Particle size reduction and passage rate of digesta through the gastro-intestinal tract of cattle fed orchardgrass [Dactylis glomerate] hay
1992
Oshio, S. (National Grassland Research Inst., Nishinasuno, Tochigi (Japan))
Particle size reduction and passage rate of orchardgrass hay through the gastrointestinal tract were investigated in cattle fitted with oesophageal, rumen, or duodenal fistulae. 1) Particle size (length) of ingested hay was reduced from 24 to 1.5 cm in the boli by mastication during eating. 2) Ruminal digestion did not affect appreciably particle size reduction in the rumen, while rumination enabled to reduce the particle size. 3) The particle size of the duodenum content and faeces showed a similar distribution pattern. 4) Four markers were used to analyze the passage rates of digesta through the digestive tract of cattle. Passage rate of the markers through the whole digestive tract was higher in the order of polyethylene glycol 4000 (water soluble marker) chromium oxide powder (insoluble solid marker) = stained feacal particles (particles that can pass in the rumen) stained long hay (particles that cannot pass in the rumen). The difference in the passage rate among the markers used was analyzed in connection with the particle size reduction or degradation in the rumen or retention time in the abomasum
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