Yu B.,Key Laboratory for Animal Nutrition of Disease Resistance |
Yu B.,Sichuan Agricultural University |
Yang G.,Key Laboratory for Animal Nutrition of Disease Resistance |
Yang G.,Sichuan Agricultural University |
And 4 more authors.
Frontiers of Agriculture in China | Year: 2010
The present study was conducted to evaluate the effects of different folic acid supplemental levels on growth performance, serum biochemical indicators, and hepatic folate metabolism-related gene expressions in weaned piglets. There were 160 piglets with initially average bodyweight of 7.33 kg randomly assigned to diets containing five levels of folic acid: basal diets (C), 0.5 mg·kg-1 folic acid (FS 0.5), 2.5 mg·kg-1 folic acid (FS 2.5), 5.0 mg·kg-1 folic acid (FS 5.0), or 10.0 mg·kg-1 folic acid (FS 10.0). Blood samples were collected from a subset (n = 20; 4 pigs per treatment) of the piglets on day 0, 14, and 28. Liver samples were collected from the blood-taken piglets on day 28 of the experiment. Pigs fed basal diet supplemented with 2.5 mg·kg-1 folic acid grew faster (P<0.05) and consumed more feed (P<0.01) than groups of C, FS 5.0, and FS 10.0 during the last two weeks. Dietary treatment had no effect on F/G throughout the experiment. Pigs in the FS 2.5 group showed greater concentrations of Growth Hormone (GH) (P<0.05) and Insulin-like Growth Factors (IGF-1) (P<0.01) in serum than C and FS 10.0 on day 28. RT-PCR analysis revealed that FS 0.5, FS 2.5, and FS 5.0 had a greater abundance of the mRNA encoding 5,10-methylenetetrahydrofolate reductase than C and FS 10.0 (P<0.01). The mRNA expressions of folate binding protein in FS 0.5 and FS 2.5 were upregulated compared with pigs fed with basal diet (P<0.05). These results demonstrated that folate supplemental level of 2.5 mg·kg-1 significantly enhanced the growth performance of piglets. Folic acid had an impact on folate metabolism and the homocysteine concentrations. No folate supplementation or folate supplemental level of 10 mg·kg-1 could not increase the growth performance to the greatest degree. © Higher Education Press and Springer-Verlag Berlin Heidelberg 2010.