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Search Results: 1 - 10 of 26486 matches for " Ribeiro Karina Guimar?es "
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Produtividade de matéria seca e composi??o mineral do capim-tifton 85 sob diferentes doses de nitrogênio e idades de rebrota??o
Ribeiro, Karina Guimares;Pereira, Odilon Gomes;
Ciência e Agrotecnologia , 2011, DOI: 10.1590/S1413-70542011000400022
Abstract: the dry matter production and mineral content of tifton 85 bermudagrass (cynodon nlemfüensis x cynodon dactylon) on nitrogen rates (0, 100, 200, 300 and 400 kg/ha) and regrowth ages (28, 42 and 56 days) were evaluated. the experimental design was completely randomized with a split plot feature. the main plots referred to n-rates whereas subplots were regrowth ages. the forage yield ranged from 5.75 to 20.46, from 8.13 to 22.85 and from 10.52 and 25.23 t/ha of dm, in response to rates of 0 to 400 kg n/ha, in plants harvested at 28, 42 and 56 days of regrowth, respectively, with a response efficiency of 36.8 kg dm/kg n. the p contents decreased with n rates and plant age increased ranged from 0.27 to 0.16%. the k contents decreased as plant age increased; the maximum k content of 1.25, 1.11, and 0.96% were recorded for plant harvest with 28, 42 and 56 days of regrowth, respectively, fertilized with 55 kg n/ha/cutting. the average ca content was 0.48%. the mg content increased as n rates increased and decreased as plant age increased, with values between 0.24 and 0.45%.
Aduba??o nitrogenada do capim-elefante cv. Mott: 2. valor nutritivo ao atingir 80 e 120 cm de altura
Ribeiro, Karina Guimares;Gomide, José Alberto;Paciullo, Domingos Sávio Campos;
Revista Brasileira de Zootecnia , 1999, DOI: 10.1590/S1516-35981999000600004
Abstract: this trial was carried out, from october 1993 until june 1995, to evaluate the chemical composition and dry matter digestibility of dwarf elephantgrass at plant heights of 80 and 120 cm under five nitrogen rates. the experimental design was completely randomized with a split split plot arrangement, with four replicates, where the clipping factors, and nitrogen doses (0, 25, 50, 100kg/ha?clipping, in the first year, and 0, 75 and 100 kg ha?clipping, in the second year, and plant heights (80 and 120 cm) and its effects on the grass performance to yield were studied. the crude protein content in the leaf blades ranged, in the first year, from 8.8 to 13.2, in plants that reached 80 cm, and from 9.7 to 11,3% in plants with 120 cm, and in average, from 9.6 to 12.6%, in the second year, in response to the doses of nitrogen. the neutral detergent fiber, that was of 71.7% in the first year, varied from 67.4 to 71.1%, in plants with 80 and 120 cm, respectively, in the second year. the observed coefficients of ivdmd were 66.3 and 64.9% for plant heights of 80 and 120 cm, in the first year, and 69.0 and 61.5, in the second year, in the leaf blades of plants with 80 and 120 cm, respectively. the p, k and ca contents in the leaf blade inversely varied with the nitrogen doses, while the mg content did not present variation.
