A study of the acylcarnitine content of sows' colostrum, milk and newborn piglet tissues: demonstration of high amounts of isovalerylcarnitine in colostrum and milk.

As part of a project to determine if newborn piglets contain less than optimal amounts of carnitine, the carnitine and acylcarnitine content of colostrum, milk and serum of sows and of serum, liver, heart and muscle of newborn and 2-day-old piglets was measured. Colostrum contained high amounts (370 nmol/ml) total carnitine, with greater than 95% being acylated. The principal acylcarnitines (approx. 45% each) were acetyl- and isovalerylcarnitine . In contrast, serum from lactating or nonpregnant nonlactating sows and from piglets all contained primarily free carnitine and some acetylcarnitine but only traces of isovalerylcarnitine . At birth, the blood and liver of piglets contained very low amounts of total carnitine, which increased two- and fourfold, respectively, after 2 days of suckling. These data show that newborn piglet liver and blood are carnitine poor and indicate that the high levels in colostrum and milk are a source of tissue carnitine. The large amounts of acetyl- and isovalerylcarnitine in colostrum and milk might facilitate secretion of available carnitine.