Abstract

In order to test whether mineral recommendations for horses are likely to guarantee adequate mineral provision for tapirs (Tapirus spp.), we investigated the apparent absorption (aA) of macro- and microminerals in 18 tapirs from 5 zoological institutions in a total of 24 feeding trials with total faecal collection. Feeds and faeces were analysed for Ca, P, Mg, Na, K, Fe, Cu, and Zn. The resulting aA coefficients, and the linear relationships of apparently absorbable dietary mineral content to total dietary mineral content (per 100g dry matter), were compared to data for domestic horses. While there were no apparent differences in the absorption patterns for P, K, Na, K, Fe, Cu or Zn, both Ca and Mg absorption were distinctively higher in tapirs than in horses. Tapirs are browsers that are adaptaed to a diet of higher Ca content and higher Ca:P ratio than equids, and high absorptive efficiency for Ca might have evolved to ensure that high dietary Ca concentrations to not bind dietary P in the intestine and thus make it unavailable for hindgut microbes. Like in other hindgut fermenters, absorption coefficients for Ca increased with dietary Ca:P ratio, and urinary Ca:creatinine ratios increased with dietary Ca. Several zoo diets used were deficient in one or more minerals. When compared to faeces from free-ranging animals, faeces from zoo animals had higher concentrations of most minerals, probably indicating a lesser diluting effect of indgestible fibre in zoo animals.