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Our objective was to measure chemical composition and anatomy of 5 Megathyrsus maximus (syn. Panicum maximum) genotypes, when grown in combination with eucalypts in a silvopastoral system. Cultivars Massai, Mombaça, BRS Tamani, Tanzânia and intraspecific hybrid accession PM44 were evaluated in full sun and a silvopastoral system at 5 different distances from eucalyptus tree rows. The experimental design was a randomized block in split plot with 2 replications. Plots corresponded with genotypes and subplots with sampling points within the system. Total forage and leaf biomass as well as nutritive value und tissue proportions were evaluated. Our results showed a decrease in biomass as radiation incidence decreased. Forage biomass was greatest in BRS Tamani and Mombaça and lowest in PM44. There was a significant interaction between sampling points and genotype for nutritive value variables, such as crude protein, in vitro digestibility of organic matter, cellulose, hemicellulose and lignin-S, while tissue proportions were not affected by the interaction between sampling points and genotypes. Genotype had more pronounced effects on chemical composition and anatomical characteristics than did sampling points. The leaves of Mombaça were the longest and had greatest total cross-sectional area, and this genotype showed greater proportions of sclerenchyma and vascular tissues than other cultivars and the lowest proportion of mesophyll. The greatest proportion of parenchyma bundle sheaths was also found in Mombaça leaves. Genotypes PM44 and Tanzânia had the lowest proportions of sclerenchyma, and PM44 and BRS Tamani had the lowest proportions of vascular tissues. On the other hand, PM44 and Tanzânia had the greatest proportions of mesophyll. BRS Tamani was comparable with the most used cultivars, Mombaça and Tanzânia, and had forage quality slightly superior to that of Mombaça. Tropical grasses growing under shade can potentially produce less forage but with better nutritive value, in terms of chemical composition and tissue proportions, than grasses grown under full sun. However, as the degree of shading in silvopastoral systems does not occur uniformly across the whole area, the improved nutritive value would not be uniform and may not be very prominent overall.

Tropical beef cattle production involving animals grazing in a shaded and biologically diverse environment, surrounded by high-quality edible biomass, is achievable through silvopastoral systems (SPSs). However, it is necessary to assess the effects of the presence of trees on forage and animal performance over time. In the Brazilian Cerrado, we evaluated the effects of 2 densities of eucalyptus trees in 2 SPSs (8 years of age - SPS22: 227 trees/ha; SPS14: 357 trees/ha) on forage morphology, production and nutritive value of Urochloa brizantha cv. BRS Piatã grass plus performance of Nellore heifers, compared with a grass-only pasture, over a year from 2015 to 2016. On the one hand, SPSs improved (P

The aim of this work was to evaluate the agronomic characteristics, chemical composition and in vitro gas production of sugarcane (Saccharum spp.) cultivars used in ruminant feed. The experimental design was a randomized block containing seven treatments and three replications totaling 21 plots. The cultivars RB835436, RB925211, RB925345, RB937570, RB945961, RB955970 e SP91-1049 was evaluated for dry matter, dry matter yield, stalk percentage, stalk tons per hectare, plant height, stalk diameter, number of tillers per linear meter, mass per stem, soluble solids content (BRIX), NDF/BRIX ratio and tons of sucrose/ha, total digestible nutrients, digestible energy, metabolizable energy, net energy and in vitro digestibility of organic matter, crude protein, neutral detergent fiber (NDF) and acid detergent, of digestion and In vitro gas production of non-fibrous carbohydrates, latency time, digestion rate and gas production of fibrous carbohydrates, and in vitro digestibility of organic matter. There was a significant difference between the cultivars regarding the neutral detergent fiber content, in vitro digestibility of organic matter, total digestible nutrients, digestible energy, net energy, degradation rates of fibrous and non-fibrous carbohydrates and latency period. There was a negative correlation between stem percentage and NDF/BRIX and positive correlation between in vitro digestibility of organic matter and total digestible nutrients. The results were submitted to analysis of variance and mean test by Scott-Knott and Pearson's correlation analysis. The statistical program used was SAEG 2000. The RB835486 variety was superior to the other cultivars, as it presented 93.28% of stem, 57.5% of in vitro digestibility of organic matter, NDF / BRIX ratio of 2.68, 43.78% NDF, latency period 2.86h and fibrous carbohydrate degradation rate of 2.26% per hour. Therefore, this cultivar was better indicated for animal feeding between May and July in the State of Mato Grosso, Brazil.

The objective of this study was to evaluate the behavior of forage sorghum when intercropped with piatã grass and cultivated in eucalyptus sub-forest. The experiment was carried out at the Embrapa Gado de Corte, in Campo Grande - MS. The experimental design was a randomized complete block design with three replications. The main treatments were: monoculture (single sorghum); intercropping (simultaneous sowing of sorghum + piatã grass). The secondary treatments were composed by the sampling sites, with five sites equidistant between the rows of eucalyptus trees (CLFI), with full sun as a control (CLI). The percentage of shading was always higher than 30% in the sub-forest, and the overall average of the system with 63% shade, even after 50% thinning of eucalyptus trees. The intercropping with the grass, an interesting fact, did not affect sorghum grain yield, since it validates the potential of forage sorghum for use in intercropping with perennial grasses, with average grain yield of 2,404.63 kg ha-1. Regarding the sampling sites, it was observed a higher yield in the full sun with 3,283 kg ha-1. The weight of 100 grains was higher for sorghum in monoculture. On the other hand, the upper W1000 was observed at sites A and C. The weight of 1000 grains is considered stable, being affected only under conditions of stress during grain formation. The sorghum intercropped with the piatã grass did not influence the harvest index (HI), while in the shaded environment there was an increase in the harvest index in relation to the full sun. Made available in DSpace on 2020-01-11T00:41:25Z (GMT). No. of bitstreams: 1 SorghumIntercroppedwithPiataGrass.pdf: 226154 bytes, checksum: ed642bb6781e275accc485298dc1ff14 (MD5) Previous issue date: 2019

