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Chemical composition and carbohydrate fractionation of Panicum maximum cv. TanzÃnia biomass under three rest periods. / ComposiÃÃo quÃmica e fracionamento dos carboidratos da biomassa de panicum maximum cv. TanzÃnia sob trÃs perÃodos de descanso.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O experimento foi conduzido no campo avanÃado do NÃcleo de Pesquisa em Forragicultura - NPF (www.npf.ufc.br) localizado na Fazenda Experimental do Vale do Curu â FEVC, pertencente à Universidade Federal do Cearà â UFC. Objetivou-se avaliar a composiÃÃo quÃmica e o fracionamento dos carboidratos da biomassa de Panicum maximum cv. TanzÃnia sob trÃs perÃodos de descanso (PDs) baseados no nÃmero de novas folhas expandidas por perfilho (1,5; 2,5 e 3,5F). Utilizou-se o delineamento inteiramente casualizado em arranjo fatorial 3x3 (3 fraÃÃes e 3 PDs). A colheita das amostras foi feita antes da entrada e apÃs a saÃda dos animais dos piquetes. Posteriormente, as amostras foram separadas nas fraÃÃes folha, colmo e material morto. No LaboratÃrio de NutriÃÃo Animal do Departamento de Zootecnia da UFC (LNA/DZ/UFC), foram determinados os teores de Fibra em Detergente Neutro (FDN), Fibra em Detergente Ãcido (FDA), Hemicelulose (HEM), Celulose (CEL), Lignina (LIG), Extrato EtÃreo (EE), ProteÃna Bruta (PB), NitrogÃnio InsolÃvel em Detergente Neutro (NIDN), NitrogÃnio InsolÃvel em Detergente Ãcido (NIDA), Carboidratos Totais (CT), Carboidratos NÃo Fibrosos (CNF), e das fraÃÃes que compÃem os CT: A+B1, B2 e C. Os teores de FDN e de FDA foram elevados (P<0,05) com o avanÃo dos PDs. A planta inteira (PI) do pasto sob maior PD (3,5F), no prÃ-pastejo, apresentou teores, respectivamente, de 74,0 e 46,3% sendo estes elevados para 77,3 e 50,9% no pÃs pastejo. Os teores de LIG da fraÃÃo folha do pasto sob PD 3,5F (4,2%) sofreram elevaÃÃes (P<0,05) no prÃ-pastejo. Os teores de LIG na PI foram superiores (P<0,05) naquelas submetidas ao PD 3,5F em comparaÃÃo Ãs PIs do PD 1,5F tanto no prÃ-pastejo (4,7 e 5,3%) quanto no pÃs-pastejo (4,7 e 5,3%). Os maiores teores de PB da fraÃÃo folha foram encontrados nos pastos sob PD 1,5F (10,9 e 8,6%), no prà e pÃs-pastejo. Os teores de PB na planta inteira variaram de 8,8 a 6,4% (P<0,05) e 6,2 e 4,4% (P<0,05) entre os PDs 1,5 e 3,5F, respectivamente no prà e pÃs-pastejo. Os teores de NIDA, tambÃm foram elevados (P<0,05) na PI do PD 3,5F (20,3 e 28,5%), respectivamente no prà e pÃs-pastejo. Os teores de CT da fraÃÃo folha e da PI apresentaram teores
mÃdios (P>0,05) de 75,4 e 77,4% no prÃ-pastejo e 79,2 e 89,2% no pÃs pastejo. A fraÃÃo C dos carboidratos apresentou variaÃÃo mÃdia de 11,4 a 11,9%, na fraÃÃo folha, enquanto que na PI do pasto sob PD 3,5 F, foram observados os maiores teores (P<0,05) desta fraÃÃo (14,4 e 15,7%), em ambos os casos quando observados no prà e pÃs-pastejo. O pasto de capim TanzÃnia manejado sob PD 1,5F apresentou a melhor composiÃÃo quÃmica dos que foram avaliados. Contudo à necessÃrio que informaÃÃes sobre a composiÃÃo quÃmica dos pastos sejam levadas em consideraÃÃo em conjunto com as mudanÃas ocorridas na estrutura do pasto para que se possa ter uma maior exatidÃo na avaliaÃÃo da qualidade dos pastos. / The experiment was carried out in the advanced field of the Forage Research Sector - NPF (www.npf.ufc.br) located in the Experimental Farm of the Vale do Curu - FEVC, belonging to Federal University of Cearà - UFC. The objective was evaluate the