Effect of Manganese Source on Manganese Absorption by the Intestine of Broilers

Abstract

Two experiments were conducted to investigate the effect of Mn source on Mn absorption by the intestine of broilers. In Experiment 1, the effect of Mn source, including MnSO4, 2 Mn-amino acid chelates (Mn-Gly and Mn-Met) synthesized in our laboratory, 3 Mn-amino acid complexes with different complex strengths (Mn-Met E, Mn-AA A, and Mn-AA B), and 2 mixtures of MnSO4 with Gly or Met, on Mn absorption was assessed with ligated loops of different small intestinal segments of broilers. In Experiment 2, the absorption of Mn from MnSO4, Mn-AA A, and Mn-AA B was compared with intact broilers fed ad libitum. The criterion used for comparison was the Mn content of hepatic portal vein plasma. The absorption of Mn was higher (P < 0.0002) by ligated ileal loops than by duodenal and jejunal ones. Met supplementation increased (P < 0.03) the absorption of Mn as MnSO4. The absorption of Mn as Mn-AA A and Mn-AA B with moderate and strong complex strengths, respectively, were higher (P < 0.05) than those of Mn as MnSO4 and Mn-Met E with weak complex strength. On d 7 and 9 of Experiment 2, the Mn content of portal vein plasma was higher (P < 0.03) for Mn-AA B with strong complex strength than for MnSO4. On d 9, Mn content in plasma was higher (P < 0.01) for Mn-AA B with strong complex strength than for Mn-AA A with a moderate one. The results from this study confirm that the ileum was the main site of Mn absorption for broilers, and Met was more effective in facilitating Mn absorption than Gly as a ligand. Organic Mn was more efficiently absorbed than inorganic Mn (MnSO4); the absorption of organic Mn with moderate and strong complex strengths was greater than that of the organic Mn, which was weak, and the absorption of organic Mn with strong complex strength was greater than that of the organic Mn with a moderate strength.