Eficiência microbiana, fluxo de compostos nitrogenados no abomaso, am nia e pH ruminais, em bovinos recebendo dietas contendo feno de capim-tifton 85 de diferentes idades de rebrota
Ribeiro Karina Guimares,Garcia Rasmo,Pereira Odilon Gomes,Valadares Filho Sebasti?o de Campos
Revista Brasileira de Zootecnia , 2001,
Abstract: Avaliaram-se a eficiência de síntese microbiana, o fluxo de compostos nitrogenados no abomaso, o balan o de compostos nitrogenados, a taxa de passagem da digesta ruminal, a concentra o de am nia e o pH ruminais, em bovinos recebendo ra es contendo feno de capim-tifton 85 de diferentes idades de rebrota. Utilizaram-se quatro animais zebu, com peso médio de 340 kg, fistulados no rúmen e abomaso, distribuídos em um delineamento em quadrado latino 4 x 4. Todas as ra es continham 60% de volumoso e 40% de concentrado. O volumoso foi constituído de feno de capim-tifton 85 de 28, 35, 42 e 56 dias de idade e o concentrado continha fubá de milho e mistura mineral. Os microorganismos ruminais foram quantificados utilizando-se as bases purinas como indicador. O pH e N-amoniacal foram mensurados, no fluido ruminal, antes e 2; 4 e 6 horas após o fornecimento da ra o. A taxa de passagem foi determinada pelo modelo unicompartimental, utilizando-se o óxido cr mico como indicador. As eficiências de síntese microbiana n o foram influenciadas pela idade do feno na ra o, apresentando valores médios de 31,32 g Nbact/kg MODR; 30,74 g Nbact/kg CHODR; 337,4 g MSbact/kg CHODR; e 12,5 g PBbact/100 g NDT. Estimaram-se máximos fluxos de compostos nitrogenados totais, amoniacais e n o-amoniacais, de 119,0; 9,76; e 109,6 g/dia, com a inclus o de feno com 39,7; 37,6; e 39,9 dias de idade, respectivamente, e fluxo de compostos nitrogenados bacterianos de 80,54 g/dia, em média. O balan o de nitrogênio, a taxa de passagem, as concentra es de am nia e o pH ruminais também n o foram influenciados pela idade do feno na ra o, encontrando-se valores de 30,67 g/dia; 3,2%/h; 9,7 mg/100mL (máximo às 1,38h) e 6,08 (mínimo às 6,64h), respectivamente.
Caracteriza o das fra es que constituem as proteínas e os carboidratos, e respectivas taxas de digest o, do feno de capim-tifton 85 de diferentes idades de rebrota
Ribeiro Karina Guimares,Pereira Odilon Gomes,Valadares Filho Sebasti?o de Campos,Garcia Rasmo
Revista Brasileira de Zootecnia , 2001,
Abstract: Avaliaram-se a composi o bromatológica, as fra es da proteína bruta (A, B1, B2, B3 e C) e dos carboidratos totais (A, B1, B2 e C) e as respectivas taxas de digest o das fra es B1, B2 e B3 de proteínas e das fra es A + B1 e B2 de carboidratos e do feno de capim-tifton 85, obtido de plantas colhidas com 28, 35, 42 e 56 dias de rebrota, adubadas com 75 kg/ha/corte de N. Os teores protéicos dos fenos com idades de rebrota de 28 a 56 dias variaram de 17,58 a 12,58%. Os valores das fra es protéicas A, B1, B2, B3 e C apresentaram-se, respectivamente, entre 22,10 e 35,53%; 0,24 e 4,55%; 30,37 e 31,34%; 26,55 e 36,62%; e 5,75 e 6,76%, como propor es da proteína bruta total, nos fenos com idades de rebrota entre 28 e 56 dias. As taxas de digest o das fra es protéicas B1, B2 e B3 encontraram-se entre 0,319 e 1,324; 0,0724 e 0,0936; e 0,0077 e 0,012 h -1, respectivamente, nos fenos com idades de rebrota entre 28 e 56 dias. Os teores de carboidratos totais variaram de 72,98 a 78,77%, em fenos com 28 a 56 dias de rebrota. Os valores das fra es A, B1, B2 e C de carboidratos apresentaram-se entre 2,73 e 5,44%; 1,91 e 2,35%; 77,49 e 80,59%; e 13,59 e 17,87%, respectivamente, como propor es dos carboidratos totais, em fenos com idades entre 28 e 56 dias de rebrota. As taxas de digest o das fra es de carboidratos A + B1 e B2 encontraram-se entre 0,181 e 0,20 e 0,04 e 0,0466 h -1, respectivamente, em fenos com idades entre 28 e 56 dias de rebrota.
