Effects of meal size and feeding frequency on selected postprandial blood and urine variables in bottlenose dolphins (Tursiops truncatus)

Title from first page of PDF file (viewed September 16, 2010)Includes bibliographical references (p. 33-35)Atlantic bottlenose dolphins (Tursiops truncatus) in managed collections may be at increased risk for various chronic health issues including insulin resistance, hemochromatosis, nephrolithiasis, and hypocitraturia. To assess the impact of meal size and feeding frequency on biochemical markers, a prospective intervention study was developed to determine the effects of various feeding schedules on selected blood and urine variables during four feeding phases. Blood and urine samples were collected weekly during a 6-week standard feeding schedule (average six meals per day over eight hours), a 6-week continuous feeding schedule (twelve meals per day over twelve hours), a 3-week recovery period (same as standard feeding schedule), and a 6-week bulk feeding schedule (two meals per day over six hours). Repeated measures analysis of variance was used to compare postprandial mean blood and urine data collected over a 21-week period from six bottlenose dolphins at the U.S. Navy Marine Mammal Program in San Diego, California. Most changes were observed during the bulk feeding intervention including significantly increased levels of serum gamma-glutamyl transpeptidase, triglyceride and urine creatinine as well as significantly decreased levels of urine uric acid and uric acid/creatinine. Serum cholesterol significantly increased during the continuous feeding intervention when compared to the standard feeding schedule. Significance was also observed when comparing estimated glomerular filtration rates among the four feeding phases. Findings were consistent with human studies assessing meal size and frequency as determinants of chronic health. Findings were also consistent with studies assessing the effects of high-protein diets on both animals and humans. Overall, it seems that a diet more similar to that of wild dolphin populations (continuous feeding) may be beneficial for dolphins that are at increased risk of chronic health issues such as hemochromatosis and nephrolithiasis