Pharmacokinetics of some inorganic and organic zinc compounds in broiler chickens

Abstract. The pharmacokinetics of zinc was investigated in broiler chickens after single intraingluvial application at a dose of 50 mg/kg of either 5% zinc methionate or 5% zinc sulfate solutions. Serum zinc concentrations were assayed spectrophotometrically on a biochemical analyser. Pharmacokinetic parameters were determined by the compartmental method and by non-compartmental analysis by means of specialised pharmacokinetic software. Results were statistically processed by one way ANOVA and Mann-Whitney’s test using statistical software. The intraingluvial application of the two tested zinc compounds resulted in statistically significantly higher serum concentrations after zinc sulfate administration from post treatment hours 2 and 12. During the first two hours after crop intubation, blood zinc levels did not differ statistically significantly between both compounds, but were higher after zinc sulfate application. In the alimentary tract of broiler chickens, zinc methionate was absorbed more rapidly than zinc sulfate. It was also distributed at a higher volume as compared to the inorganic salt. The maximum serum zinc concentrations were statistically significantly higher after zinc sulfate application than after zinc methionate treatment. Elimination half-life (T1/2) and mean residence time (MRT) values determined by the two pharmacokinetic models were similar and the differences between them – statistically insignificant.