SUMMARY This study aimed to evaluate the pasture productive and nutritional characteristics of Brachiaria brizantha cv. BRS Piatã in integrated systems with different densities of trees. Considering as plot the systems: integrated crop-livestock-forest with rows of trees (eucalyptus) spaced at 14 m and 357 trees ha-1 (ICLF-14m), ICLF with rows of trees spaced at 22 m and 227 trees ha-1 (ICLF-22m) and the integrated crop-livestock (ICL) with five remaining native trees ha-1; period of the year as subplots, and sampling points as subsubplots (A, B C, D, and E) arranged perpendicular to trees alleys. It was evaluated the production of forage and leaf blade dry mass, leaf:stem ratio, soil coverage, radiation photosynthetically active interception, canopy height, crude protein (CP), neutral detergent fiber (NDF), in vitro digestibility of organic matter (IVDOM) of the leaf blade, and stem associated with the leaf sheath. There was a significant difference (P

One of the challenges for cattle management under extensive grazing systems is understanding how time spent in different individual activities is affected by factors like microclimate and forage quality and availability. The goal of this study is to understand how different tree densities and grazing management can influence the daytime behaviour of Nellore heifers (Bos indicus) kept in silvopastoral systems over a period of 12 months, covering one dry and one rainy season in Central Brazil. Eighty heifers were distributed between three silvopastoral systems with 357, 227 and 5 trees/ha, respectively, each divided into four 1.5 ha paddocks, grazing Piata grass with low (27 ± 4.6 cm) or high (39 ± 5.8 cm) sward heights, and with constant microclimate monitoring. Temperatures recorded were similar between seasons, characterizing an atypical dry period. The use of shade for grazing occurs preferably in the afternoon (72.0 min) and rumination in the morning (47.5 min). The effect of period of the day (P

The aim of the current study is to assess three integrated systems presenting different eucalyptus tree densities due to animal and forage production. The following integrated systems were assessed: crop-livestock-forest with 357 eucalyptus trees ha-1 (ICLF1); crop-livestock-forest with 227 eucalyptus trees ha-1 (ICLF2); and crop-livestock with 5 remnant native trees ha-1 (ICL). The randomized block experimental design was applied in a split-plot scheme with four replicates. The Average Daily Gain (ADG, g animal-1day-1) and the live-weight gain per area (LWG, kg ha-1) were applied to analyze animal performance, which was set by weighing the animals every 28 days (the animals previously fasted for 16h). Forage yield was higher in ICL during fall and winter; in summer, it did not differ from ICLF2. There was no forage yield difference between the ICL and ICLF2 systems in any of the assessed seasons; summer was more productive in ILPF1 than other seasons. The highest leaf crude protein contents (CP) in summer was recorded in systems ICLF1 and ICLF2, and the highest value recorded in fall was found in ILPF1; the lowest was found in ILP. On the other hand, the highest leaf NDF contents in summer were found in ILP. The highest ADG were found in summer. The highest LWG values recorded for the ICL and ICLF2 systems were collected in summer and fall; there was no difference in any of the three systems in winter. The LWG was higher in all system in summer. The ICLF2 emerged as the system (with trees) most appropriate for beef cattle production. Despite the shading interference on forage production, such condition is compensated by the best nutritional contents such as CP. The ICLF2 system allowing an annual LWG of 83% in relation to the ICL system during the fifth year of establishment of the systems.

The objective was to evaluate the animal thermal comfort indices from two integrated crop-livestock-forestry (ICLF) systems. For this, temperature–humidity index (THI), black globe temperature and humidity index (BGHI), and the radiant thermal load (RTL) were assessed. Two ICLF (ICLF-1 and ICLF-2) systems and one control system were established. On the ICLF systems, the arboreal component was the eucalyptus tree (Eucalyptus grandis × Eucalyptus urophylla; H13 clone), planted in simple wide-spaced rows. The ICLF-1 system had a tree spacing of 14 × 2 m with 357 trees per hectare, and the ICLF-2 had a tree spacing of 22 × 2 m with 227 trees per hectare. The control system had five scattered native trees per hectare, pertaining to Gochnatia and Dipteryx species. The forage component in all three systems was piata-grass (Brachiaria brizantha cv. BRS Piata). The experimental design was a randomized block in a sub-subplot design scheme with four replications. The presence of shade provided by the trees offered better conditions of animal comfort when compared with the condition of full sun. The ICLF-1 system, with higher tree density, provided better indicators for thermal comfort, THI, BGHI, and RTL when compared with the condition of full sun, while ICLF-2 was no different than ICLF-1 for BGHI.