Consumo e digestibilidades aparentes total e parcial, de nutrientes, em bovinos recebendo ra es contendo feno de capim-Tifton 85 de diferentes idades de rebrota
Ribeiro Karina Guimares,Garcia Rasmo,Pereira Odilon Gomes,Valadares Filho Sebasti?o de Campos
Revista Brasileira de Zootecnia , 2001,
Abstract: Avaliaram-se o consumo, a digestibilidade aparente total e as digestibilidades aparentes ruminal e intestinal de ra es contendo feno de capim-tifton 85 (Cynodon spp.) de diferentes idades de rebrota, em bovinos. Utilizaram-se quatro animais, fistulados no rúmen e abomaso, distribuídos em quadrado latino 4 x 4. Todas as ra es continham 60% de volumoso e 40% de concentrado. O volumoso era constituído de feno de capim-tifton 85 de 28, 35, 42 e 56 dias de rebrota, e o concentrado continha somente fubá de milho e mistura mineral. Os consumos de matéria seca (MS), matéria organica (MO), proteína bruta (PB), fibra em detergente neutro (FDN), carboidratos totais (CHOS), nutrientes digestíveis totais (NDT), matéria organica digestível (MOD) e carboidratos digestíveis totais (CHOSD) foram influenciados pela idade do feno na ra o, com valores máximos estimados em 5,81; 5,51; 0,71; 3,4; 4,69; 4,17; 4,04; e 3,5 kg/dia, respectivamente, às idades de 40,6; 40,6; 32,6; 41,5; 42,2; 37,6; 37,7; e 39 dias. As digestibilidades aparentes totais da FDN e dos CHOS totais reduziram-se 0,33 e 0,21 unidades percentuais, para cada dia de avan o na idade do feno na ra o, variando de 68,5 a 59,1% e de 76,9 a 71,1%, respectivamente. As digestibilidades aparentes totais da MS, MO, PB e EE n o foram influenciadas pela idade do feno na ra o, apresentando valores médios de 70,9; 72,6; 60,0; e 74,4%, respectivamente. As digestibilidades aparentes ruminal e intestinal dos nutrientes também n o foram influenciadas pela idade do feno na ra o.
Produtividade e composi o bromatológica de Brachiaria spp., no Alto Vale do Jequitinhonha Productivity and bromatological composition of Brachiaria spp. in the Higher Jequitinhonha Valley
Rosana Cristina Pereira,Karina Guimares Ribeiro,Odilon Gomes Pereira,Janaina de Lima Silva
Ciência e Agrotecnologia , 2011,
Abstract: Avaliaram-se a produtividade de matéria seca (MS), propor o de laminas e composi o bromatológica de Brachiaria spp., colhidas com 42 dias de rebrota o, em Diamantina, MG. Para a determina o dos teores de MS, PB, FDN, FDA e lignina utilizaram-se o esquema em parcelas subsubdivididas, no DIC, com quatro repeti es. Nas parcelas foram distribuídas as cultivares Basilisk, Marandu, Xaraés, Llanero e B. humidicola comum; nas subparcelas, dois cortes, e, nas subsubparcelas, dois anos experimentais. A produ o de MS total e a propor o de laminas foram analisadas em esquema de parcelas subdivididas, com espécies/cultivares nas parcelas e anos nas subparcelas. A produ o de MS no segundo ano (3 cortes) foi mais alta que no primeiro (2 cortes), destacando-se as cultivares Basilisk, Xaraés e Llanero. De modo geral, as cultivares apresentaram teores satisfatórios de PB, mais altos no segundo ano. Os teores de FDN foram mais baixos no segundo ano e os de lignina mais baixos no primeiro ano. As cultivares Xaraés e Marandu destacam-se pela elevada propor o de folhas e apresentam composi o bromatológica semelhante a da cultivar Basilisk. Associando-se a composi o bromatológica com a produtividade de MS, recomendam-se as cultivares Xaraés e Basilisk para as condi es do Alto Vale do Jequitinhonha. Dry matter production, proportion of leaf blades and chemical composition of Brachiaria spp. harvested at intervals of 42 days of regrowth, in Diamantina, MG were evaluated. The DM, CP, NDF, ADF and lignin contents were analyzed in a split-split plot completely randomized design, with four replicates. Five cultivars of Brachiaria were distributed in the plots, two cuts in the split-plot, and two experimental years in the split-split plot. The dry matter production and the proportion of leaf blades were analyzed in a split plot completely randomized design, with cultivars in the plots and years in the subplots. The dry matter production in the second year (3 cuts) was higher than in the first (2 cuts), especially with the cultivars Basilisk, Xaraés and Llanero. Generally, the cultivars presented satisfactory levels of CP, with higher values in the second year. The contents of NDF were lower in the second year and the lowest levels of lignin were in the first year. Cultivars Xaraés and Marandu stand out for the high proportion of leaves and presented chemical composition similar to the Basilisk cultivar. Based on the chemical composition and dry matter production, Xaraés and Basilisk cultivars are recommended for cultivation in the Jequitinhonha High Valley.
