Effects of dietary fibre on digesta passage, nutrient digestibility, and gastrointestinal tract morphology in the granivorous mongolian gerbil (Meriones unguiculatus)

Citation
Yx. Pei et al., Effects of dietary fibre on digesta passage, nutrient digestibility, and gastrointestinal tract morphology in the granivorous mongolian gerbil (Meriones unguiculatus), PHYSIOL B Z, 74(5), 2001, pp. 742-749
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences",Physiology
Journal title
PHYSIOLOGICAL AND BIOCHEMICAL ZOOLOGY
ISSN journal
1522-2152 → ACNP
Volume
74
Issue
5
Year of publication
2001
Pages
742 - 749
Database
ISI
SICI code
1522-2152(200109/10)74:5<742:EODFOD>2.0.ZU;2-K
Abstract
To investigate digestive tract performance in Mongolian gerbils (Meriones u nguiculatus), food intake and digestibility, digesta passage rate, and gast rointestinal tract morphology were measured in captive animals fed low- or high-fibre diets. We used two markers (Co-ethylene diamine tetra-acetic aci d for solutes and Cr-mordanted cell walls for particles) to measure differe ntial passage rates of digesta fractions in order to test for the presence of a colonic separation mechanism (CSM). Although dry-matter intakes on the high-fibre diet did not differ from those on the low- fibre diet, digestib ilities of dry matter, neutral-detergent fibre, acid-detergent fibre, crude protein, and crude fat were all significantly lower on the high-fibre diet . Gross energy intake on the high-fibre diet also did not differ from that on the low- fibre diet, but energy lost in faeces was much higher than on t he low- fibre diet; thus, energy digestibility and digestible energy intake were significantly lower on the high-fibre diet. The lengths and dry-tissu e masses of all segments of the gastrointestinal tract tended to enlarge in response to increased dietary fibre, but only the total tract contents, co ntents of the small intestine, and length and dry-tissue mass of the caecum increased significantly. The mean retention time (MRT) of the particle mar ker was significantly greater than that of the solute marker on the low- fi bre but not the high-fibre diet; the solute/particle differential retention ratio was 0.62 on the low-fibre diet and 0.90 on the high-fibre diet. Thus , there was no evidence for selective retention of the solute marker on eit her diet. The MRT of the particle marker was significantly lower on the hig h-fibre diet and in the same direction as the MRT of the solute marker. The se results suggest that the granivorous Mongolian gerbil has no CSM but can adjust its digestive tract capacity to accommodate greater quantities of l ow-quality food.