Agrosilvopastoral system is a type of production that involves the soil-forage-animal interface, both of which are benefited by the system. Hence, the present study evaluated the effects of agrosilvopastoral system on the quantitative and qualitative characteristics from pasture, and the animal performance during the feeding period of Nellore heifers. The treatments included: Soil-forage-animal – 357 eucalyptus trees per hectare (LFA14x2m); Soil-forage-animal – 227 eucalyptus trees per hectare (LFA22x2m); and Soil-animal – Five native trees remaining per hectare (CON). The forage used was Brachiaria brizantha cv. BRS Piatã and having as trees planted the Eucalyptus urograndis clones H 13. Treatment effects (P 0.05) for average daily gain, while in November period, LFA14x2m treatment showed the lowest value (P 0,05) para la ganancia diaria promedio, mientras que, en noviembre, el tratamiento LFA14x2m tuvo el valor más bajo (P0,05) para ganho médio diário, enquanto no período de novembro, o tratamento LFA14x2m apresentou o menor valor (P

Peltophorum dubium can be an alternative of forestry species to be included in integrated crop-livestock-forestry systems in tropical region. The aim of this research was to evaluate the performance of P. dubium under intraspecific tree competition and cardinal directions to measure the possibility of introduction in integrated livestock-forestry systems. The experiment was performed in a Nelder Wheel competition, which is used in forestry research to test tree competition. The experimental design was factorial (10×2×5) with 12 replicates. The treatments were accomplished by ten tree competitions (159, 201, 255, 322, 408, 516, 653, 827, 1,046 and 1,324 trees ha-1), two cardinal directions (North-South and East-West) and five times after planting (12, 18, 24, 30 and 36 months). The highest tree competition (1,342 trees ha-1) in 36 months after planting, promoted increase in the cylindrical volume of the tree in both North-South and East-West cardinal directions. Nevertheless, the cardinal direction East-West was profitable to increase tree height, diameter at breast height (DBH), cylindrical volume per tree and cylindrical volume per hectare. The DBH measured in 24 months after planting was 5.0 cm, which is considered the minimum DBH to introduce livestock into the integrated system without significant damage on trees. Regarding these preliminary results in the first three years, P. dubium was promising as Brazilian native species to be inserted in integrated livestock-forestry system or single forestry as an option for Eucalyptus spp. Key words: Forestry, dendrometry, Nelder Wheel, integrated systems, agroforestry

Our objective was to evaluate production, nutritive value and carrying capacity of piatã grass (Brachiaria brizantha cv. BRS Piatã), and performance of Nellore heifers in agrosilvopastoral systems (ASPS) with three eucalyptus (Eucalyptus urograndis) tree densities, during winter, spring, summer, and fall. Three integrated systems were evaluated: ASPS-1 (357 trees ha(-1)), ASPS-2 (227 trees ha(-1)), and CON (5 trees ha(-1)). In each system, two sward heights were evaluated: short and tall. A total of 80 11-month-old Nellore heifers were randomly allocated in a randomized split-plot block, 3 × 2 factorial. Greater dry matter availability was observed on CON pastures during the fall season. Greater percentage of leaf lamina was detected on ASPS-1 with short sward height and greater during summer, compared with other seasons. A greater forage production was observed between tree rows and for tall sward height. Spring was the season with less forage nutritive value. Average daily gain was greater during summer and fall. Gain per hectare and stocking rate were greater on CON system and on ASPS-2. Pastures with short sward height had greater gain per hectare and stocking rate. Agrosilvopastoral systems with intermediate tree density seem to be a good choice for producers willing to diversify their revenue sources without decreasing animal production.

Objetivou-se com este estudo avaliar a produtividade e o valor nutritivo das gramíneas forrageiras tropicais: Brachiaria brizantha cvs. Piatã, Xaraés e Marandu, Panicum maximum cv. Mombaça e B. ruziziensis cv. Kennedy, em sistema de integração lavoura-pecuária (ILP), na segunda safra, buscando novas alternativas de produção de forragem para alimentação animal no outono-inverno. Utilizou-se delineamento experimental de blocos ao acaso em esquema de parcelas subsubdivididas, com quatro repetições. Os tratamentos das parcelas corresponderam às cinco forrageiras, às subparcelas corrresponderam a três sistemas de cultivo (monocultivo, consórcio com milho sem supressão e consórcio com milho com supressão), e às sub-subparcelas, quatro intervalos de corte das forrageiras (50, 90, 125 e 195 dias após a emergência, DAE). O experimento foi conduzido no período de fevereiro a setembro de 2014. As produtividades de matéria seca, obtidas aos 195 DAE, referentes aos três sistemas de cultivo (monocultivo, consórcio sem supressão e com supressão), foram de 18,45; 7,15 e 3,05 t ha-1, respectivamente, e os teores de proteína bruta da lâmina foliar das forrageiras decresceram linearmente entre os intervalos de corte, de 50 a 195 DAE, de 19,95 % para 9,70%. O cultivo de forrageiras tropicais em sistemas integrados na segunda safra produz forragem de alta qualidade e quantidade para o outono-inverno. As gramíneas tropicais Panicum maximum cv. Mombaça e Brachiaria brizantha cvs. Xaraés e Piatã apresentaram maior produtividade de folhas e proteína bruta, em comparação às demais forrageiras em estudo. Em termos de valor nutritivo, Brachiaria ruziziensis cv. Kennedy foi superior aos capins Mombaça e Xaraés, porém apresentou menores produtividades de matéria seca total, folha e proteína bruta. De maneira geral, os capins Xaraés, Piatã e Mombaça são os mais indicados para o cultivo na segunda safra em sistema de ILP visando a produção de forragem para alimentação animal.