Crescimento do capim-tifton 85 sob doses de nitrogênio e alturas de corte
Pereira, Odilon Gomes;Rovetta, Rivelino;Ribeiro, Karina Guimares;Santos, Manoel Eduardo Rozalino;Fonseca, Dilermando Miranda da;Cecon, Paulo Roberto;
Revista Brasileira de Zootecnia , 2012, DOI: 10.1590/S1516-35982012000100005
Abstract: the objective this study was to evaluate the growth rates of tifton 85 bermudagrass under four nitrogen levels (0, 33, 66, 100, and 133 kg/ha n) and harvested at three plant heights (30, 40 and 50 cm). the experimental design was completely randomized in a split plot scheme with three replications. nitrogen rates were set in the plots and plants heights in the subplots. for all variables, the interaction n rate × plant height was not significant. the net assimilatory rate and relative growth rate of tifton 85 increased with increasing n rates. the leaf area ratio (lar) decreased linearly with plant height at harvesting. in contrast, the lar increased linearly with n rate. linearly, the leaf weight ratio decreased with plant height at harvesting, and increased with n rate. the specific leaf area of tifton 85 bermudagrass was influenced linear and positively only by nitrogen fertilization. the leaf area index (lai) of tifton 85 bermudagrass increased by about 0.05 unit for each centimeter increase in plant height at harvesting. there was a quadratic response of n in lai of tifton 85 bermudagrass. the increase of bermudagrass height at harvesting season decreases the participation of leaf blade in the forage. the nitrogen increases the growth rate of tifton 85 bermudagrass. to ensure efficient harvesting of forage, the increase of n rate for tifton 85 bermudagrass implies a reduction in the harvest interval.
Eficiência microbiana, fluxo de compostos nitrogenados no abomaso, am?nia e pH ruminais, em bovinos recebendo dietas contendo feno de capim-tifton 85 de diferentes idades de rebrota
Ribeiro, Karina Guimares;Garcia, Rasmo;Pereira, Odilon Gomes;Valadares Filho, Sebasti?o de Campos;Cecon, Paulo Roberto;
Revista Brasileira de Zootecnia , 2001, DOI: 10.1590/S1516-35982001000200038
Abstract: the microbial efficiency synthesis, the abomasum nitrogen compounds flow, the nitrogen compounds balance, the passage rate of ruminal digest, the ruminal ammonia concentration and ruminal ph in cattle fed diets containing tifton 85 bermudagrass hay with different regrowth ages were evaluated. four rumen and abomasum fistulated zebu cattle with average 340 kg lw were allotted in a 4x4 latin square. all diets contained 60:40 forage to concentrate ratio. the forage was consisted in tifton 85 bermudagrass hay with 28, 35, 42 and 56 days of age, and the concentrate contained corn meal and mineral mix. the amount of microorganisms was determined using purines as a marker. the ph and n-ammonia were determined in the ruminal fluid before and 2, 4 and 6 hours after feeding. the passage rate was determined by unicompartimental model using the chromic oxide as a marker. the microbial efficiency synthesis was not affected by the age of the hay in the diet, presenting mean values of 31.32 g nbact/kg rdom, 30.74 g nbact/kg rdcho, 33.74 g dmbact/kg rdcho and 12.5 g cpbact/100 g tdn. the maximum estimates of total nitrogen compound flows, ammonia and non ammonia were 119.0, 9.76 and 109.6 g/day, with the inclusion of hay with 39.7; 37.6 and 39.9 days of regrowth age, respectively and the bacterial nitrogen compounds flow of 80.54 an average. nitrogen balance, passage rate, ruminal ammonia concentration and ruminal ph also were not affected by the age of the hay, with values of 30.67 g/day, 3.2%/h, 9.7 mg/100ml (maximum at 1.38h) and 6.08 (minimum at 6.64 h), respectively.
