Mineral concentrations in whole mice and rats used as food

Abstract

Calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), manganese (MD), and zinc (Zn) concentrations were measured in whole mice (five sizes) and rats (six sizes). Ca concentrations increased with age in both mice (1.2–2.3%) and rats (1.9–3.3%). Mg levels ranged from 0.09 to 0.13% (mice) and from 0.11 to 0.18% (rats), with the medium-size class of both species having the highest values. Cu (7.9–19.2 and 10.8–60.6 mg/kg) and Zn (58.0–82.5 and 73.2–113.6 mg/kg) generally decreased with age in both species, while Mn levels tended to increase with age (0.2–13.1 mg/kg, mice; 6.2–28.3 mg/kg, rats). Fe values were highest in neonates and adult size classes, ranging from 113.4 to 181.3 mg/kg (mice) and 111.3 to 332.6 mg/kg (rats). Rats usually contained higher concentrations of individual minerals than equivalent age categories of mice, even though both were fed identical diets. All rodents analyzed generally met known dietary requirements of mammalian carnivores, but differences between mice and rats were apparent. Specific mineral nutrient requirements for carnivorous birds and reptiles have not been determined. © 1996 Wiley-Liss, Inc.