Três cultivares de Panicum maximum Jacq. submetidas a pastejo rotativo foram avaliadas ao longo do ano quanto aos componentes do comportamento ingestivo (tamanho de bocados, tempo de pastejo e taxa de bocados). Os tratamentos constituíram em: 1) cv. Tanzânia + 50 kg/ha de N, 2) cv. Tanzânia + 100 kg/ha de N, 3) cv. Mombaça + 50 kg/ha de N, e 4) cv. Massai + 50 kg/ha de N. Os valores do tamanho de bocados foram provavelmente superestimados, mas valores abaixo de 0,300 g MS/bocado foram observados, considerado crítico, no período seco. Houve tendência a menores bocados na cv. Massai no período seco, provavelmente em função da distribuição de folhas e material morto ao longo do perfil do relvado. Não houve diferenças no tempo de pastejo entre tratamentos e entre épocas de avaliação, mas o padrão de distribuição do tempo gasto pastejando ao longo do dia modificou nas diferentes épocas. Poucas diferenças nas taxas de bocado foram observadas entre cultivares, e no decorrer do período de ocupação dos piquetes, as taxas de bocado tenderam a aumentar. Entre os componentes do comportamento ingestivo observou-se apenas correlação negativa entre tempo de pastejo e tamanho de bocados (r = –0,45). Three varieties of Panicum maximum Jacq. were evaluated by measuring ingestive behavior components (bite size, grazing time, and rate of eating) for one year under rotational grazing. The treatments were: 1) v. Tanzânia + 50 kg N/ha, 2) v. Tanzânia + 100 kg N/ha, 3) v. Mombaça + 50 kg N/ha, and 4) v. Massai + 50 kg N/ha. The values for bite size were probably overestimated, even so, values lower than 300 g DM/bite size were observed, a critical consideration, in the dry period. There was a tendency for smaller size bites with v. Massai during the dry period, probably due to distribution of leaves and dead material present in the pasture. There were no differences in time of pasturing among treatments and between seasons of evaluation, but the standard of distribution for time spent grazing along with the day was modified by the different seasons. Few differences in rate of eating were observed among the varieties. The rate of eating tended to increase with the length of time in the plots. Among the components of ingestive behavior the only significant correlation observed was between time of pasturing and bite size (r = -0.45).

Foram avaliados o consumo, a composição botânica e o valor nutritivo da dieta de bovinos em pastagens de Brachiaria decumbens e Stylosanthes guianensis cv. Mineirão e de Brachiaria brizantha cv. Marandu e Stylosanthes guianensis cv. Mineirão, submetidas a três taxas de lotação. Adotou-se o delineamento experimental em blocos completos casualizados com os tratamentos no esquema de parcelas subdivididas, com duas repetições. Os tratamentos das parcelas constituíram um fatorial 2x3, sendo duas gramíneas (B. decumbens e B. brizantha cv. Marandu) em consorciação com S. guianensis cv. Mineirão e três taxas de lotação (0,8; 1,2 e 1,6 UA/ha), e as subparcelas, os meses de amostragem (julho e outubro de 1998, correspondendo à época seca; janeiro e abril de 1999, correspondendo à época das águas). Foram utilizados bezerros Nelore, desmamados, com peso vivo médio de 138 kg, no início do experimento. Não foi observado efeito da taxa de lotação sobre as variáveis estudadas. O consumo diário de MS foi maior em pastagens com B. brizantha, em outubro (no final da seca) e em abril (no final das águas), entretanto, dietas de melhor valor nutritivo foram obtidas em pastagens com B. decumbens. As dietas foram constituídas por mais de 80% de folhas de gramínea, enquanto a participação da leguminosa nas dietas foi de apenas 2,1%, com um índice de seleção de 0,08, indicando pouca aceitação deste componente da MS disponível pelos animais em pastejo. The effects of three stocking rates on intake, botanical composition, and nutritive value of the diet of cattle on pastures of Brachiaria decumbens with Stylosanthes guianensis cv. Minerão and B. brizantha cv. Marandu with S. guianensis cv. Mineirão were evaluated. The experimental design was a randomized complete block with two field replications. The treatments were arranged as a 2 x 3 factorial with 2 grasses (B. decumbens and B. brizantha cv. Marandu) in association with S. guianensis cv. Minerão, three stocking rates (0.8, 1.2, and 1.6 AU/ha), and two sampling periods (July and October 1998, corresponding to the early and late dry season; and January and April 1999, corresponding to the mid and late rainy season). Weaned Nellore steers with an average initial weight 138 kg were used. There was no effect of stocking rate on the variables studied. Daily consumption of forage dry matter was higher on pastures with B. brizantha in October (late dry season) and in April (late rainy season). However, it was observed diets with higher nutritive value in B. decumbens pastures. More than 80% of the diet was composed of live grass leaves while legumes represented 2.1% of the diet, with a selection index of 0.08, indicating low contribution of this forage component to the grazing animals.