Características morfogênicas e estruturais do capim-tifton 85 sob doses de nitrogênio e alturas de corte
Pereira, Odilon Gomes;Rovetta, Rivelino;Ribeiro, Karina Guimares;Santos, Manoel Eduardo Rozalino;Fonseca, Dilermando Miranda da;Cecon, Paulo Roberto;
Revista Brasileira de Zootecnia , 2011, DOI: 10.1590/S1516-35982011000900005
Abstract: the objective of this study was to evaluate the morphogenic and structural characteristics of tifton 85 bermudagrass under different nitrogen doses (0, 33, 66, 100 or 133 kg/ha.year of n) and three different plant heights (30, 40 or 50 cm) at harvesting time. a split plot scheme in a completely randomized design with three replications was used. the nitrogen (n) doses stood for the portions and the haversting heights, for the subportions. the leaf appearance rate of tifton 85 bermudagrass was negatively influenced by plant height at harvesting time, but positively influenced by n dose. leaf senescence rate and total number of leaves per tiller decreased, whereas leaf elongation rate increased with nitrogen fertilization. on the other hand, leaf senescence rates and total leaf number per tiller increased according to the plant height at harvesting time. contrarily, the number of green leaf per tiller was not influenced by n dose or plant height at harvesting time. for the same height of 'tifton 85' bermudagrass at harvesting time, nitrogen fertilization increases tissues flux and defoliation frequency. under intermittent defoliation conditions, 'tifton 85' bermudagrass should be harvested at 30 cm of height.
Níveis de proteína bruta em dietas para bovinos de corte: consumo, digestibilidade total e desempenho produtivo
Cavalcante, Maria Andréa Borges;Pereira, Odilon Gomes;Valadares Filho, Sebasti?o de Campos;Ribeiro, Karina Guimares;
Revista Brasileira de Zootecnia , 2005, DOI: 10.1590/S1516-35982005000300001
Abstract: the intake and total apparent digestibility of dry matter (dm), organic matter (om), crude protein (cp), ether extract (ee), neutral detergent fiber (ndf) and nonfiber carbohydrate (nfc) with and without correction for ashes and crude protein, the weight gain, carcass yield and the food conversion were estimated in beef cattle fed with diets containing four dietary crude protein levels (10.5; 12; 13.5 and 15%), in dry matter base. there were used 24 non-castrated zebus steers, with initial mean live weight of 398.4 kg, and allotted to randomized blocks design with four treatments and six replications. the experiment lasted 78 days and was divided in three periods of 21 days after 15 days of adaptation. the fecal production was estimated by the indigestible acid detergent fiber (iadf), after in situ incubation period for 144 hours. the dietary protein levels, except for the increased cp and the linearly decreased ee and nfc intakes, did not influence the nutrients intake. the total apparent digestibility of nutrients was not influenced by the diets, except for cp and ee, which presented positive and negative linear relations, respectively, with the inclusion of dietary crude protein. the daily mean gain of live weight, carcass yield and food conversion were not also influenced by the diets, recording means values of 1, 074 g/day, 51.43% and 10.01, respectively. based on these results, it is recommended the use of 10.5% of cp in the diet for beef cattle, in the termination phase, with initial live weight close to 400 kg.
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