Utilization of equations to predict carbohydrate fractions in some tropical grasses

Autor(es)

Fukushima, Romualdo S. ^[1] ; Bacha, Carolina B. ^[1] ; Fuzeto, Adriana P. ^[1] ; Port, Ana Carolina R. ^[1] ; Herling, Valdo R. ^[2] ; Velasquez, Alejandro V. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Fac Med Vet & Zootecnia, Dept Nutr & Prod Anim, BR-13630900 Pirassununga, SP - Brazil

^[2] Univ Sao Paulo, Fac Zootecnia & Engn Alimentos, Dept Zootecnia, BR-13630900 Pirassununga, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ANIMAL FEED SCIENCE AND TECHNOLOGY; v. 208, p. 12-22, OCT 2015.
• Citações Web of Science: 1

Resumo

The chemical composition of five grasses, divided into stem and leaf, at three maturity stages, was used to predict carbohydrate fractions by equations based either on the Cornell Net Carbohydrate and Protein System (CNCPS) or equations from our research group. CNCPS carbohydrate fractions are estimated based on the NDF analysis. However, NDF does not include pectic substances and other neutral detergent (ND) soluble polysaccharides such as beta-glucans, galactans, etc. that are part of the cell wall matrix. Since NDF does not represent the complete plant cell wall, a crude cell wall (CW) preparation, which represents plant cell wall matrix more completely because it preserves those carbohydrates that otherwise would be solubilized by the ND solution, was used in equations to predict carbohydrate fractions. By substituting NDF for CW, it was found that pectin and other neutral detergent soluble polysaccharides (soluble fiber, SF) actually appeared in the fraction A of CNCPS, the rapidly degradable carbohydrate pool, instead of fraction B-1, as proposed in the original CNCPS model. However, location of SF in the fraction A seems inappropriate since the degradation rate of SF is lower than other fraction A components. Thus, an alternative could be to place SF in a specific carbohydrate fraction (B-2). This B-2 fraction (SF) can be estimated by subtracting NDF from the CW preparation. Because in the original CNCPS model the slowly degradable cell wall carbohydrates were assigned as fraction B-2, we suggest naming this carbohydrate pool a new fraction, B-3. With this arrangement, the fraction B-1 would be constituted only of starch. Carbohydrate pools must be adequately estimated so that rate and extent of forage degradation will be valuable tools to optimize animal performance. Simplified and easy-to-use equations to estimate carbohydrate fractions are proposed. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 03/11089-0 - Implicacoes de metodos analiticos para lignina na determinacao das fracoes de carboidratos de algumas plantas forrageiras tropicais.
• Beneficiário: Carolina Barbosa Bacha
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 02/05854-3 - Validação de um novo método analítico para quantificar o teor de lignina em alguns materiais lignocelulósicos (forrageiras, sub-produtos agroindustriais, madeiras e outros produtos vegetais) pertencentes à importantes segmentos do agronegócio
• Beneficiário: Romualdo Shigueo Fukushima
• Modalidade de apoio: Auxílio à Pesquisa - Regular