Avaliou-se o efeito de três taxas de lotação, em pastagens de Brachiaria decumbens x Stylosanthes guianensis cv. Mineirão e de B. brizantha cv. Marandu x S. guianensis cv. Mineirão, sobre a disponibilidade, a composição botânica e o valor nutritivo da forragem. Adotou-se o delineamento experimental em blocos casualizados com os tratamentos no esquema de parcelas subdivididas, com duas repetições. Os tratamentos das parcelas constituíram um fatorial 2x3, sendo duas gramíneas (B. decumbens e B. brizantha cv. Marandu) em consorciação com S. guianensis cv. Mineirão e três taxas de lotação (0,8; 1,2 e 1,6 UA/ha), e as subparcelas, as épocas de amostragem (julho e outubro de 1998, correspondendo à época seca; janeiro e abril de 1999, correspondendo à época das águas). Foram utilizados bezerros Nelore, desmamados, com peso vivo médio de 138 kg, no início do experimento. A disponibilidade de matéria seca (MS) da consorciação B. brizantha x Mineirão não variou entre épocas, com valor médio de 3470 kg/ha de MS, enquanto que, para a consorciação B. decumbens x Mineirão, a média para o período das águas (3485 kg/ha de MS) foi superior a do período seco (3056 kg/ha de MS). A disponibilidade da fração verde da gramínea diminuiu com a elevação da taxa de lotação. Durante a época das águas, verificou-se maior proporção de gramínea, em relação à leguminosa, para uma taxa de lotação estimada de 1,17 UA/ha. As pastagens com B. decumbens apresentaram, de modo geral, maior proporção de forragem verde, de melhor valor nutritivo, associado a maior presença de leguminosa do que as pastagens com B. brizantha. The effect of three stocking rates on intake, botanical composition and the nutritive value of the forage from pastures of Brachiaria decumbens with Stylosanthes guianensis cv. Mineirão and B. brizantha cv. Marandu with S. guianensis cv. Mineirão was evaluated. The experimental design was a randomized complete block with treatments subdivided into plots with two replications. The design of the plots was a 2 x 3 factorial with 2 grasses (B. decumbens and B. brizantha cv. Marandu) in association with S. guianensis cv. Mineirão, three stocking rates (0.8, 1.2, and 1.6 AU/ha), and two sampling periods, corresponding to the dry season (July and October 1998); and to the rainy season (January and April 1999). Weaned Nellore steers with an average initial weight 138 kg were used. The DM availability in the mixed pastures with B. brizantha did not vary between sampling periods and had an average value of 3470 kg DM/ha. However, the pastures with B. decumbens the average for the rainy season (3485 kg DM/ha) was superior to that in the dry season (3056 kg DM/ha). The availability of the green fraction of the grasses was influenced negatively by the increase in stocking rate. During the rainy season, there was a higher proportion of grasses, for an estimated stocking rate of 1.17 AU/ha. B. decumbens pastures maintained a higher proportion of green forage and showed a higher nutritive value associated to a higher presence of legumes than in the B. brizantha pastures.

The influence of cutting age on production and nutritive value of piata grass (Brachiaria brizantha cv. BRS Piata) and hybrid sorghum (Sorghum spp. cv. BRS 801) under an integrated crop- livestock system was evaluated. The trial was carried out at the Embrapa Beef Cattle (2027 S; 5437 W) in Campo Grande, Mato Grosso do Sul State, Brazil, between April and October 2009. Experimental design consisted of randomized blocks with four replicates. Treatments were distributed across a split-plot design, which included three production systems (single piata grass; single hybrid sorghum; mixed cultivation of sorghum and piata grass). Half-plots consisted of three forage ages at harvest (with 70, 90 and 110 days after seeding). Variables included agronomical characteristics, productivity and nutrition value. Regardless of the evaluated systems, cutting age affected agronomical characteristics and in vitro digestibility of organic matter (IVDOM). Production was highest (4,048 kg ha -1 ) within the integrated system. Regardless of cutting age, monoculture sorghum had the highest crude protein level. Results showed that integrated sorghum and piata grasses were an asset for forage productivity. Forages had higher values in crude protein and in in vitro digestibility of organic matter on the 70 th day after seeding.

O experimento foi conduzido em Cáceres, Estado do Mato Grosso, com o objetivo de avaliar o efeito de doses de nitrogênio sobre a produção de forragem e a composição química do capim-tifton 85 (Cynodon spp.). Utilizou-se o delineamento em blocos completos casualizados com cinco tratamentos (0, 60, 120, 180 e 240 kg ha-1 de N) e quatro repetições, em parcelas de 4,0 x 5,0 m. Foram realizados quatro cortes a intervalos de 30 dias, na altura de 5 cm do nível do solo, sendo as doses de N parceladas em quatro aplicações após cada corte, sob a forma de ureia, em cobertura. Foi observado, para cada kg ha-1 de N aplicado, aumento, na produção de matéria seca total de 22,67 kg ha-1, na produção de lâmina foliar verde de 11,37 kg ha-1, na altura do relvado de 0,052 cm e no teor de proteína bruta da forragem de 0,00955 dag kg-1, e diminuição no teor de FDN de 0,0142 dag kg-1. Observou-se aumento na extração de N a uma taxa de 0,537 kg kg-1 de N e diminuição acentuada da eficiência de utilização do N a partir da dose estimada de 155 kg ha-1 de N. The experiment was carried out in Cáceres, Mato Grosso State, Brazil, aiming to evaluate the effect of nitrogen (N) on forage production and chemical composition of Tifton 85 bermudagrass (Cynodon spp.). A randomized complete block design was used, with five treatments (0, 60, 120, 180 and 240 kg ha-1) and four replications in 4.0 x 5.0 m plots. Four cuts were made at intervals of 30 days, at the height of 5 cm above ground level. N was applied after each cut, in the form of urea. For each kg ha-1 of N applied, we observed increases of 22.67 kg ha-1 in the production of total dry mass, 11.37 kg ha-1 in the production of green leaf blade, 0.052 cm in sward height, and 0.00955 dag kg-1 in crude protein content, and a reduction of 0.0142 dag kg-1 in NDF content. There was an increase in the extraction of N at a rate of 0.537 kg kg-1 of N, and sharp decline in the efficiency of N utilization from the estimated dose of 155 kg ha-1 of N.

