Do extra vitamins help? Today there are fewer cows producing more milk. Cows have become more efficient.

The vitamins A, D, and E are routinely supplemented to lactating cows. In the past, B vitamins, for example, biotin, choline and niacin, were thought that microbes in the rumen and their abundance in the feedstuffs would provide all the B vitamins needed by the cow. As the lactating cow produces more milk, the supplementation of biotin, choline and niacin have been found to show improvement in milk production, hoof hardness and reproduction. Even though clinical deficiencies of B vitamins are rare in dairy cows, interest in B vitamins has increased in the past few years.

A dietary requirement for biotin has not been established for dairy cows. Feeding biotin for two to three months to the dairy cow may reduce hoof lesions. Six months of adding biotin may be necessary to reduce clinical lameness. The most common level of biotin supplementation is 20 milligrams per head per day. Milk production increases from supplemental biotin are less consistent than hoof hardness; the increase in milk production appears rapidly after adding biotin. Responses in milk production have been observed in high-producing cows (90 pounds) but not in low-producing cows (50 pounds). Adding of biotin to the cow’s diet looks favorable, but additional evaluation is needed.

Recently there has been a lot of interest in feeding choline to dairy cows. Choline does not fit the definition of a vitamin. The amount of choline added to the diet of a cow is in grams, not milligrams. Choline must be protected to bypass the rumen; otherwise it is degraded in the rumen. Adding choline to the lactating cow diet showed a numerical increase in milk production in 11 out of 12 trials. The median increase from choline supplementation was about five pounds.

In addition to measuring milk and milk solids production, one should evaluate cow health and reproductive performance. For example, a decrease in the incidence of ketosis in transition cows has been observed in rumen-protected choline fed to dairy cows. The amount of choline chloride fed is mostly at 15 grams per day. As much as 50 grams per head per day has been fed.


Another B vitamin, niacin (nicotinic acid or nicotinamide) has been fed to many lactating cows. In a survey of the highest producing dairy herds (data collected in 2000), niacin was the only B vitamin fed to a substantial number of herds (43 percent of the herds reported at least one group of cows was fed niacin). Biotin and choline were also fed, but they were used by less than 4 percent of the herds surveyed. Niacin is the most extensively researched B vitamin in dairy cows. Results of niacin supplementation are consistently inconsistent. Improvements in milk production or in blood parameters occur infrequently. A level of 12 grams of niacin per cow per day has been recommended for treatment and fed to early-lactation cows. Use of rumen-protected niacin supplements may prove useful.

Today we find a lactating cow that can produce large amounts of milk. Once thought as not required and available to the cow are some B vitamins. Choline, biotin, and possibly niacin might to be looked at to nutritionally supplement the lactating cow today. The form in which it is fed to the cow is also important. PD

Lawson Spicer
Nutri-Management, Inc. Animal Nutritionist

Lawson Spicer for Progressive Dairyman