Bioavailabilities of calcium, phosphorus and magnesium from whey mineral complex in growing male rats

The bioavailabilities of Ca, P and Mg from whey mineral complex (WMC) were studied from the viewpoint of the mineral balance and bone properties in growing male rats and compared with bovine bone ash (BBA) and CaCO3. Ca source showed no significant effect on feed intake, body weight gain or feed efficiency (p < 0.05). When the dietary Ca level was 0.3%, the dry weight of the femur in rats fed WMC was significantly higher than that in rats fed BBA. The femur P content of rats fed 0.3% Ca as WMC was significantly higher than that of rats fed BBA or CaCo3. The breaking energy of the femur from rats fed WMC was significantly higher than that from rats fed BBA at a Ca level of 0.2% or 0.3%. There was the same tendency in bone densities as was observed in breaking properties. There was no significant difference in quantitative values for Ca balance among three groups of rats, whereas those rats fed WMC had a significantly higher P retention than other groups. Ca bioavailability from WMC and the effect on the utilization of P and Mg were discussed.