Effect of dietary lipid level on lipid passage rate and lipid absorption efficiency in American robins (Turdus migratorius)

✍ Scribed by Zurovchak, Joseph G.; Stiles, Edmund W.; Place, Allen R.

• Book ID: 101228286
• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 260 KB
• Volume: 283
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/(sici)1097-010x(19990301/01)283:4/5<408::aid-jez10>3.0.co;2-m

✦ Synopsis

Thrushes consume a variety of fruit that differ greatly in nutrient composition, especially lipid content. Thrushes may be efficient at extracting energy from fruit diets by changing how they digest meals differing in lipid content. We tested for this capability in American robins (Turdus migratorius) by acclimating them to diets differing in lipid content and measuring passage rate and absorption efficiency of ingested lipids with radiolabeled markers. Birds acclimated to high-lipid (26% and 40% dwt) diets ingested less dry matter and retained ingested lipids in their gastrointestinal tract three times longer than when acclimated to a low-lipid (9%) diet. Absorption efficiency did not differ among diets (~74%), suggesting robins minimize feeding time rather than maximize rate of energy gain when processing meals. Thus, robins slowed intake and passage rate of dietary lipids with increasing dietary lipid concentration while maintaining a steady lipid absorption efficiency.