Two lactation trials were undertaken to evaluate the effect of a niacin
supplement on milk production and 'the physiological symptoms of ketosis. Blood
ketone and non-esterified fatty acid levels were lower and blood glucose
concentrations higher in niacin-supplemented cows. These trends were exhibited
regardless of whether supplementation began 2 wk prepartum or immediately after
calving. A 6 g daily dose was found to be of equal or higher benefit than a 12 g
supplement. Cows gi ven niacin consistently produced more milk than controls,
though the difference was small.
