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Os ionóforos atuam na manipulação da fermentação ruminal e podem aumentar a eficiência alimentar, melhorando a performance animal. E são oriundos da fermentação de algumas espécies de Streptomyces. Os ionóforos são classificados como substâncias capazes de interagir passivamente com íons, cátions, servindo, desta forma, como um veículo de transporte para estes através de membranas celulares. Atualmente são conhecidos alguns tipos de ionóforos, destacando-se a Monensina, Salinomicina, Lasalocida e Narasina. Objetivou-se, a partir desta revisão abordar os resultados apresentados na literatura sobre o uso de ionóforos e outros aditivos na nutrição de ruminantes, e esclarecer o papel destes na fermentação ruminal, consumo, digestão e aplicações práticas nos sistemas de produção.

The carbon (C) and nitrogen (N) contents of the soil, when associated through the C:N ratio, make it possible to obtain indices that reveal the quality of soil organic matter (OM), as well as the decomposition efficiency, conversion efficiency of carbon and organic nitrogen into their mineral forms, and the dynamics of these nutrients in the soil. According to the literature, the C:N ratio can be between 30 - 100 in native forest areas and 20 - 30 in cultivated areas. The objective of this work was to evaluate the relationship between soil carbon and nitrogen in integrated systems, monoculture pasture, and native Cerrado forest. Undeformed soil samples were collected once at a site located in the municipality of Barbacena, MG, at depths 0-5 cm, 5-10 cm, 10-20 cm and 20-30 cm in four distinct areas, designated as treatment 1: pasture monoculture (MP) of Urochloa decumbens cv. Basilisk with 27 years of plantation; treatment 2: grass-legume combination (GLC), composed of Urochloa decumbens cv. Basilisk and Arachis pintoi cv. Amarillo with 25 years of plantation; treatment 3: silvopastoral system (SSP), composed of Eucalyptus urophylla planted 13 years ago in an area where Urochloa decumbens cv. Basiliskwas was already established for 14 years; and treatment 4: native forest (NF) of the Cerrado biome with 37 years of regeneration. The quantification of total organic C was performed according to the method proposed by Yeomans and Bremmer (1988); and the determination of total N was performed as proposed by Bremner and Mulvaney (1982) and adapted by Mendonça and Matos (2005). The experimental design completely randomized, with five replications in each treatment. The data were submitted to statistical analysis using the Kruskall-Wallis test and Dunn's test. The NF system showed the highest C:N ratio at all evaluated depths (32.3 – 40.6), being statistically similar to MP (30 – 37) and SSP (25.5 – 28.5). The CGL system did not show statistical similarity with MP and FN, but it was equal to SSP (p

Integrated production systems can stimulate the growth and reproduction of soil microbiota responsible for nutrient cycling. The use of quality indicators such as soil microbial biomass carbon (SMBC) can help formulate strategies that preserve organic matter and enable more sustainable production systems. The objective of this study was to evaluate soil microbial biomass carbon in integrated production systems, a monoculture system of pasture, and native Cerrado forest. Undeformed soil samples were collected at a site located in the municipality of Barbacena, MG, at depths 0-5 cm, 5-10 cm, 10-20 cm and 20-30 cm in four distinct areas, formed by treatment 1: monoculture to pasture (MP) of Urochloa decumbens cv. Basilisk; treatment 2: combination of legumes and grasses (CLG) composed of Urochloa decumbens cv. Basilisk and Arachis pintoi cv. Amarillo, with a history of conventional cultivation; treatment 3: silvopastoral system (SSP), composed of Urochloa decumbens cv. Basilisk and Eucalyptus urophylla; and treatment 4: native forest (NF) of the Cerrado biome, with 37 years of regeneration. To determine the carbon in the biomass, the fumigation-extraction method proposed by Vance et al. (1987) was applied, with fumigation and the addition of chloroform (without alcohol) in the sample, as suggested by Brookes et al. (1982) and Witt et al. (2000). The experimental design was completely randomized, with five replications in each treatment. The data obtained were submitted to statistical analysis using the Kruskall-Wallis test and Dunn's test. The microbial biomass carbon reached the lowest level in CLG and highest in FN, with statistical differences in the deeper layers and no statistical difference just in the surface layer (0-5cm). MP and SSP treatments did not differ from FN. In the CLG system, the results found corresponded to 153.1, 152.9, 132.6, 91.3 in layers 0-5, 5-10, 10-20 and 20-30 respectively, while in the FN system, the values were 295. 7, 265.5, 235 and 235 in the corresponding layers. The CLG system contained on average 49% less carbon in the microbial biomass compared to NF, while the silvopastoral system averaged 8%, and the pasture monoculture had a 12% difference. The higher carbon content of the microbial biomass in the areas of native vegetation, silvopastoral system and monoculture pasture may be a reflection of the continuous supply of organic materials from the litter and rhizosphere, associated with the absence of soil disturbance, constituting a favorable factor for survival and growth of different groups of microorganisms; while the low SMBC in CLG can be explained by the rapid decomposition of organic matter, which has low C:N ratio, and also can be associated with lower litter deposition, limiting microbial activity. Since there was no difference in CBMS between treatments in the 0-5 cm layer, where there is a greater predominance of Arachis pintoi roots, we infer that the fibrous root component present in SSP, MP and NF substantially contributed to the growth of microbial biomass in the subsurface soil layers, providing these systems with better nutrient cycling.