Três cultivares de Panicum maximum Jacq. submetidos a pastejo rotativo foram avaliados ao longo do ano, antes e após o período de pastejo, quanto à composição botânica e química da dieta, consumo de matéria seca e ganho de peso animal. Os tratamentos constituíram em: 1) cv. Tanzânia + 50 kg/ha de N, 2) cv. Tanzânia + 100 kg/ha de N, 3) cv. Mombaça + 50 kg/ha de N, e 4) cv. Massai + 50 kg/ha de N. As dietas selecionadas pelos animais na cv. Massai tenderam a apresentar os menores valores de digestibilidade e proteína bruta e os maiores de fibra em detergente neutro, enquanto na cv. Mombaça as dietas continham, em geral, maiores teores de sílica. Os animais selecionaram, em média, 92,4% de folhas verdes, independentemente do tratamento e da época de amostragem. Os animais consumiram semelhantes quantidades de forragem nos diversos tratamentos, apresentando, em média, consumos de 1,9; 2,8; 3,4; e 2,3 kgMS/100kgPV, respectivamente, em junho, setembro e novembro de 1998 e março de 1999. Os piores resultados quanto ao ganho de peso por animal foram verificados na cv. Massai, mas, devido a sua alta capacidade de suporte na época chuvosa, superou a cv. Mombaça e cv. Tanzânia + 50 kg/ha de N, em termos de ganho de peso por área. A participação de folhas, a altura do pasto, o teor de proteína bruta da dieta selecionada pelos animais e o tamanho de bocado foram os fatores que mais influenciaram positivamente o ganho de peso animal. Three varieties of Panicum maximum Jacq. were evaluated by measuring the botanical and chemical composition of the diet, and the dry matter intake and weight gain of the animal under rotational grazing, before and after a period of grazing. The treatments were: 1) v. Tanzânia + 50 kg N/ha, 2) v. Tanzânia + 100 kg N/ha, 3) v. Mombaça + 50 kg N/ha, and 4) v. Massai + 50 kg N/ha. Of the diets selected by the animals, v. Massai tended to show lower values for digestibility and crude protein, and higher values for neutral detergent fiber; however, in general, the diets containing v. Mombaça had higher values for silica. The animals selected an average of 92.4% green leaves, independent of treatment and season of sampling. The animals consumed similar quantities of forage on the diverse treatments, with average intakes of 1.9, 2.8, 3.4, and 2.3 kg DM/100 kg BW, respectively, for June, September and November of 1998 and March of 1999. Low weight gains of the animals on v. Massai were verified, but due to the higher availability of forage during the rainy season, the weight gains per hectare were higher than for v. Mombaça + 50 kg N/ha and v. Tanzânia+ 50 kg N/ha. Factors which had the most positive influence on weight gain of the animals were quantity of leaves, height of the pasture, crude protein content of the diet selected by the animals, and size of the bite.

Três cultivares de Panicum maximum Jacq. submetidos a pastejo rotativo foram avaliados ao longo do ano, antes e após o período de pastejo, quanto às disponibilidades de matéria seca total e de folhas, altura, profundidade pastejada, densidade, participações de folhas, colmos e material morto, relações folha/colmo e folha/material morto. Os tratamentos constituíram em: 1) cv. Tanzânia + 50 kg/ha de N, 2) cv. Tanzânia + 100 kg/ha de N, 3) cv. Mombaça + 50 kg/ha de B e 4) cv. Massai + N 50 kg/ha de N. O cultivar Mombaça apresentou menores disponibilidades de folhas, e maiores proporções de colmo, enquanto o cv. Massai tanto apresentou características que poderiam favorecer a seleção de folhas, como maior densidade de MS e maior relação folha/colmo, como a característica desfavorável de apresentar menor relação folha/material morto. No cv. Tanzânia, a adubação nitrogenada no final do período chuvoso trouxe benefícios apenas em março, quando houve aumento nas relações folha/colmo e folha/material morto. A profundidade pastejada correlacionou-se positivamente com a altura, e os animais pastejaram em média 41% da altura da pastagem, no período seco, e 47% no período chuvoso. Three cultivars of Panicum maximum Jacq. under rotational grazing were evaluated for one year, before and after grazing, when measurements were made of the availability of total dry matter, height, residual dry matter, forage density, leaf dry matter, participation of leaves, stems and dead material, and ratios of leaf:stem and leaf:dead plant material. The treatments were 1) v. Tanzania + 50 kg N/ha, 2) v. Tanzania + 100 kg N/ha, 3) v. Mombaça + 50 kg N/ha, and 4) v. Massai + 50 kg N/ha. The Mombaça cultivar presented the poorest results, lowest production of leaves and the highest proportion of stems. However, the cv. Massai deservers attention for characteristics such as higher density of DM and higher leaf lamina:stem ratio; however, it presented a lower ratio of leaves:dead material. There were no significant differences in percentage of leaves among the cultivars. In the cv. Tanzania, nitrogen fertilization at the end of the rainy period had beneficial effects only in March when there was an increase in the leaf:stem and leaf:dead plant material ratios. The residual dry matter correlated positively with the height of the forage. The animals grazed 41% of the height of the pasture in the dry period, and 47% in the rainy period.

