Data/hora: 27/07/2024 03:07:02

Biblioteca(s): 	Embrapa Pantanal.	
Data corrente: 	13/09/1995	
Data da última atualização: 	23/09/2013	
Autoria: 	MERTENS, D. R.; ELY, L. O.	
Título: 	Evaluating forage characteristics using a dynamic model of fiber disappearance in the ruminant.	
Ano de publicação: 	1978	
Fonte/Imprenta: 	In: SOUTH PASTURE FORAGE CROP IMP. CONFERENCE, 35., 1978, [S.l.]. Proceedings. [S.l.: s.n.] 1978. p.49-64.	
Idioma: 	Inglês	
Conteúdo: 	A dynamic model of fiber disappearance from the digestive tract of ruminants was developed upon accetable and defensible concepts of fiber digestion and passage kinetics, and coefficients obtained from available literature. The model has applicability, manageability and comparability to experimental observations. Although the model can simulate the effects of some forage and animal chracteristics upon digestion, it should be realized that it is only the initial component of an overall rumen function model. Specific limitations of the present model include the aggregation of microbial interactions with fiber and fiber characteristics into the digestion rate constants and the assumption that fiber digestion is not limited by factors other than fiber characteristics. Development and use of the model suggested the need for additional information in several aspects of ruminant digestive function. More research is needed concerning particle size reduction, including: (1) particle size distributions in feed, digestive tract and feces; (2) changes in particle size in the rumen associated with rumination and chewing; and (3) description of particle size reduction as a factor influencing rate of passage. Information is also needed is describing digestion such as the effect of : (1) particle size; (2) microbial interaction; and (3) chemical, morphological or physical plant characteristics upon digestion rate. Additional research is also needed to obtain usable rate of passage coefficients under a variety of animal states and dietary situations. Although improvement of the model of fiber disappearance in ruminants will need to continue as new information is ccumulated, it can be used in its present form to assess some factors that influence forage quality. Simulation of the model provides controlled evaluation of the beneficial effects of grinding and pelleting forages. Analysis of plant and canimal characteristics that influence digestion and intake suggests that the proportion of the NDF in the indigestible fraction and rate of passage influence the maximum intake of digestible dry matter more than rate of digestion.	
Palavras-Chave: 	Avaliacao; Dynamic model; Evaluation; Fiber disappearance; Modelo dinamico; Ruminant.	
Thesagro: 	Forragem; Ruminante.	
Thesaurus Nal: 	forage.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (29695-1) - ADD - SP - -- - SP1170 -  - 1170 - DIS