Abstract The objective of this work was to evaluate the effects of the inclusion of pelleted citrus pulp and microbial inoculant on the fermentation characteristics, carbohydrate and protein fractionation, and total digestible nutrient contents of 'Massai' grass (Megathyrsus maximus × Megathyrsus infestus) silage. The experimental design was completely randomized, in a 2×4 factorial arrangement (application or not of inoculant × 0, 10, 20, and 30% citrus pulp) with five replicates. There was an increase in dry matter recovery as affected by citrus pulp levels. The values obtained for pH and ammonia nitrogen indicated an adequate fermentation process. Under increasing citrus pulp levels, there was a reduction in neutral detergent fiber and an increase in nonfibrous carbohydrate contents and in protein linked to fiber. Total digestible nutrient content reaches a peak of 513.1 g kg1 with the inclusion of 12.50% citrus pulp. The microbial inoculant, when isolated, does not influence carbohydrate and protein profiles. Inclusions between 10 and 20% citrus pulp are able to maintain adequate fermentative parameters and improve the digestible nutrient profile, with an adequate dry matter recovery.

The research submitted samples from stems and leaf blades from tree genotypes of Pennisetum purpureum called 93-32-02, 92-70-02, and 91-06-02 (EMBRAPA - Dairy cattle) and elephant grass cv. Napier (reference cultivar) to the chemical, anatomical evaluations, and in vitro dry matter digestibility (IVDMD) measurement. The anatomical characteristics of the stems and leaf blades, the chemical composition, and the IVDMD of these genotypes at 70 days of re-growth were correlated. Concerning IVDMD, the data highlighted differences, and the cultivar Napier presented the smallest value. Digital images obtained by light microscopy from cross-section reveal that all the stem and leaf blade have similar structural organization. Quantitative differences were verified mainly in the stem. The leaves displayed differences only in the mesophyll thickness. The genotypes showed higher potential in the rainy season since they had the largest IVDMD when compared to the cultivar Napier.

The aim of this study was to evaluate the effect of ammoniation by urea on the nutritional value of elephant grass hay harvested after flowering. A completely randomized design, in double factorial designs with an additional treatment: 4 urea doses (2, 4, 6 and 8%) x 2 treatment periods (30 and 45 days) + 1 (Control) with four replicates each, was employed. Dry matter, ash, ether extract, neutral detergent fiber, acid detergent fiber, cellulose, lignin, neutral detergent fiber corrected for the ash and the protein, total nitrogen, acid detergent insoluble nitrogen, neutral detergent insoluble nitrogen, non-protein nitrogen, in vitro gas production and carbohydrates fractionation were analyzed. The treatments influenced the contents of DM, EE, NDF, ADF, lignin, cellulose, NDFap, fraction A + B1, fraction B2, fraction C, TN, NPN, ADIN, NDIN, L and Vf2. There was a positive linear effect of urea dose for NDF, ADIN, NDIN and L, positive linear effect on fraction A + B1, NT and NPN, and positive quadratic effect for Vf2, with absolute maximum point of 4.5%. Elephant grass hay harvested after flowering has its nutritional value improved, with a minimum dose of 4.5% urea on a dry matter basis.