O estudo foi conduzido com o objetivo de estimar o valor nutritivo da MS de três cultivares de Panicum maximum Jacq. submetidas ao pastejo rotativo, através dos teores de proteína bruta, fibra em detergente neutro, fibra em detergente ácido, lignina, celulose, sílica e digestibilidade in vitro da matéria orgânica em amostras de folhas e colmos. Estudou-se, também, no cultivar Tanzânia, a adubação nitrogenada no final do período chuvoso, adicional à de manutenção comum às demais cultivares. As amostragens foram realizadas em junho, setembro e novembro de 1998 e março de 1999. Algumas diferenças entre tratamentos foram observadas, apresentando, em geral, menor valor nutritivo no cv. Massai, com menores teores de proteína bruta e digestibilidade e maiores teores de fibra em detergente neutro, fibra em detergente ácido e lignina tanto nas folhas, como nos colmos. Sua utilização como opção forrageira deve basear-se em outras características agronômicas. O cv. Mombaça apresentou, em geral, maiores teores de sílica e seu valor nutritivo não foi afetado pela adubação nitrogenada no final do período chuvoso, exceto pelo aumento no teor de proteína bruta e pela redução do conteúdo de lignina e sílica em março. O valor nutritivo dos colmos foi inferior ao das folhas. O início do período chuvoso foi, em geral, a época de maior valor nutritivo da forragem em todos os tratamentos. A study was conducted to evaluate three cultivars of Panicum maximum Jacq. under rotational grazing for the nutritive value,where the estimates of crude protein, neutral detergent fiber, acid detergent fiber, lignin, cellulose, silica, and in vitro digestibility of the organic material were performed in samples of leaves and stems. Additional nitrogen was applied in cv. Tanzania at the end of the rainny season. Samples were taken in June, September, and October 1998 and in March 1999. Some differences among treatments were observed. In general, cv. Massai showed a lower nutritive value with lower crude protein and digestibility, and higher neutral detergent fiber, acid detergent fiber, and lignin, either in samples of leaves or in stems. Therefore, its utilization as a forage option should be based on other agronomic characteristics. The cv. Mombaça exhibited higher concentrations of silica and its nutritive value was not affected by nitrogen fertilization at the end of the rainny season, except for an increase in the percentage of crude protein and a reduction in the amount of lignin and silica in March. The nutritive value of the stems was inferior to the leaves. The nutritive value was highest in all treatments at the beginning of the rainny period.

Avaliou-se o efeito de três taxas de lotação (0,8; 1,2; e 1,6 UA/ha), em pastagens de Brachiaria decumbens x Stylosanthes guianensis cv. Mineirão e de B. brizantha cv. Marandu x S. guianensis cv. Mineirão, no Cerrado, sobre a produção por animal e por área, visando sugerir o manejo mais adequado. Adotou-se o delineamento experimental em blocos casualizados com os tratamentos no esquema de parcelas subdivididas, com duas repetições. Os tratamentos das parcelas constituíram um fatorial 2x3, sendo duas gramíneas (B. decumbens e B. brizantha cv. Marandu) em consorciação com S. guianensis cv. Mineirão e três taxas de lotação (0,8; 1,2 e 1,6 UA/ha), e as subparcelas, as épocas do ano. Foram utilizados bezerros Nelore, desmamados, com peso vivo médio de 138 kg, no início do experimento. O ganho de peso vivo médio diário (GPD) dos animais foi influenciado pela gramínea, pela época do ano e pela taxa de lotação. As pastagens com B. decumbens proporcionaram maior GPD que as pastagens com B. brizantha (409 x 333 g/novilho.dia). Na época das águas, foi observado maior GPD do que na seca, 490 e 194 g/novilho.dia, respectivamente. Houve decréscimo linear do GPD com o aumento da taxa de lotação, estimando-se valores de 435; 371 e 308 g/novilho.dia para as taxas de 0,8, 1,2 e 1,6 UA/ha, respectivamente. Houve influência da gramínea e da época do ano sobre o ganho de peso por área. As pastagens com B. decumbens proporcionaram maior produção por área do que as com B. brizantha, com ganhos de peso vivo de 464 e 352 kg/ha.ano, respectivamente. Durante a época das águas, a produção por área foi maior que na seca, com valores médios de 331 e 77 kg/ha.ano, respectivamente. Não houve influência da taxa de lotação sobre a produção por área, entretanto, observou-se resposta com tendência curvelinear, indicando que a taxa de lotação mais adequada estaria entre 1,25 e 1,30 UA/ha. Mixed pastures of Brachiaria decumbens with Stylosanthes guianensis cv. Mineirão and B. brizantha cv. Marandu with S. guianensis cv. Mineirão, under three stocking rates (0.8, 1.2 and 1.6 AU/ha) were evaluated in regard to the animal daily gain and liveweight gain per ha, in the Brazilian Savanna, in order to suggest the most adequate management. A randomized block in a split-plot design with two replicates was used. The plots treatments were constituted of a 2x3 factorial, two grasses (Brachiaria decumbens and B. brizantha cv. Marandu) associated with Stylosanthes guianensis cv. Mineirão and three stocking rates (0.8, 1.2 and 1.6 AU/ha), and the split-plot as year seasons. Weaned Nellore steers (average initial weight of 138 kg), in the beginning of the experiment, were used. The grass, season and stocking rate affected the daily average weight gain. Animals grazing B. decumbens showed higher DWG than those grazing B. brizantha (409 x 333 g/head.day). It was observed higher DWG in the rainy season in relation to the dry season (490 and 194 g/head.day). DWG decreased linearly as stocking rate increased, and values of 435, 371 and 308 g/head.day were estimated for stocking rates of 0.8, 1.2 and 1.6 AU/ha, respectively. Animals grazing B. decumbens showed higher production per ha than those grazing B. brizantha, with liveweight gains of 464 and 352 kg/ha.year, respectively. Weight gain per ha was affected by grass and year season. The production per ha was higher in the rainy season than in the dry one, with average values of 331 and 77 kg/ha.year, respectively. The stocking rate did not affect production per ha, however, there was curvilinear tendency, indicating that the most adequate stocking rate ranged from 1.25 to 1.30 UA/ha.

