Use of molecular biomarkers to estimate manganese requirements for broiler chickens from 22 to 42 d of age.
The present study was carried out to evaluate dietary Mn requirements of broilers from 22 to 42 d of age using molecular biomarkers. Chickens were fed a conventional basal maize-soyabean meal diet supplemented with Mn as Mn sulphate in graded concentrations of 20 mg Mn/kg from 0 to 140 mg Mn/kg of diet for 21 d (from 22 to 42 d of age). The Mn response curves were fitted for ten parameters including heart Mn-containing superoxide dismutase (MnSOD) mRNA and its protein expression levels and the DNA-binding activities of specificity protein 1 (Sp1) and activating protein-2 (AP-2). Heart MnSOD mRNA and protein expression levels showed significant quadratic responses (P<0·01), and heart MnSOD activity showed a broken-line response (P<0·01), whereas Mn content and DNA-binding activities of Sp1 and AP-2 in the heart displayed linear responses (P<0·01) to dietary Mn concentrations, respectively. The estimates of dietary Mn requirements were 101, 104 and 94 mg/kg for full expressions of MnSOD mRNA level, MnSOD protein level and MnSOD activity in the heart, respectively. Our findings indicate that heart MnSOD mRNA expression level is a more reliable indicator than heart MnSOD protein expression level and its activity for the evaluation of Mn requirement of broilers, and about 100 mg Mn/kg of diet is required for the full expression of heart MnSOD in broilers fed the conventional basal maize-soyabean meal diet from 22 to 42 d of age.
1Mineral Nutrition Research Division,Institute of Animal Science,Chinese Academy of Agricultural Sciences (CAAS),Beijing 100193,People's Republic of China.
Lin
L
Lu
1Mineral Nutrition Research Division,Institute of Animal Science,Chinese Academy of Agricultural Sciences (CAAS),Beijing 100193,People's Republic of China.
Bin
B
Chang
1Mineral Nutrition Research Division,Institute of Animal Science,Chinese Academy of Agricultural Sciences (CAAS),Beijing 100193,People's Republic of China.
Xiudong
X
Liao
2Department of Animal Science,Guangdong Ocean University,Zhanjiang 524088,People's Republic of China.
Runlian
R
Wang
1Mineral Nutrition Research Division,Institute of Animal Science,Chinese Academy of Agricultural Sciences (CAAS),Beijing 100193,People's Republic of China.
Liyang
L
Zhang
1Mineral Nutrition Research Division,Institute of Animal Science,Chinese Academy of Agricultural Sciences (CAAS),Beijing 100193,People's Republic of China.
Xugang
X
Luo
D000818:Animals; D030161:Avian Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D002645:Chickens / Q000254:growth & development / Q000502:physiology*; D002681:China; D002149:Energy Intake; D015971:Gene Expression Regulation, Enzymologic; D006321:Heart / Q000254:growth & development; D008297:Male; D008345:Manganese / Q000008:administration & dosage* / Q000032:analysis / Q000378:metabolism; D017895:Manganese Compounds / Q000008:administration & dosage; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D009751:Nutritional Requirements; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D015203:Reproducibility of Results; D016329:Sp1 Transcription Factor / Q000737:chemistry / Q000378:metabolism; D013431:Sulfates / Q000008:administration & dosage; D013482:Superoxide Dismutase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050656:Transcription Factor AP-2 / Q000737:chemistry / Q000378:metabolism; D015430:Weight Gain
D030161:Avian Proteins; D015415:Biomarkers; D017895:Manganese Compounds; D012333:RNA, Messenger; D016329:Sp1 Transcription Factor; D013431:Sulfates; D050656:Transcription Factor AP-2; D008345:Manganese; D013482:Superoxide Dismutase; C039798:manganese sulfate
 AP-2 activating protein-2;  MnSOD manganese-containing superoxide dismutase;  Sp1 specificity protein 1; Broilers; Dietary requirements; Gene expression; Manganese; Manganese-containing superoxide dismutase