chemical composition and the carbohydrate fractionation of Panicum maximum cv. TanzÃnia biomass under three rest periods (RPs) based in the new leaf (L) number expanded for tiller (1.5; 2.5 and 3.5L). Was used the completely randomized design in a factorial arrangement 3x3 (3 fractions and 3 RPs). The harvest of the samples was made before the entrance and after the exit the animals the poles. Later, the samples had been separate in the fractions leaf, culm and death material, being droughts in greenhouse of forced ventilation 65 C for 72 hours, and processed. In the Laboratory of Animal Nutrition of the Animal Science Department of UFC (LNA/DZ/UFC), were determined the levels of Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), Hemi-cellulose (HC), Cellulose (CEL), Lignin (LIG), Etereal Extract (EE), Crude Protein (PB), Insoluble Nitrogen in Neutral Detergent (INND), Insoluble Nitrogen in Acid Detergent (INAD), Total Total Carbohydrates (TC), Non Fiber Carbohydrates (NFC), and of the fractions that compose the TC: A+B1, B2 and C. The levels of NDF and ADF had been raised (P<0.05) with the advance of the RPs. The entire plant (EP) of the grass under bigger RP (3.5L), in the before grazing, presented levels, respectively, of 74.0 and 46.3% being these raising for 77,3 and 50,9% after grazing. The levels of LIG of leaf fraction of the grass under RP 3.5L (4.2%) had suffered rises (P<0.05) after grazing. The LIG levels in the RP were higher (P<0.05) in those submitted to 3.5L RP in comparison to the EPs of the 1.5L RP in such a way in before grazing (4.7 and 5.3%) how much after grazing (4.7 and 5.3%). The biggest levels of PB of the leaf fraction had been found in the grass under 1.5L RP (10,86 and 8.59%), before grazing and after grazing. The levels of CP in the entire plant had varied of 8.8 6.4% (P<0.05) and 6.16 and 4.4% (P<0.05) between 3.5 and 1.5L RPs, respectively before and after grazing. The INAD levels, had been also raised (P<0.05) in the EP of 3.5L RP (20.3 and 28.5%), respectively before and
after grazing. The levels of TC of the leaf fraction and the EP had presented average levels (P>0.05) of 75.4 and 77.4% before grazing and 79.2 and 89.2% after grazing. The C carbohydrates fraction presented average between 11.4 11.9%, in the leaf fraction, whereas in the EP of the grass under 3.5L RP, had been observed biggest levels (P<0.05) of this fraction (14.3 and 15.7), in both cases when observed before grazing and pos-grazing. The TanzÃnia grass under 1.5L RP presented the best chemical composition of that they had been evaluated. However, it is necessary that information on the chemical composition of the grass are taken in consideration in set with the occured changes in the structure of the grass so that if can have a bigger exactness in the evaluation of the quality of the grass.

Identiferoai:union.ndltd.org:IBICT/oai:www.teses.ufc.br:1272
Date21 February 2006
CreatorsJosemir de Souza GonÃalves
ContributorsMagno Josà Duarte CÃndido, Josà Neuman Miranda Neiva, Maria Socorro de Souza Carneiro
PublisherUniversidade Federal do CearÃ, Programa de PÃs-GraduaÃÃo em Zootecnia, UFC, BR
Source SetsIBICT Brazilian ETDs
LanguagePortuguese
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis
Formatapplication/pdf
Sourcereponame:Biblioteca Digital de Teses e Dissertações da UFC, instname:Universidade Federal do Ceará, instacron:UFC
Rightsinfo:eu-repo/semantics/openAccess

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