Abstract: The objective of this work was to characterize condensed tannins (CT) from six tropical forage legumes and to determine their biological activity. The monomers propelargonidin, prodelphinidin and procyanidin were analyzed, as well as extractable condensed tannin (ECT), protein-bound CT (PBCT) and fiber-bound CT (FBCT), molecular weight, degree of polymerization, polydispersity index, and biological activity by protein precipitate by phenols (PPP) of leaves of the legumes Cajanus cajan, Gliricidia sepium, Stylosanthes capitata x Stylosanthes macrocephala (stylo), Flemingia macrophylla, Cratylia argentea, and Mimosa caesalpiniifolia, and of the bark of this latter species. Differences were observed in the concentrations of ECT, PBCT, PPP, and total condensed tannin among species, but not in that of FBCT. The highest value of PBCT occurred in F. macrophylla. Total CT varied from nondetected concentration in C. argentea to the highest concentration in M. caesalpiniifolia leaves that contain the greatest levels of PPP. No differences were observed for polymerization degree in stylo, F. macrophylla, and M. caesalpiniifolia. Leaves of stylo, C. cajan, and G. sepium, all containing between 20 and 50 g kg-1 total CT, should be beneficial CT sources, if offered as sole feeds in ruminant diets. The ratio of prodelphinidin:procyanidin varies from 10:80 (stylo) to 65:35 (F. machrophylla), and propelargonidin is only determined in C. argentea.

The effects of nitrogen (N) dose and urea source on forage mass (FM), percentage of dry matter of leaf blades (LBDMP), stem (SDMP), and dead material (DMDMP), and the forage accumulation rate (FAR) of Panicum maximum ‘Massai’ (massai grass) were evaluated. We set up an experiment with a completely randomized block design in a factorial arrangement (3×2) + 1, consisting of three doses (100, 200, and 400 kg ha–1 year–1), two urea sources (common and coated with Policote®), and a control treatment, in five consecutive climatic seasons, including the summers of 2011/2012 (summer I), autumn, winter, and spring of 2012, and the summers of 2012/2013 (summer II). We found an interaction effect between N dose, urea source, and season (p < 0.05). LBDMP linearly increased during dry periods (autumn and winter) and SDMP in autumn and DMDMP in winter linearly decreased when coated urea were used. FAR showed a linear increase with the use of both urea sources, except for common urea in autumn, and the increases in the winter were owing to a greater contribution of leaf blades to FM. The use of coated urea for N fertilization linearly increases FAR in all seasons of the year and improves the morphological composition of the forage of massai grass, mainly in dry seasons.

Abstract: The objective of this work was to evaluate the effect of the addition of the methanolic extract of Urochloa humidicola at four different concentrations (0, 75, 150, and 250 g L-1) on the in vitro rumen fermentation of Urochloa brizantha. The following variables were evaluated by the in vitro gas production technique: kinetic parameters; rumen degradation of dry matter; and production and concentration of the methane and carbon dioxide gases and of the acetate, propionate, and butyrate short-chain fatty acids. The addition of the methanolic extract reduces the production of gases generated from the degradation of non-fibrous carbohydrates (fraction A) in 9.55, 6.67, and 13.33%, respectively, at the concentrations of 75, 150, and 250 g L-1, compared with the control group, but it negatively affects the degradation of the dry matter of U. brizantha at the concentrations of 150 and 250 g L-1. The extract shows negative quadratic effect on gas production during 12 and 24 hours of U. brizantha incubation. The extract of U. humidicola reduces methane production and increases short-chain fatty acid production at the concentrations of 75, 150, and 250 g L-1.

Abstract: The objective of this work was to evaluate the use of soybean (Glycine max), pigeon pea (Cajanus cajan), and jack bean (Canavalia ensiformis) as urease sources for elephant grass (Pennisetum purpureum) hay ammoniated with urea. The experimental design was completely randomized in a double factorial arrangement with one additional treatment: 4 urease source levels x 3 urease sources + 1 control. Chemical-bromatological analyses and carbohydrate fractionation were performed in the hay, and cumulative gas production in vitro was determined. There were interactions between urease level and source for neutral detergent fiber and acid detergent fiber, in which 1 and 2% jack bean lowered acid detergent fiber values, and 2% jack bean and 3% soybean reduced lignin content. The addition of milled legume grains reduces fiber components and increases non protein nitrogen content in elephant grass hay ammoniated with urea. Adding 4% milled soybean increases gas production in the soluble fraction.

