Effect of dietary choline supplementation under different flavin-containing monooxygenase 3 genotypes on trimethylamine metabolism in laying hens.
To evaluate the effect of flavin-containing monooxygenase 3 (FMO3) genotype and dietary choline supplementation on trimethylamine (TMA) metabolism in HyLine Brown laying hens, a 3 × 2 two-factorial arrangement was employed with FMO3 genotypes (AA, AT, and TT) and dietary choline supplemental levels (370 and 2,960 mg/kg of diet) as main effects. At 46 wk of age, 108 hens of AT genotype and 108 hens of TT genotype were randomly allotted to one of the 2 dietary treatments, and each dietary treatment consisted of 6 replicates with 9 birds each. A total of 24 hens with AA genotype was allotted to one of the 2 dietary treatments that consisted of 6 replicates with 2 hens. Hens were fed the diet with 370 mg/kg of choline supplementation for 1 wk of adaptation followed by a 6-wk trial period. Yolk TMA concentration was increased by dietary supplemental choline at 2,960 mg/kg (P < 0.05), and TT hens showed a higher TMA content in egg yolks than that in AA and AT hens (P < 0.05). Dietary supplementation of choline at 2,960 mg/kg increased the TMA concentration of cecal chyme (P < 0.05) and serum (P < 0.05). Hepatic FMO3 mRNA levels in hens were reduced by higher choline added to the diet (P < 0.05). The TMA and methimazole oxidation rate in AA hens was higher than those in AT and TT hens (P < 0.05). A higher choline diet decreased hepatic FMO3 activity by 33.99% (P < 0.05) and 61.39% (P < 0.05) toward TMA and methimazole, respectively. These results suggest that lower hepatic FMO3 activity caused by the mutation may be responsible for the genotype difference in the TMA metabolism. Exposure to a high dosage of dietary choline increased TMA synthesis in the cecum, suppressed activity of FMO3 in liver, and consequently aggravated the burden of TMA metabolism, especially in TT hens.
Key Laboratory of Feed Biotechnology of Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
J
J
Wang
H Y
HY
Yue
Z Q
ZQ
Xia
S G
SG
Wu
H J
HJ
Zhang
F
F
Ji
L
L
Xu
G H
GH
Qi
D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002432:Cecum / Q000378:metabolism; D002645:Chickens; D002794:Choline / Q000008:administration & dosage / Q000494:pharmacology*; D004032:Diet / Q000662:veterinary*; D019587:Dietary Supplements; D004530:Egg Yolk / Q000378:metabolism; D005260:Female; D005766:Gastrointestinal Contents / Q000737:chemistry; D005786:Gene Expression Regulation; D005838:Genotype; D008744:Methylamines / Q000737:chemistry / Q000378:metabolism*; D010058:Oviposition; D010105:Oxygenases / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D008744:Methylamines; D012333:RNA, Messenger; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming); C023336:trimethylamine; D002794:Choline