부산대학교 도서관

Gut capacity is an important factor in digestive physiology and is often measured as dry matter fill (DMF) following dissection, which prevents repeated measures in the same animal. It was proposed to calculate DMF from food intake, digestibility, and gut mean retention time (MRT), but empirical tests of this are few. We calculated DMF from intake, digestibility, and the MRT of small-particle (1 mm) and large-particle (20 mm) markers in 20 sheep (Ovis aries L., 1758) fed at different intake levels and compared results with DMF at dissection at the end of the feeding trial. MRT for smaller particles was significantly shorter than for larger particles (34.4 ± 6.1 vs. 42.5 ± 7.6 h, respectively). Correspondingly, DMF calculated from smaller particles (0.98 ± 0.27 kg) was significantly lower than DMF calculated from larger particles (1.20 ± 0.30 kg). The latter was not significantly different from DMF measured at dissection (1.18 ± 0.34 kg). These results suggest that DMF can be estimated from measures of digestive physiology. The choice of particle marker to determine MRT is crucial for the accuracy of the proxy. In ruminants, where small particles are consistently eliminated faster than larger particles, considerations of marker particle size are particularly important. Key words: herbivore, ruminant, particle size, passage, gut capacity, sheep, Ovis aries. La capacite du tube digestif, un facteur important en physiologie digestive, est souvent mesuree comme etant le volume de matiere seche (DMF) au moment de la dissection, ce qui empeche des mesures repetees pour le meme animal. S'il a ete propose de calculer le DMF a partir de l'ingestion d'aliments, de la digestibilite et du temps de retention moyen (MRT) dans le tube digestif, il existe peu de tests empiriques. Nous avons calcule le DMF a partir de l'ingestion d'aliments, de la digestibilite et du MRT d'un petit (1 mm) et d'un grand (20 mm) marqueurs particulaires chez 20 moutons (Ovis aries L., 1758) nourris selon differents degres d'ingestion, et compare les resultats avec les DMF mesures apres la dissection a la fin de l'essai d'alimentation. Le MRT pour les petites particules etait significativement plus court que pour les grandes particules (34,4 ± 6,1 contre 42,5 ± 7,6 h, respectivement). Ainsi, le DMF calcule a partir des petites particules (0,98 ± 0,27 kg) etait significativement plus faible que le DMF calcule pour les particules plus grandes (1,20 [+ or -] 0,30 kg), ce dernier n'etant pas significativement different du DMF mesure apres la dissection (1,18 ± 0,34 kg). Ces resultats donnent a penser que le DMF peut etre estime a partir de mesures de la physiologie digestive. Le choix du marqueur particulaire utilise pour determiner le MRT est d'importance cruciale pour l'exactitude de l'estimation. Pour les ruminants, chez lesquels les petites particules sont uniformement eliminees plus rapidement que les particules plus grandes, les considerations touchant a la taille du marqueur particulaire sont particulierement importantes. [Traduit par la Redaction] Mots-cles: herbivore, ruminant, taille des particules, passage, capacite du tube digestif, mouton, Ovis aries.
Introduction In the interplay of various anatomical and physiological adaptations that form the digestive strategies of herbivores, gut capacity is an important factor that influences all other measures (Hume 2005; [...]