The objective was to evaluate animal performance and nutritional characteristics of Brachiaria brizantha cv. BRS Piatã in two integrated systems, during the summer and winter, five years after the initial establishment of the area. The randomized block experimental design was adopted with treatments consisting of a control (five native trees per hectare) and an integrated crop-livestock-forestry (ICLF) system with 227 eucalyptus trees per hectare. Animal performance, canopy height, soil cover, forage mass (leaf, stem and senescent material), and forage nutritive value were evaluated. Differences between systems were observed in forage mass (total, leaf, stem and senescent material), soil cover and forage nutritive value in both seasons. Shading conditions provided by eucalyptus in the ICLF system lead to a reduction in forage mass and neutral detergent fiber content, and to an increase in crude protein and in vitro organic matter digestibility. However, no effect on animal performance was obtained. The presence of trees improves the forage nutritive value without impacting animal performance in integrated systems. RESUMO O objetivo foi avaliar o desempenho animal e as características nutricionais de Brachiaria brizantha cv. BRS Piatã em dois sistemas integrados, durante o verão e o inverno, cinco anos após o estabelecimento inicial da área. O delineamento experimental em blocos ao acaso foi adotado com tratamentos constituídos por um controle (cinco árvores nativas por hectare) e um sistema integrado lavoura-pecuária-floresta (ILPF) com 227 eucaliptos por hectare. Desempenho animal, altura do dossel, cobertura do solo, massa de forragem (folha, caule e material senescente) e valor nutritivo da forragem foram avaliados. Diferenças entre os sistemas foram observadas na massa de forragem (total, foliar, caule e material senescente), na cobertura do solo e no valor nutritivo da forragem em ambas as estações. As condições de sombreamento proporcionadas pelo eucalipto no sistema ICLF levaram a uma redução na massa de forragem e no teor de fibra em detergente neutro e a um aumento na proteína bruta e na digestibilidade in vitro da matéria orgânica. No entanto, nenhum efeito no desempenho animal foi obtido. A presença de árvores melhora o valor nutritivo da forragem, sem impactar o desempenho animal em sistemas integrados.

This research aimed to evaluate the maize grain yield and forage of grass species under intercropping system using nicosulfuron herbicide. In order to assess the parameters related to maize, a randomized block design was defined. The treatments were arranged in a (5 × 2+ 1) × 2 factorial design with four repetitions resulting in 11 treatments, where maize was cultivated under intercropping condition with different forage species (5) (Brachiaria brizantha cv. Marandu, Piatã, Xaraés, Brachiaria ruziziensis and Panicum maximum cv. Mombaça) and maize monoculture (1) as control treatment, with and without nicosulfuron herbicide application (2) in two growing seasons (2014 and 2015). The off-season intercropping of maize with tropical forage grasses with and without herbicide suppression decreased maize grain yield. The suppression with nicosulfuron herbicide decreased the dry matter production of forage grasses. Intercropping of P. maximum cv. Mombaça with maize showed higher decrease in maize grain yield. On the other hand, it showed higher forage grasses production for livestock feeding. B. brizantha cv. Piatã was the forage which less affected maize grain yield under intercropping, even with absence of nicosulfuron suppression. Off-season maize under intercropping with tropical forages can be used to recover degraded pastures; increasing forage dry matter production for livestock, remaining the soil covered with straws with possibility of no-till seeding for the next cultivation. Made available in DSpace on 2020-01-08T00:41:34Z (GMT). No. of bitstreams: 1 Yieldofmaizeandtropicalgrasses.pdf: 843647 bytes, checksum: 24ca13307d4e4a10b151acead737defd (MD5) Previous issue date: 2019