Abstract: The objective of this work was to evaluate the variations in root dry matter mass (RDM) and the percentage distribution (PD) of the root density of Florico grass (Cynodon nlemfuensis) in the 0-40-cm soil layer, when managed under different grazing strategies. Two defoliation frequencies (90 and 95% light interception, as the criterion for allowing animals in the paddock) and two defoliation severities (post-grazing heights of 20 or 30 cm) were assessed. Four seasonal evaluations of the root system were performed between the winter of 2012 and the autumn of 2013, using the monolith and trench excavation technique, collecting 1-dm3 samples from soil surface down to a depth of 40 cm, in four sequential extracts of 10 cm each. Lower RDM values (0.69 g dm-3) were obtained in winter, with the four grazing strategies, whereas higher values were observed in spring (1.64 g dm-3), for the 30-cm post-grazing residue, and in autumn (1.63 g dm-3) for the 20 cm post-grazing residue, regardless of the light interception value. Between 52 and 66% of the RDM density was observed in the 10-cm layer, for all four grazing strategies, in all seasons.

This study aimed to evaluate the shading influence on production and qualitative traits of four tropical forage legumes (calopo, puero, archer and perennial soybean). Legumes were cultivated under levels of artificial shading (0; 30; 50 and 70%) from January 2006 to June 2007. Dry matter production (DM), crude protein (CP), neutral detergent fiber (NDF), cellulose (CEL), hemicellulose (HEM) and lignin contents were evaluated. In the summer, increases in legumes DM yield were observed when grown under increasing shading levels. Calopo, puero, and archer production showed quadratic effect. Regression analysis derivation for dry matter yield showed levels of maximum values at 35.0; 33.78 and 45.45% in the summer and 34.94; 34.83 and 33.29% in the fall. Significant effect of species for CP, NDF, CEL, HEM and L/S (leaf/stem) ratio and shading level effect for NDF, CEL, HEM and L/S ratio were observed in the summer, however, no interaction was reported. In addition, significant effect of species for CP, NDF, CEL, HEM and L/S ratio was observed in the autumn. Only L/S ratio presented a negative response according to increasing shading levels. The shading promoted an increase in the fiber components and a decrease in the leaf/stem ratio, and the perennial soybean was the most tolerant to the increased shading.

The effect of ammonization was evaluated with urea at doses of 1, 2, 3 and 4%, on the basis of dry matter (DM) on Tifton 85 hay harvested at an advanced stage of development in the periods of 30 and 45 days, through analysis of dry matter, ash, ether extract (EE), neutral (NDF) and acid (ADF) detergent fiber, NDF corrected for ash and protein (NDFap), cellulose, lignin, crude protein (CP), acid detergent insoluble nitrogen (ADIN), fractionation of carbohydrates and in vitro gas production (Parameters: Vf1, k1, Vf2, k2 and L). The variables DM, EE, NDF, ADF, lignin, cellulose, NDFap, fraction A + B1, fraction B2 and C of carbohydrates, and the Vf1 and Vf2 parameters were influenced by treatments (p < 0.05). While DM, NDF, NDFap, fraction A + B1, C, CP and Vf2 showed linear effects according to the dose, NIDA and hemicellulose presented quadratic effects. Vf1 and Vf2 were also influenced by the treatment period. The ammonization with 2.7% urea on the basis of DM promotes improvement of Tifton 85 hay treated for 45 days, observed after derivation of the regression equation and evaluation of the nutritional and kinetic degradation in vitro.

Avaliou-se a eficiência de doses de nitrogênio (N) e fontes de ureia sobre as variáveis massa de forragem (MF), porcentagens de massa seca de lâminas foliares (PMSLF), colmos (PMSC) e de material morto (PMSMM), além da taxa de acúmulo de forragem (TAF) do Panicum maximum cv. Massai (capim Massai). Para tanto, delineou-se um experimento em blocos completos casualizados, em arranjo fatorial (3x2) + 1; constando de três doses de N (100, 200 e 400 kg ha-1 ano-1), duas fontes ureia (comum e revestida com Policote®) e um tratamento controle, em cinco estações climáticas consecutivas, verão de 2011/2012 (verão I), outono, inverno e primavera de 2012, e verão de 2012/2013 (verão II). As variáveis analisadas apresentaram efeito de interação entre dose de N, fonte de ureia e estações do ano (p < 0,05). Houve aumento linear da PMSLF durante o período seco (outono e inverno) e redução linear da PMSC no outono e da PMSMM no inverno para o uso da ureia revestida. As TAF apresentaram aumento linear com uso de ambas às fontes de ureia, exceto para ureia comum no outono, e aquelas obtidas durante o inverno ocorreram em função das maiores participações de lâminas foliares nas MF. O aumento da adubação nitrogenada com ureia revestida aumenta de forma linear positiva a taxa de acúmulo de forragem em todas as estações do ano e melhora a composição morfológica da forragem do capim Massai, principalmente em estações com déficit hídrico.

