Excess manganese ingestion in the chick

Area of Science:

• Animal Nutrition
• Toxicology
• Trace Mineral Metabolism

Background:

• Manganese (Mn) is an essential trace element for poultry.
• Understanding the bioavailability and toxicity of different dietary manganese sources is crucial for optimizing poultry diets and preventing adverse effects.

Purpose of the Study:

• To investigate the effects of excess dietary manganese (Mn) on young chicks.
• To compare the Mn activity of four different manganese sources: MnCl2 . 4H2O, MnSO4 . H2O, MnO2, and MnCO3.

Main Methods:

• Two experiments were conducted using young chicks fed a corn-soybean meal diet supplemented with 3000, 4000, or 5000 mg/kg of Mn from different sources.
• Evaluated chick performance (growth, feed efficiency), blood parameters (hemoglobin, hematocrit), and tissue Mn concentrations (bile, liver, bone).

Main Results:

• High levels of Mn from manganese sulfate (MnSO4 . H2O) and manganese chloride (MnCl2 . 4H2O) slightly depressed chick growth.
• Manganese dioxide (MnO2) and manganese carbonate (MnCO3) did not negatively affect chick performance.
• MnO2 exhibited lower Mn activity compared to other sources, indicated by smaller changes in hemoglobin, hematocrit, and tissue Mn levels.
• Neutralizing the chloride ion in MnCl2 . 4H2O did not mitigate the adverse effects of excess Mn.
• Bone and bile Mn concentrations were better indicators of Mn intake than liver Mn or growth parameters.

Conclusions:

• The bioavailability and toxicity of dietary manganese sources vary significantly.
• Manganese sulfate and manganese chloride are more biologically active and potentially toxic at high levels than manganese dioxide and manganese carbonate.
• Bone and bile Mn concentrations serve as reliable biomarkers for assessing dietary manganese exposure in poultry.