibility and ruminal content ranged with grass age. Means (in kg/cow/day) of DMI and NDFI of 30 day-old grass (8.0 and 5.3) were lower than those of grasses with 45 days (10.0 and 6.6) and 60 days (11.0 and 7.3). The maximum of rumen fill was observed at 4:22, 3:55 and 3:49 hours after feeding for treatments with 30, 45 and 60 day-old elephant grass, respectively. Rumen fill did not limit the DMI and NDFI of elephant grass, but the dry matter intake of 30 day-old grass may be affected by the wet content.

Desenvolvimento e nutrição do capim-Tanzânia em função da aplicação de zinco

It was aimed to assess the effects of zinc in the development and nutrition of Tanzania grass. The experimental design used was fully randomized, consisting of six doses of zinc (0, 15, 30, 60, 120 and 240 mg dm'3) and four repetitions. The experimental unit was formed in a vase filled with a Red Latosol dystrophic (Zn = 0.4 mg dm). There were two cuts, the first after 53 days of transplanting seedlings and the second 35 days after the first cut. Was evaluated the concentration of zinc in the soil, the content of zinc leaf, the number of tillers, number of leaves, plant height, the dry mass of the shoot, root system and the whole plant. The doses of zinc influenced the concentration of zinc in soil and plant, and production of dry mass of Tanzania grass, especially the first cut. The Tanzania grass shows high tolerance to the toxicity of zinc, and toxic critical level of 273 mg kg-1.

Características fotossintéticas de genótipos de capim-elefante anão (Pennisetum purpureum Schum.), em estresse hídrico

The experiment was carried out aiming to evaluate the gas exchange of dwarf elephant grass genotypes under different hydric conditions, in a randomized design with three replications. Genotypes of dwarf elephant grass (Mott, CNPGL 94-34-3 and CNPGL 92-198-7) were analyzed under two hydric conditions: irrigated (I) and non-irrigated (NI). Differences between treatments I and NI were observed for all genotypes for photosynthesis, stomatal conductance, transpiration and water vapor pressure deficit. Genotype CNPGL 94-34-3 presented highest tolerance to hydric stress, followed by Mott and CNPGL 92-198-7 genotypes. All genotypes presented high photosynthetic rate, under ideal conditions of soil humidity, thus characterizing the analyzed dwarf elephant grass genotypes as plants with high photosynthetic efficiency.

Estrutura do capim-braquiária durante o diferimento da pastagem

This experiment was performed aiming to evaluate tiller population density, forage mass and its morphological components on pastures of Brachiaria decumbens cv. Basilisk. during deferment. The treatments encompassed four deferred grazing periods (18, 46, 74 and 121 days). A randomized block design with two replications was used. The numbers of vegetative tillers (VT), reproductive tillers (RT) and dead tillers (DT) in the pasture were determined. The masses of green leaf blade (GLBM), dead stem (DSM) and dead forage (DFM) were also determined. There was a reduction in the number of VT (from 1, 491 to 944 tiller m-2) during the deferment period. RT and DT numbers were not influenced by the deferment periods. Their averages were 211 and 456 tiller m-2, respectively. Longer deferring periods resulted in an increase in GSM (from 2, 965 to 4, 877 kg ha-1 of dry mass) and DFM (from 2, 324 to 4, 823 kg ha-1 of dry mass), but it did not influence GLBM (average of 2, 047 kg ha-1 of dry mass). In Viçosa, Minas Gerais State Brazil, Brachiaria decumbens cv. Basilisk pasture fertilized and deferred in the beginning of March must be kept deferred for about 70 days in order to conciliate both quality and quantity forage production.

Capim-colonião e seus efeitos sobre o crescimento inicial de clones de eucalyptus × urograndis

This study aimed to evaluate the guinea grass effect (Panicum maximum) on the initial growth of different Eucalyptus × urograndis clones. Two assays were established with eucalyptus clones and guinea grass seedlings. The plants were grown in plots with cement borders filled with soil. Each plot received a eucalyptus seedling. The first assay had a completely randomized experimental design, with three replications, and treatments in a 5x2 factorial scheme (five eucalyptus clones and the absence or presence of two guinea grass plants at 10 cm distance from eucalyptus seedling). The second assay was similar to the first, however with three eucalyptus clones. The experimental design was completely randomized, with five replications, and a 3x2 factorial scheme (three eucalyptus clones and the absence or presence of two guinea grass plants). The presence of eucalyptus clones did not affect guinea grass development. The eucalyptus clones that coexisted with guinea grass plants did not show differences in their development, making the clones equal when under competition. The most susceptible characteristics of eucalyptus clones to guinea grass were foliar area, shoot and stem dry matter. Clone 3 showed the most sensitivity to guinea grass, and clone 1 was the most tolerant, but all clones studied suffered a negative interference from guinea grass.

Número de perfilhos do capim-braquiária em regime de lotação contínua

The study was conducted to identify, through assessments of tillering, appropriate management strategies for Brachiaria decumbens cv. Basilisk under continuous stocking with cattle. Two management strategies were studied: pasture with 25 cm throughout the experimental period, and pasture with 15 cm in winter and 25 cm in spring and summer. A split-plot and randomized block design with four replications were adopted. The management strategies represented the primary factor, and the seasons (winter, spring and summer) were the secondary factor. The lowest balance between rates of appearance (TAR) and mortality (TMR) of tillers and the lowest number of vegetative tillers occurred in winter. In spring and summer, the balance and number of vegetative tillers were higher and did not differ. The lowering of pasture in winter resulted in greater balance between TAR and TMR and higher number of tillers in relation to management on sward fixed at 25 cm. There were greater numbers of reproductive and dead tillers in summer and winter, respectively. The pastures with fixed height of 25 cm contained a higher number of dead tiller. Under continuous stocking, the lowering of B. decumbens pasture in winter and its increase to 25 cm in spring and summer optimizes turnover of tillers.

Perfil Fermentativo e Valor Nutritivo de Silagem de Capim-Elefante Inoculada com Streptococcus Bovis

The experiment was developed to evaluate the effect of strains of Streptococcus bovis (HC5 and JB1) on pH, ammonia production and nutritional value in elephant-grass silages (Pennisetum purpureum Schum). The experimental design was entirely randomized, with three treatments: T1 - elephant- grass, T2 - grass-elephant inoculated with Streptococcus bovis HC5, T3 - elephant grass inoculated with Streptococcus bovis JB1, totaling five replicates per treatment. The smallest value of ammonia was observed in the silage treated with inoculante the base Streptococcus bovis JB1 (5.90% N-total). Inoculation increased the levels of lactic acid and decreased levels of acetic, propionic and butyric acids, and the silages inoculated with Streptococcus bovis JB1 and HC5 were those with the highest values of lactic acid. There were not statistical differences for the tenors of dry matter (MS) and crude protein (PB). For the values of the fibers, the grass-elephant silage inoculated with Streptococcus bovis JB1, it presented the smallest value of neutral detergent fiber (59.77 %) and Hemicellulose (26.71 %). The largest value of in vitro dry matter digestibility (DIVMS) was observed in the silage with Streptococcus bovis JB1, showing superiority of four percentile points (64.23 %) in relation to the treatment without bacterial inoculante (60.35 %). The use Streptococcus bovis JB1 was efficient in the process fermentativo besides promoting would get better in the quality of the fiber and DIVMS in the studied silage.