DIETARY FIBER INFLUENCES NUTRIENT UTILIZATION, GROWTH AND DRY-MATTER INTAKE OF GREEN IGUANAS (IGUANA-IGUANA)

Herbivory is an uncommon feeding strategy in lizards. Appropriate diet formulations for captive lizards should be based on performance measu res, yet few data are available on the effect of plant fiber on food i ntake, nutrient utilization and growth of captive herbivorous lizards. This study was conducted to determine the effect of three levels of d ietary fiber on dry matter intake, nutrient and energy metabolizabilit y and growth rate of the green iguana (Iguana iguana). Twenty-one capt ive iguanas were fed nutritionally complete diets containing three lev els of dietary fiber: 19, 24, and 27% neutral detergent fiber. The igu anas were fed each diet for at least 12 wk, and total excreta were col lected for 11.3 +/- 4.0 d (means +/- SEM, range of 7 to 25 d). Diets a nd excreta were analyzed for dry matter, organic matter, gross energy, neutral detergent fiber, acid detergent fiber, and acid detergent lig nin. The study was designed as a Latin square crossover. Across all di ets, dry matter intake was proportional to body mass(1.0) (BM). Growth rate was greater (P < 0.05) when iguanas were fed the low and medium fiber diets (2.2 and 2.4 g/d, respectively) than when fed the high fib er diet (1.4 g/d). However, mean daily dry matter intake of the three diets [7.2 g/(d . kg BM)] was not different. In general, digestibility of fiber fractions and the metabolizability of dietary energy decreas ed (P < 0.05) as the level of dietary fiber increased. These data sugg est that a diet containing less than 27% neutral detergent fiber shoul d be fed if rapid growth is to be sustained during intensive captive p roduction of green iguanas.