Relative bioavailability of manganese proteinate for broilers fed a conventional corn-soybean meal diet.

An experiment was conducted to investigate the bioavailability of organic manganese proteinate (Mn) relative to inorganic Mn sulfate for broilers fed a conventional corn-soybean meal basal diet. A total of 448-day-old Arbor Acres commercial male chicks were fed the Mn-unsupplemented basal diet (control) or basal diet supplemented with 60, 120, or 180 mg Mn/kg from each Mn source. At 21 days of age, heart tissue was excised for testing DM, Mn concentration, manganese superoxide dismutase (MnSOD) activity, and MnSOD mRNA level. The Mn concentration, MnSOD activity, and MnSOD mRNA level in heart tissue increased (P < 0.01) linearly as dietary manganese concentration increased. Based on slope ratios from multiple linear regressions of the above three indices on added Mn level, there was no significant difference (P > 0.21) in bioavailability between Mn proteinate and Mn sulfate for broilers in this experiment.