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
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. Source