BACKGROUND: Balance in the amount of minerals in the aquatic animal’s diet is very important. Phosphorus is one of the most important minerals in fish and aquatic animal’s nutrition. Phosphorus is important not only for the proper growth and fish health, but also for excessive phosphorus excretion that may cause water pollution and algal bloom. OBJECTIVE: In this study the effects of adding monoammonium phosphate in the diet of fish (Cyprinus carpio Koi) and its comparison with monocalcium phosphate were investigated. METHODS: 650 koi fish weighing 17 g were distributed in 15 tanks (5 treatments - each in three replicates) and mono-ammonium phosphate-fed diets at three levels (0.75, 1.5 and 3% of the diet), monocalcium phosphate in one level (3% of the diet) and a control group (no phosphorus supplementation) were fed for 8 weeks. RESULTS: Growth indices and feed conversion ratio in fish fed 3% monoammonium phosphate showed the best results. The control group showed the lowest weight gain and the highest feed conversion ratio. Blood phosphorus was also significantly correlated with increasing monoammonium phosphate. The highest level of calcium in the blood was observed in the group fed monocalcium phosphate (3%). CONCLUSIONS: Considering the improvement of growth and nutrition indices, adding 1.5 to 3% monoammonium phosphate in the diet of koi fish was suggested.

L-lactic acid and D,L-lactic acid infusion in ponies resulted in metabolic acidosis with high anion gap (AG). Increased AG was explained entirely by increased blood L- and D-lactate concentrations. Hydrochloric acid infusion caused metabolic acidosis with decreased AG. Saline (NaCl) infusion caused mild metabolic acidosis, with no significant change in AG. Plasma K+ concentration was decreased by all types of infusions, with a maximum of 0.50, 0.25, 0.40, 0.50 mmol/L below baseline at the end of infusion in the L-lactic acid-, D,L-lactic acid-, HCl-, and NaCl-infused ponies, respectively. Only hydrochloric acid had a tendency to increase plasma K+ concentration. Hypophosphatemia developed in NaCl- and HCl-infused ponies, but not in the D,L-lactic acid-infused ponies. Serum inorganic phosphate concentration in L-lactic acid-infused ponies increased initially, but was significantly (P < 0.05) lower than values in the other ponies at 4 hours after onset of infusion. In ponies, the effect of acidemia on plasma K+ and serum inorganic phosphate concentrations was similar to that reported for other species. Changes were small in magnitude and depended on the nature of the acid anion. Results indicate that large changes in plasma K+ and serum inorganic phosphate concentrations during acidosis are probably not a direct result of acidemia.

Samples of serum and urine were obtained simultaneously from 56 healthy lactating cows to determine ranges of fractional excretion (FE) of calcium (Ca), phosphate (PO4), magnesium (Mg), sodium (Na), potassium (K), and chloride (Cl). Samples were obtained at 3 stages of lactation: period 1 = 1 to 7 days, 2 = 83 to 112 days, and 3 = 175 to 197 days. The FE of electrolytes were significantly different among periods 1, 2, and 3 for Ca (P < 0.001), PO4 (P < 0.025) and Mg (P < 0.025), but were not significantly different for Na, K, and Cl. Least squares mean FE of Ca was lowest in period 1 and not significantly different for periods 2 and 3, whereas mean FE values for PO4 and Mg were highest in period 2 and not significantly different for periods 1 and 3. The mean FE values of Na, K, and Cl did not change with stage of lactation. Age and category of milk production (high, medium, and low) did not influence the FE values of the electrolytes.