Mineral Nutrition Research Division, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China.
Department of Animal Science, Southwest University Rongchang Capmus, Chongqing 402460, P. R. China.
Poult Sci. 2019 Oct 1;98(10):4994-5004. doi: 10.3382/ps/pez293.
An experiment was conducted to investigate the effect of manganese (Mn) source on Mn absorption and expressions of Mn, amino acid, and peptide transporters in the small intestine of broilers. A total of 320 Mn-deficient 15-day-old Arbor Acres male broilers were randomly assigned to 5 treatments with 8 replicates/treatment and 8 chicks/replicate and fed an Mn-unsupplemented control diet or the control diet supplemented with 110 mg Mn/kg from either MnSO4, or 1 of 3 organic Mn chelates with weak (OW), moderate (OM), or strong (OS) chelation strength for 14 D. The plasma Mn contents were higher (P < 0.03) in supplemental Mn groups than in the control group, in OS group than in OM group, and in OM group than in OW and MnSO4 groups on day 28. Broilers fed diets supplemented with Mn had higher (P < 0.02) duodenal divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1) mRNA levels and FPN1 protein level on both days 21 and 28 than those fed the control diet. Duodenal DMT1 mRNA and protein levels were higher (P < 0.05) in OM and OS groups than in OW and MnSO4 groups on day 28. The mRNA levels of amino acid transporters [b0, +-type amino acid transporter 1 (B0AT1) and excitatory amino acid transporter 3 (EAAT3)] were higher (P < 0.0005), and peptide transporter 1 was lower (P < 0.04) in the ileum than in the duodenum and jejunum; however, Mn source did not affect (P > 0.05) mRNA levels of amino acid and peptide transporters in the small intestine of broilers. The results from the present study indicate that both DMT1 and FPN1 facilitated Mn absorption, however, the amino acid and peptide transporters might not be involved in the transport of the organic Mn chelates; organic Mn chelates with moderate and strong chelation strength, especially strong chelation strength, showed higher Mn absorption possibly due to enhanced DMT1 expression in the duodenum of broilers.
一项实验旨在研究锰（Mn）源对肉鸡小肠中 Mn 吸收以及 Mn、氨基酸和肽转运体表达的影响。将 320 只 15 日龄的 Arbor Acres 雄性肉鸡随机分配到 5 个处理组，每个处理组 8 个重复，每个重复 8 只鸡，并饲喂缺乏 Mn 的基础日粮或补充 110mg Mn/kg 的 MnSO4 或 3 种有机 Mn 螯合物中的 1 种的基础日粮，试验期为 14d。与对照组相比，补充 Mn 组的血浆 Mn 含量在第 28 天更高（P＜0.03），OS 组高于 OM 组，OM 组高于 OW 和 MnSO4 组。饲喂补充 Mn 日粮的肉鸡十二指肠二价金属转运蛋白 1（DMT1）和铁蛋白 1（FPN1）mRNA 水平和 FPN1 蛋白水平在第 21 天和第 28 天均高于饲喂基础日粮的肉鸡（P＜0.02）。与 OW 和 MnSO4 组相比，OM 和 OS 组的肉鸡在第 28 天十二指肠 DMT1 mRNA 和蛋白水平更高（P＜0.05）。与空肠和回肠相比，肉鸡的回肠中氨基酸转运体（B0，+型氨基酸转运体 1（B0AT1）和兴奋性氨基酸转运体 3（EAAT3））的 mRNA 水平更高（P＜0.0005），肽转运体 1 的 mRNA 水平更低（P＜0.04）；然而，Mn 源并未影响肉鸡小肠中氨基酸和肽转运体的 mRNA 水平（P＞0.05）。本研究结果表明，DMT1 和 FPN1 均促进了 Mn 的吸收，然而，氨基酸和肽转运体可能不参与有机 Mn 螯合物的转运；具有中等和强螯合强度的有机 Mn 螯合物，特别是强螯合强度的有机 Mn 螯合物，可能由于在肉鸡十二指肠中增强了 DMT1 的表达，从而提高了 Mn 的吸收。