The objective of this study was to evaluate the composition of calcium, phosphorus and potassium, and the leaf: stem ratio of four tropical forage legumes: Calopogonium mucunoides (calopo), Pueraria phaseoloides (puero), Macrotyloma axillare (archer) and Neonotonia wightii (perennial soybean), under different levels of artificial shade (0, 30, 50 and 70%) in the summer and autumn seasons of 2006 and 2007, respectively. The experimental design was a randomized complete block in factorial 4x4 design with four replications. Was used SNK test at 5% probability to evaluate the effect of the legume species and regression analysis to test the effect of the level of shading. There was a trend of increase in the concentration of 3 independent minerals examined the season. In contrast, there was a reduction in the leaf: stem ratio and a slight increase in specific leaf area archer, perennial soybean and puero (R2 ? 40%), which suggests small effect of shading on the morphology of leaves of 3 forage legumes, which in turn have little effect concentrating minerals, besides these finding is confirmed the annual calopo behavior, which prevents their use as legume forage for the autumn season.

This survey aimed to characterize a Urochloa humidicola methanol extract regarding the presence of secondary metabolites classes and to determine its bromatological composition. U. humidicola samples were dried under shade, milled on a 2-mm sieve by a Willey mill. The solution obtained was filtered using filter paper and concentrated in a rotary evaporator under reduced pressure; the concentrated residue was then placed in an open vessel to complete solvent removal using continuous air flow dryers. Phytochemical prospection tests and bromatological composition analyses were performed on the dry methanol extract, and the results were compared to in natura U. humidicola. The methanol extract had 10.2% CP and 35% EE and in natura U. humidicola had 5.17% CP and 1.57% EE, with a difference (P < 0.05) of 5% by Fisher's test. In natura U. humidicola had 75.59% NDF, 40.77% ADF, 38.82% HEM, 29.93% CEL, and 7.19% LIG. Methanol extraction by cold maceration reduced the LIG (0.17%) and CEL (0.21%) contents as only soluble constituents were extracted. A phytochemical assay was positive for the presence of saponins, tannins, alkaloids, non-protein amino acids, carbohydrates, cardiac glycosides, steroids, tripernoids, catechins, and saccharides and was negative for the presence of flavonoids and purines. The U. humidicola methanol extract possesses traits that allow its use as a phytogenic and natural additive.

The objective of this work was to evaluate the use of citrus pulp addition and wilting on fermentative characteristics, chemical composition as well as gas and effluent losses of elephant grass silage. The elephant grass (70 growth days) was collected manually; one portion was immediately chopped and another one was allowed to wilt in the sun for a period of 6 h and subsequently chopped for the production of silage. Experimental PVC silos (10 cm diameter x 30 cm height) were used and sand bags were placed at the bottom of the silos. Citrus pulp (80 g kg-1 of MN) was added at the beginning of ensilage. The ensiled material was manually compressed to provide a specific mass of approximately 600 kg m-3 of silage. After 60 days, the silos were opened; gas and effluent losses were calculated and we determined pH, dry matter (DM), crude protein(CP), neutral detergent fibre (NDF), lignin, ammonia nitrogen, ash and in vitro dry matter digestibility (IVDMD). We added 0 or 80 g kg-1 of citrus pulp to wilted and un-wilted elephant grass. We used a completely randomised design with a 2 x 2 factorial arrangement (wilted or un-wilted) x (with or without citrus pulp), totalling treatments with five repetitions. Average values were compared using the F test with a probability of 5%. The addition of citrus pulp resulted in reduced levels of NDF, lignin, ash, N-NH3 and pH and in increased values of DM and IVDMD of silages. Wilting increased the DM, NDF and lignin values and reduced the concentrations of CP, IVDMD and N-NH3. Based on our results, citrus pulp addition improves the chemical composition of elephant grass silage and increases its in vitro dry matter digestibility.

The objective of this trial was to evaluate the behavior ingestive of crossbred heifers and chemical characteristics of the material from two clones of dwarf elephant grass (BRS Kurumi ‘and CNPGL 01/03/00) submitted to different management strategies through sampling of forage (whole plant extrusa and manual hand plucking. The experiment was conducted at Embrapa Dairy Cattle, Coronel Pacheco, MG. We used a completely randomized design with factorial (2x2x2) with three replications. The treatments consisted of two clones of elephant grass (BRS Kurumi ‘and CNPGL 01/03/00), two light interception at the entrance of the animals (90 and 95%) and two heights of post-grazing residue (30 and 50 cm) with three replications. The chemical analysis showed that the methodology manual grazing simulation enables an acceptable estimate of the forage selected by grazing animals and the sampling of the whole plant is not selected by the animal diet. To harvest extrusa rate evaluation and mass bit, fractions and chemical composition of the plant of the ingested material was taken. Characteristics, structural and nutritional value of clone BRS ‘Kurumi’ facilitated greater forage intake by the animal, suggesting its use in grazing systems.

