Just like humans, cows also need B-vitamins to carry out metabolic processes. These vitamins are a result of rumen microbe function in ruminants. Most of the time, these vitamins aren’t included in the makeup of a cow’s ration because we automatically assume that the rumen microbes will do the work for us, giving the animal its required amount. In an Ohio State Buckeye Dairy News, animal science assistant professor Kirby Krogstad suggested that adding extra B-vitamins to a dairy cow’s ration may be helpful to see a boost in milk production.

The B-vitamin complex includes 8 vitamins: thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folate, and cobalamin (B-12). These vitamins are powerful, so rumen microbes supply the cow with very small amounts. “For a cow eating 55 pounds per day of dry matter, it will be supplied between 1.3 and 6.6 grams per day of total B-vitamins,” Krogstad said.

“Generally, to allow more B-vitamins to exit the rumen and get used by the cow, adding rumen fermentable carbohydrates will do the trick. This becomes an exception when it comes to vitamin B-12, as its amounts are reduced when additional starch is incorporated into the diet,” he added. “For example, a 10% increase in dietary starch would increase thiamin by 3%, riboflavin by 5%, and folate by 6%, while reducing cobalamin by 2%.”

Not only are these vitamins beneficial to cows, but they also supplement a few of our vitamin needs as well. In fact, cows release B-vitamins into their milk, and one cup of milk can provide us with 10% of our thiamin needs, 40% of our riboflavin needs, 1% of our niacin needs, 20% of our pantothenic acid needs, 7% of our pyridoxine needs, 4% of folates, and 50% of our cobalamin needs. This is considered a win-win for both parties.

Additional starch results in the production of more B-vitamins, with the exception of cobalamin. It is important to note that cobalamin levels may drop if starch is added into the diet. A dairy cow’s diet has the ability to affect the amount of B-vitamins that exit the rumen each day. As we think about the importance of these B-vitamins, consider that they are not only valuable for the cow, but they are necessary for humans as well.