Nicotinic Acid Treatment of Bovine Ketosis II. Effects on long-Chain Fatty Acid Compositions of Plasma Lipid Fractions

Abstract

Long chain fatty acid compositions of triglycerides (TG), nonesterified fatty acids (NEFA), cholesterol esters (CE), and phospholipids (PL) were examined from seven normal cows, six subclinically ketotic cows, and seven clinically ketotic cows. Ketotic cows were treated with 160 g nicotinic acid orally in four 40-g doses at 2-hr intervals. Ketosis was characterized by elevated percentages of C16:0 in TG and PL and elevated C18:1 percentages in all lipid fractions while C18:0 percentages were depressed in all lipid fractions. Rebound effects of nicotinic acid, noted 2 days after treatment, included inceased percentages of C18:1 in TG and NEFA fatty acids, indicating accelerated lipid mobilization. Decreasing percentages of C18:1 in TG and NEFA after Day 2 indicated the return to normal was associated with decreasing adipose mobilization. Triglyceride C18:0 was selectively taken up by the mammary gland under all condition, while NEFA C18:1 was selectively taken up only during periods of excess adipose mobilization. Following nicotinic acid treatment of ketosis, milk fat C14:0 and C16:0 percentages rose while percentages of C18:1 fell. © 1972, American Dairy Science Association. All rights reserved.