Efetividade física da fibra para caprinos

• Autor(a) principal: Lopes, Daniel dos Santos
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5807
• topic: Caprinos; Rumen; Fibra; Exigência nutricional; Goats; Rumen; Fiber; Nutritional requirement; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::NUTRICAO E ALIMENTACAO ANIMAL::EXIGENCIAS NUTRICIONAIS DOS ANIMAIS

The present study presents as speculation the possibility of existence of interactions between both chemical and physical characteristics of forage plants acting on performance of small ruminants. The literature presents evidences of individual actions of those factors, but there is a lack on informations in respect to interactive effects. The objective of our work was to evaluate possible variations on feed intake, on rumen fiber mass of goats in different moments of the day according to alteration on source of forage offered as well as the particle size of that feed. We analyzed the combinations obtained among three levels of quality, named as high, medium and low based on age of the plant which was considered as 35, 50 and 60 days for haymaking of coast-cross (Cynodon dactylon), chopped to obtain three particle size (small, medium and long) by using an experimental randomized design in a 3 x 3 factorial arrangement with 6 repeats. Animals were non-castrated male Saanen and Alpine kids averaging 191 ± 4 days of age and body mass of 24.68 ± 3.17 kg. Granulometric profile of feed, refusals and ruminal content was evaluated by use of sieve openings of 4.76 mm, 2.38 mm, 1.19 mm, 0.70 mm and 0.297 mm. Mass and composition of fiber in the rumen were kept unaltered throughout the day. Values of fresh ruminal content, of DM, of fiber, of physically effective fiber, and of indigestible material did not differ among the different combinations between quality and particle size studied, nor to the average turnover time of dry matter and of fiber in the rumen. Average time of retention for lignin varied according to the quality of forage offered, with lower values for the hay of low quality, which implies in higher rate of ruminal passage of lignin to compensate the intake of lignified material. The higher intake of dry matter and NDF with the use of hay of low quality occurred as particles of higher size were offered allowing for selection of feed. Conversely, higher intake of NDF and lignin were observed as kids were offered high and medium quality hay chopped to present particles of small size. The higher intake of physically effective fiber was associated to hay with large particle size independent of the quality of the forage. We concluded that composition and fiber mass on rumen content of goats is not altered throughout of day and that the particle size associated with the higher intake varies with the quality of fiber which in turn influence the average turnover time of lignin in the rumen.