Toxic Effects of Ochratoxin A on Calcium Metabolism during Chick Embryo Developmentand in Hatched Chicks

The present study was carried out to study the effect of inovo ochratoxin A (OTA) injection in Highline layer eggs on calcium metabolism and blood biochemical parameters of embryos and after the hatch. At day 10 of embryonic development, one hundred and sixty-two fertile eggs were individually weighed and divided into two equal treatments. The first treatment (control) consisted of the individual injection of fertile eggs with 50 μL sodium carbonate. In the second treatment (OTA), fertile eggs were individually injected with 12.5 ng OTA dissolved in 50 μL sodium carbonate. On days 12, 14, and 16 of incubation and at the hatch, serum calcium and inorganic phosphorus concentrations were lower (p<0.05), while sodium, alkaline phosphatase and triiodothyronine concentrations were higher (p<0.05) in the OTA-injected eggs compared with the controls. Serum potassium concentration was not affected (p<0.05) by OTA treatment. Lower calcium and phosphorus levels were determined (p<0.05) in the allantoic fluid of OTA-injected eggs compared with the controls. On days 12, 14, and 16 of incubation and at the hatch, lower whole body and yolk calcium and phosphorus, but not sodium levels, were measured (p<0.05) in the OTA treatment compared with the controls. In conclusion, the injection of eggs with OTA reduced blood calcium and phosphorus levels, which were associated with reduced whole body and yolk content from these electrolytes. Therefore, ochratoxin A had a negative effect on calcium metabolism.