Effects of Dietary Supplements of Folic Acid and Vitamin B12 on Metabolism of Dairy Cows in Early Lactation

Abstract

The present experiment was undertaken to determine the effects of dietary supplements of folic acid and vitamin B12 given from 3 wk before to 8 wk after calving on lactational performance and metabolism of 24 multiparous Holstein cows assigned to 6 blocks of 4 cows each according to their previous milk production. Supplementary folic acid at 0 or 2.6 g/d and vitamin B12 at 0 or 0.5 g/d were used in a 2 x 2 factorial arrangement. Supplementary folic acid increased milk production from 38.0 +/- 0.9 to 41.4 +/- 1.0 kg/d and milk crude protein yield from 1.17 +/- 0.02 to 1.25 +/- 0.03 kg/d. It also increased plasma Gly, Ser, Thr, and total sulfur AA, decreased Asp, and tended to increase plasma Met. Supplementary B12 decreased milk urea N, plasma Ile, and Leu and tended to decrease Val but increased homocysteine, Cys, and total sulfur AA. Liver concentration of phospholipids was higher in cows fed supplementary B12. Plasma and liver concentrations of folates and B12 were increased by their respective supplements, but the increase in plasma folates and plasma and liver B12 was smaller for cows fed the 2 vitamins together. In cows fed folic acid supplements, supplementary B12 increased plasma glucose and alanine, tended to decrease plasma biotin, and decreased Km of the methylmalonyl-coenzyme A mutase in hepatic tissues following addition of deoxyadenosylcobalamin, whereas it had no effect when cows were not fed folic acid supplements. There was no treatment effect on plasma nonesterified fatty acids as well as specific activity and gene expression of Met synthase and methylmalonyl-coenzyme A mutase in the liver. Ingestion of folic acid supplements by cows fed no supplementary B12 increased total lipid and triacylglycerols in liver, whereas these supplements had no effect in cows supplemented with B12. The increases in milk and milk protein yields due to folic acid supplements did not seem to be dependent on the vitamin B12 supply. However, when vitamin B12 was given in combination with folic acid, utilization of the 2 vitamins seems to be increased, probably more so in extrahepatic tissues. Metabolic efficiency seems also to be improved as suggested by similar lactational performance and dry matter intake for cows fed supplementary folic acid but increased plasma glucose and decreased hepatic lipids in cows fed folic acid and vitamin B12 together.

Effects of rumen-protected folic acid on ruminal fermentation, microbial enzyme activity, cellulolytic bacteria and urinary excretion of purine derivatives in growing beef steers

“…However, literatures have demonstrated that folic acid administered by intramuscular injections or dietary supplementation improved the growth of weaned dairy calves (Petitclerc et al, 1999) and heifers (Dumoulin et al, 1991) and increased milk yields and milk component production in dairy cows (Girard and Matte, 1998;Graulet et al, 2007;Li et al, 2016). Furthermore, some literatures reported that the synthesis of folic acid in the rumen ranged from 16.5 to 21.0 mg/d in dairy cows (Santschi et al, 2005;Schwab et al, 2006), while the estimated folic acid requirement of a cow with 650 kg BW and 35 kg of fat-corrected milk yield was 35 mg/d (NRC, 2001).…”

Supplementing lactating dairy cows with a vitamin B12 precursor, 5,6-dimethylbenzimidazole, increases the apparent ruminal synthesis of vitamin B12

“…Increasing vitamin B 12 supply of dairy cows with an adequate folate status has been reported to improve efficiency of energy metabolism in early lactation Graulet et al, 2007;Preynat et al, 2009). However, as much as 80% of a dietary supplement of cyanocobalamin, the synthetic form of vitamin B 12 , was catabolized in the rumen (Girard et al, 2009b).…”

Effects of dietary nitrogen levels and carbohydrate sources on apparent ruminal synthesis of some B vitamins in dairy cows

“…Even though they are required in small amounts, B vitamins play an essential role as they act as cofactors or coenzymes in the metabolism of carbohydrates, lipids, proteins, and nucleic acids (Combs, 2012). Several researchers have shown that B-vitamin supplements can improve milk yield, composition, and metabolic efficiency in highproducing dairy cows (Jaster and Ward, 1990;Girard and Matte, 1998;Shaver and Bal, 2000;Graulet et al, 2007). However, the response to these dietary supplements is highly variable and one of the major reasons is because the amounts of vitamins provided by the basal diet and the synthesis in the rumen are unknown.…”