Quatro pôneis miniaturas adultos e castrados foram sorteados aleatoriamente para um quadrado latino 4x4. Os tratamentos se constituíram em 4 diferentes níveis de zeolita de sódio (ZSA) no suplemento mineral 0; 1,26; 2,54 ou 4, 0%. Todos os animais passaram por fases de depleção intercaladas com fases de tratamentos. A dieta foi formulada na razão 30:70 de feno de Cynodon dactylon e concentrado respectivamente. Nos últimos 4 dias de cada fase os animais eram colocados em gaiolas metabólicas e procedia-se a coleta total de fezes e urina. A analise comparativa dos resultados foi efetuada através dos testes F e de Duncan. Não se observou efeito positivo (P > 0,05) da ZSA na absorção de cálcio. No caso do fosforo ao contrario do que se esperava a ZSA teve efeito positivo para Mg, Cu, Zn e Mn, não houve interferência da ZSA no metabolismo dos mesmos. Efeito negativo da ZSA no metabolismo do K e Na constatou-se (P > 0,05). Não houve efeito aparente da inclusão da zeolita de sódio sobre o metabolismo dos minerais para os níveis testados e metodologia utilizada

This work was conducted to verify the sodium zeolite A (SZA) effect on Ca, P, Mg, K, Na, Cu, Zn, Fe and Mn absorption and retention when fed to Miniature Ponies. Four mature gelding Miniature Ponies were assigned to a 4 x 4 Latin Square experimental. A random numbers table was used to assign horses to dietary treatment groups in each period. Treatment groups D, A, B and C diets were supplemented with 0, 1.26, 2.54 or 4.0% sodium zeolite A (SZA), respectively, on an as fed basis. The project was conducted in 4,28 days periods divided in two phases. In the first phase alI horses were fed the depletion diet and in the second phase alI of them were fed the experiment diets. The depletion diet was. formulated to meet de NRC (1989) requirements for energy and protein, but, to be deficient in alI macro and micro mineraIs to stimulate depletion of the labile pool of mineraIs in order to creat a demand for mineraIs in a repletion period. The experiment diet was formulated to be 30:70 Cynodon dactylon hay and concentrate, respectively. The concentrate had 80% of a 13.5% protein peleted ration and 20% of mineral supplements (treatments A, B, C or D). The feed offered was calculated as 1.5% of body weight basis. Every week, the horses were weighed and the feed adjusted to their body weight. During the last 4 days of every phase, the horses were confined individually in metabolism creates, and the total collections of feces and urine were made. The feces and urine were weighed and measured, and a 10% sample of each was taken and frozen for later analyses. The feed was sampled every day and a composite sample was taken in the end of the trial. The procedure for digestion of the samples (urine, feces and feed) was carried out as by PARKINSON & ALLEN (1975) and the concentration of mineraIs was determined by a Inductively-Coupled Plasma Emission Spectrophotometer (ICP). Data were analysed using the F and Duncan tests. Calcium absorption was not affected by SZA (p > 0,05). Calcium retained (g/d), retained (% intake), retained (% absorption) were greater at the 0% leveI of SZA. Phosphorus retained (% absorption) was greater at the highest leveI of SZA (4%), showing that, phosphorus was instead positivelly affected by SZA (P > 0,05). Magnesium, Cu, Zn and Mn were unaffected by SZA; but, SZA negativelly affected K and Na. Potassium absorved (g/d) and Na retention (% intake) were greater at the 0% leveI of SZA (P > 0,05) the results obtained for Fe are not reliable because was subject to gross interference being present in alI biological material (JANKOWIAK & Le VIER, 1971). It seemed that the use of SZA did not affected mineral metabolism at the leveIs tested or the techniques utilized in this trial