Summary
Niacin (nicotinic acid) can suppress lipolysis, but responses to dietary niacin have been inconsistent
in cattle. A widely used commercial feed additive, niacin is thought to reduce heat
stress and decrease postpartum plasma nonesterified fatty acid (NEFA) concentration. Raw
niacin has poor stability in the rumen, however, and it is estimated that only 5% is bioavailable.
Recently, an encapsulated niacin (EN) product with an estimated 40% bioavailability became
commercially available, but its effects on health and metabolism in transition cows have not
been tested previously. Twenty-two Holstein cows were used in a study beginning 21 days
before expected calving; cows were assigned to the EN treatment (24 g/day) or control group
until 21 days postpartum. Results showed that EN decreased peak plasma NEFA and ketone
concentrations after calving but also caused a 9 lb/day decrease in dry matter intake during the
final 4 days before calving in multiparous cows. These results indicate that a high dose of EN
can decrease postpartum plasma NEFA and ketones but also may decrease prepartum dry
matter intake.
Introduction
Use of