engleski

Calcium, phosphorus, zinc and their ratios in serum of fattening swine fed different diets in respect to zinc

The influence of zinc supplementation in diets which contained constant concentrations of calcium and phosphorus, on serum concentrations of calcium, phosphorus and zinc and their molar ratios was investigated in fattening German Landrace x Pietrain x Large White x Swedish Landrace weaned crossbreds. Bioavailability of zinc from Zn-methionine was found to be significantly better than that of zinc from ZnSO4 in the period of fast growth and body mass gain. The characteristic time profile for Zn in serum was observed in all experimental groups but at different zinc levels. No marked influence of dietary supplemented zinc from either organic or inorganic source on serum Ca and P concentrations was recorded. Moreover, a consistent trend of P/Ca values following supplementation of zinc was not found. The supplemented zinc from both organic or inorganic source led to lasting decreases of P/Zn and Ca/Zn values. Therefore, these ratios may be used as reliable indicators of Zn status in swine: P/Zn <=300 and Ca/Zn <=200 would indicate physiological concentrations of zinc in serum of pigs. Contrary to this the appearance of parakeratosis might be expected at low levels of zinc and relatively high Ca/Zn and P/Zn ratios.

pigs; nutrition; Zn; Ca; P; ratios

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