The objective of this study was to identify secondary metabolite classes of tropical kudzu, perennial soybean and archer legumes through identification by phytochemical screening and confirmation by infrared (IR), ¹H and carbon-13 NMR spectroscopy of fractions obtained by organic solvents partition of crude extracts. These analyses allowed for proposing the presence of the following metabolite classes: reducing sugars, saccharides, saponins, cardiac glucosides, terpenes, coumarins, tannins, alkaloids and flavonoids. The tannins, saponins, alkaloids, organic acids and flavonoids had special consideration because they are toxic compounds and can affect the animal metabolism.

This experiment was carried out to evaluate the effects of proteic-energetic supplementation for Red Angus x Nellore steers raised on Brachiaria purpurascens (Henr. Blumea) tropical pastures during the wet season. Thirty-two steers were used to form four groups containing eight animals each. The experimental treatments were: (1) control (commercial mineral mix); (2) concentrate (concentrate ration, formulated to ensure a gain of 1.10 kg/day), and (3) proteic-energetic supplement containing whether corn (SCC) or (4) wheat midllings (SCWM). Daily weight gain, supplement intake, income over feed costs and the frequency of water trough access were assessed. The supplement intake was 0.076, 2.77, 0.74 and 0.86 kg/steer/day for the control, concentrate, SCC and SCWM groups, respectively. There were no differences in the daily weight gain amongst the control, SCC and SCWM groups and the concentrate group had the highest daily weight gain. The animals that received SCC had the highest income over feed costs and the concentrate group had the lowest one. Proteic-energetic supplementation during the wet season can, numerically, improve the daily weight gain, but this nutritional strategy must be done with caution to avoid economic losses.

Entre os fatores determinantes da baixa utilização do consórcio gramínea-leguminosa, pode ser citado a implantação das leguminosas em pastagens já estabelecida. No entanto, animais podem servir como mecanismo de dispersão das sementes. Assim, objetivou-se neste estudo avaliar a introdução das leguminosas calopogônio, macrotiloma, kudzu tropical e soja perene em pastagem estabelecida de Brachiaria decumbens, por meio da dispersão em fezes de bovinos. Para esta finalidade, foi utilizado cinco novilhas como veiculadoras das sementes, as quais foram ofertadas 180g de sementes de cada leguminosa misturado ao concentrado de forma alternada, esperando um período de 48h para completa defecação das sementes. Todas as leguminosas foram encontradas nas placas fecais, porém o kudzu apresentou maior número de exemplares encontrados em relação às demais (P

Foi desenvolvido um experimento para avaliar o efeito da adição de três níveis de soro de queijo (0%, 2,5% e5,0% na matéria natural) sobre a composição bromatológica, pH, N-amoniacal, perdas de gás, efluente e recuperação da matéria seca de silagem de capim-elefante (Pennisetum purpureum cv. Napier). O delineamento foi o inteiramente casualizado com três tratamentos e quatro repetições por tratamento. Efetuou-se um corte de uniformização do capim, seguido de uma adubação com 60 kg de N/ha, na forma de uréia, sessenta dias após, efetuaram-se o corte e a ensilagem do capim, em baldes experimentais com capacidade de 6,5 litros. Avaliaram-se o teor de matéria seca, o pH, o N-amoniacal, proteína bruta, fibra em detergente neutro e fibra em detergente ácido das silagens. Os teores de FDN e FDA não sofreram influência da adição do soro. O soro foi eficiente em reduzir as perdas por gases e a produção de N-amoniacal, todavia aumentou as perdas por efluente. Não houve influência da adição do soro sobre o pH e recuperação da matéria seca. A silagem é uma alternativa para utilização de soro produzido pela indústria de laticínios. PALAVRAS–CHAVE: Conservação, N-amoniacal, pH.

