Carnitine status and lipid utilization in neonatal piglets fed diets low in carnitine

Forty-eight newborn piglets were assigned to dietary regimens to examine carnitine status and lipid utilization by piglets nursing sows (Diet 1), fed a high-carnitine (1507 mumol carnitine/kg dry matter) casein-whey formula (Diet 2) or fed a low-carnitine (35 mumol carnitine/kg dry matter) egg white protein formula (Diet 3). Four piglets were killed at birth, and four per dietary group were killed at 3, 7, 14 and 21 d of age. Piglets fed Diet 3 had lower (P less than 0.01) carnitine in plasma and liver by d 7 and carnitine remained lower to d 21. Heart carnitine tended to be lower in piglets fed Diet 3, but the differences were not significant. Longissimus muscle carnitine was not affected. In vitro palmitate oxidation was lower (P less than 0.05) on d 7 in the liver from piglets fed Diet 3 but not on d 3, 14 and 21. Low dietary carnitine did not affect in vitro liver beta-hydroxybutyrate production or oxidation of palmitate by longissimus muscle. Plasma glucose and nonesterified fatty acids were higher (P less than 0.05) in piglets nursing sows than those fed Diets 2 or 3. Piglets receiving Diet 3 had reduced carnitine in plasma and certain tissues, and liver lipid oxidation was depressed on d 7 of age, compared with those receiving the other two diets. Feeding the low carnitine diet did not alter glucose status or plasma lipids and ketones.