Protein, calcium and phosphorus requirements in the maintenance of captive-bred capybaras

The objective was to determine the nitrogen-protein, calcium and phosphorus requirements of adult capybaras (Hydrochoerus hydrochaeris) bred in captivity through a nutritional balance study under conditions that favored the occurrence of cecotrophy. In a completely randomized design with four replicates per treatment, 16 adult female capybaras were fed isocaloric diets containing four levels of nitrogen (11.4, 12.3, 15.4 and 18.4 g N/kg dry matter-DM); calcium (3.0, 3.5, 4.0 and 4.5 g Ca/kg-DM); and phosphorus (2.0, 2.3, 2.7 and 3.0 g P/kg-DM). After 10 days of adaptation, the collection of feces was carried out for five consecutive days. Immediately following fecal collection, the animals were housed in metabolic cages for two days for urine collection. During the fecal collection, capybaras were observed to perform on average 0.32±0.27 cecotrophy acts per hour. Regression analyses allowed for estimating daily requirements of 0.25 g digestible nitrogen/kg LW0.75, which equals 1.56 g of digestible protein/kg LW0.75. Likewise, the available calcium and phosphorus requirements in 0.30 g Ca/kg LW0.75 and 0.15 g P/kg LW0.75 were estimated. The requirements of digestible nitrogen, as well as those of available calcium and phosphorus for the maintenance of capybaras are lower than those of domestic and other wild animal species with zootechnical potential.