Este trabalho tem o objetivo de demonstrar os resultados de pesquisa realizada junto a 250 pecuaristas leiteiros, com questões relacionadas a aspectos sócio-econômicos dos produtores de leite brasileiros. Esta pesquisa fez parte do Projeto Alfa NERUDA (www.alfa-neruda.com) trabalho financiado pela Comunidade Econômica Européia, com a participação de cinco países da América Latina e quatro países da Europa. O questionário que foi aplicado na pesquisa, também foi utilizado em pesquisa semelhante junto aos produtores dos outros países. Os resultados encontrados no Brasil foram os seguintes: Faixa etária entre 51 e 65 anos (39,2%), 82,0% são casados, 62,3% residem nas propriedades, 18,8% tem filhos trabalhando na atividade, 100% tem luz elétrica, 68,8% são atividades familiares, 32,4% tem outras atividades econômicas, 71,2% comercialização seu leite para cooperativas, 25,7% para laticínios, 3,1% fazem venda direta ao consumidor, 58,3% consideraram que o custo de seu litro de leite estava entre R$0,31 (US$0,14) a R$0,50 (US$0,23), 89,8% usam tanque de expansão, 12,8% fazem remuneração especial aos ordenhadores, 14,0% controlam resíduos, 1,6% fazem rastreabilidade do rebanho, 44,0% tem a pecuária de corte como outra atividade, 68,8% das propriedades tem menos de 100ha, 65,4% tem menos de 50 vacas no rebanho, 56,3% produzem menos de 200 lts/dia.

Este trabalho tem o objetivo de demonstrar os resultados de pesquisa realizada junto a 250 pecuaristas leiteiros, com questões relacionadas a aspectos sócio-econômicos dos produtores de leite brasileiros. Esta pesquisa fez parte do Projeto Alfa NERUDA (www.alfa-neruda.com) trabalho financiado pela Comunidade Econômica Européia, com a participação de cinco países da América Latina e quatro países da Europa. O questionário que foi aplicado na pesquisa, também foi utilizado em pesquisa semelhante junto aos produtores dos outros países. Os resultados encontrados no Brasil foram os seguintes: Faixa etária entre 51 e 65 anos (39,2%), 82,0% são casados, 62,3% residem nas propriedades, 18,8% tem filhos trabalhando na atividade, 100% tem luz elétrica, 68,8% são atividades familiares, 32,4% tem outras atividades econômicas, 71,2% comercialização seu leite para cooperativas, 25,7% para laticínios, 3,1% fazem venda direta ao consumidor, 58,3% consideraram que o custo de seu litro de leite estava entre R$0,31 (US$0,14) a R$0,50 (US$0,23), 89,8% usam tanque de expansão, 12,8% fazem remuneração especial aos ordenhadores, 14,0% controlam resíduos, 1,6% fazem rastreabilidade do rebanho, 44,0% tem a pecuária de corte como outra atividade, 68,8% das propriedades tem menos de 100ha, 65,4% tem menos de 50 vacas no rebanho, 56,3% produzem menos de 200 lts/dia.

O presente trabalho foi desenvolvido no Sítio Campo Alegre em Barbacena-MG para avaliar, a produção de massa verde (MV), teor (% MS) e produção de matéria seca (PMS), características morfológicas: acamamento, despalha, altura das folhas e colmo da cana planta e as características de maturação obtidas através do % Brix médio, das diferentes alturas e o Ãndice de Maturação no período de 1,25 anos, de seis cultivares de cana-de-açúcar, sendo: IAC 86-2480 e IAC 86-2210 (precoces), RB 72-454 e IAC 93-6006 (médias), SP 81-3250 e IAC 87-3396 (tardias). O experimento foi estabelecido sob o delineamento estatístico de blocos casualizados em uma unidade experimental constituída de quatro linhas com seis metros de comprimento e espaçadas de 0,8m. As maiores produções de MV foram obtidas com as cultivares RB 72-454 (143,72t ha-1) e IAC 87-3396 (136,81t ha-1) e as cultivares precoces apresentaram produções inferiores a 52t ha-1, e as PMS apresentaram comportamento semelhante ao da MV. Os teores de FDN foram inferiores a 40% e o menor valor para a cultivar IAC 87-3396. Os teores de PB foram inferiores a 1,87%. Ao avaliar o conjunto de características morfológicas pode-se inferir que a cultivar IAC 87-3396 apresenta melhor comportamento, além da elevada produção. A análise de graus Brix não mostrou diferença entre as cultivares e valores inferiores a 13%, indicando uma baixa concentração de sacarose. Avaliando-se o brix nas três alturas do colmo pudemos inferir que as cultivares tardias mostraram declínio de maturação; as de maturação média e a IAC 86-2210 (precoce) com adequada maturação e a IAC 86-2480 com média maturação.

