Nicotinic Acid Loading of Normal Cows: Effects on Blood Metabolites and Excretory Forms

Abstract

Oral administration of 160 g nicotinic acid in 4 doses to normally fed, lactating cows resulted in declines followed by rebound elevations in plasma nonesterified fatty acids. Urine volume increased 8 to 16 hr after nicotinic acid administration. Urinary N′-methylnicotinamide and nicotinamide excretion accounted for only 6.5 g of the 160 g nicotinic acid given. The main excretory form during the 56-hr sampling was the unaltered nicotinic acid which accounted for 53.2 g of the administered dose. © 1972, American Dairy Science Association. All rights reserved.