This study aimed to evaluate the chemical composition of water wells and to discuss the results in relation to nutritional requirements and tolerance limits of domestic ruminants. Ten samples of water wells (three replicates) from Brazilian semi-arid were collected and analyzed for their macro and trace minerals levels. A variation was found in the mineral composition of the waters and the macro minerals presenting highest levels were Cl, Mg, Ca and Na, while the predominant trace minerals were Fe and Mn. The concentration of the examined minerals can provide a small contribution to the animal as in the case of P or supply a considerable amount as Cl. The levels of total dissolved solids found in the majority of the samples can be tolerable for ruminants. In some of the samples the presence of Pb, Cd and Cr was found in concentrations higher than the upper recommended limit for ruminants.

RESUMO

-The objective of this study was to evaluate water, mineral, feed and nutrient voluntary intakes, in addition to dry matter and nutrient digestibility and the nitrogen balance of lambs fed three mineral supplements. The first treatment consisted of solid salt residue (SSR) from an aquaculture tank; the second contained SSR from desalination waste; and the third treatment was control, which corresponded to the supplementation of a commercial mineral supplement. The study lasted 20 days, the first 15 of which were used for animals to adapt to the pens and diets, and the last five days were used for data collection. Twenty-four castrated male lambs with a body weight of 19.72±2.52 kg were utilized in the experiment. The mineral supplements evaluated did not affect the intake and digestibility of the dry matter and nutrients, the water and mineral-salt intake or nitrogen balance. Mineral supplements produced from the SSR from aquaculture tanks and from the desalination waste did not reduce feed, nutrient and water intakes or nutrient digestibility, which suggests that these raw materials can be used in the elaboration of mineral mixtures for lambs.

This study aimed to evaluate the mineral composition of solid residues (SR) from desalination waste (DWSR), saline water (SWSR) and aquaculture ponds (APSR), and to discuss the results based on ruminant requirements. Mineral determined were K, P, Ca, Mg, S, Cu, Fe, Mn, Zn, Na, Cl, Ni, Pb, Cd and Cr, from 24 samples, 4 DWSR, 10 SWSR and 10 APSR, with three replicates. Desalination waste solid residue, SWSR and APSR had large variation of minerals. Saline water solid residue and DWSR presented potential to be used as source of Na and Cl, while the APSR can contribute Ca. All examined saline sources were poor in P, Ca and trace minerals except the APSR, showing a considerable concentration of Ca. Some samples of SWSR and APSR presented mineral concentrations that may be potentially toxic to ruminants.