O presente trabalho foi desenvolvido no Sítio Campo Alegre em Barbacena-MG para avaliar, a produção de massa verde (MV), teor (% MS) e produção de matéria seca (PMS), características morfológicas: acamamento, despalha, altura das folhas e colmo da cana planta e as características de maturação obtidas através do % Brix médio, das diferentes alturas e o Ãndice de Maturação no período de 1,25 anos, de seis cultivares de cana-de-açúcar, sendo: IAC 86-2480 e IAC 86-2210 (precoces), RB 72-454 e IAC 93-6006 (médias), SP 81-3250 e IAC 87-3396 (tardias). O experimento foi estabelecido sob o delineamento estatístico de blocos casualizados em uma unidade experimental constituída de quatro linhas com seis metros de comprimento e espaçadas de 0,8m. As maiores produções de MV foram obtidas com as cultivares RB 72-454 (143,72t ha-1) e IAC 87-3396 (136,81t ha-1) e as cultivares precoces apresentaram produções inferiores a 52t ha-1, e as PMS apresentaram comportamento semelhante ao da MV. Os teores de FDN foram inferiores a 40% e o menor valor para a cultivar IAC 87-3396. Os teores de PB foram inferiores a 1,87%. Ao avaliar o conjunto de características morfológicas pode-se inferir que a cultivar IAC 87-3396 apresenta melhor comportamento, além da elevada produção. A análise de graus Brix não mostrou diferença entre as cultivares e valores inferiores a 13%, indicando uma baixa concentração de sacarose. Avaliando-se o brix nas três alturas do colmo pudemos inferir que as cultivares tardias mostraram declínio de maturação; as de maturação média e a IAC 86-2210 (precoce) com adequada maturação e a IAC 86-2480 com média maturação.

Foi desenvolvido um experimento para avaliar o efeito da adição de três níveis de soro de queijo (0%, 2,5% e5,0% na matéria natural) sobre a composição bromatológica, pH, N-amoniacal, perdas de gás, efluente e recuperação da matéria seca de silagem de capim-elefante (Pennisetum purpureum cv. Napier). O delineamento foi o inteiramente casualizado com três tratamentos e quatro repetições por tratamento. Efetuou-se um corte de uniformização do capim, seguido de uma adubação com 60 kg de N/ha, na forma de uréia, sessenta dias após, efetuaram-se o corte e a ensilagem do capim, em baldes experimentais com capacidade de 6,5 litros. Avaliaram-se o teor de matéria seca, o pH, o N-amoniacal, proteína bruta, fibra em detergente neutro e fibra em detergente ácido das silagens. Os teores de FDN e FDA não sofreram influência da adição do soro. O soro foi eficiente em reduzir as perdas por gases e a produção de N-amoniacal, todavia aumentou as perdas por efluente. Não houve influência da adição do soro sobre o pH e recuperação da matéria seca. A silagem é uma alternativa para utilização de soro produzido pela indústria de laticínios. PALAVRAS–CHAVE: Conservação, N-amoniacal, pH.

ABSTRACT: Find shade-tolerant species is essential to the success of silvopastoral systems, increasingly frequent in recent years. In legumes, which have potential of biological nitrogen fixation, there is a great lack of knowledge when in shaded environments.The cultivation of four tropical forage (Neonotonia wightii, Pueraria phaseoloides, Macrotyloma axilare and Arachis pintoi) was evaluated when submitted to artificial shade levels (30, 50 and 70% shade) and in full sun during water and drought seasons. The design used was in randomized complete blocks in a sub-divided plot scheme with four replications. In the Water-season the Forage Peanuts had higher forage production in full sun (11 ton ha-1 DM), and under shade did not differ from Perennial Soybean, higher than the others in all levels of shade. In Drought-season the forage production was 61% lower than in Water-season. The highest crude protein levels were reported in Forage Peanuts, Tropical Kudzu and Perennial Soybean, 19.0; 18.3 and 18.2% respectively in the Water-season. Forage Peanuts is a good option for use in silvopastoral systems although there is a small reduction in forage production (average of 23.7%). In general, species of fabaceae showed a greater reduction in forage production in the period of water deficit; however, shading at levels of 30% to 50% contribute to mitigation of water shortage. Although, there is a small reduction in forage production, withexception of perennial soybeans in dry season, it is advisable to use tropical forage legumes in silvopastoral systems, since forage quality is not affected by shade.