Supplementation of sows with L-carnitine during pregnancy and lactation improves growth of the piglets during the suckling period through increased milk production

Recent studies showed that piglets of sows fed diets supplemented with L-carnitine grow faster during the suckling period than piglets of control sows fed diets without L-carnitine. This study was undertaken to investigate the effect of L-carnitine supplementation in sows on milk production and milk constituents. An experiment was performed in which two groups of 20 gilts each were fed diets with or without supplemental L-carnitine during pregnancy (0 vs. 125 mg L-carnitine daily/sow) and lactation (0 vs. 250 mg L-carnitine daily/sow). The experiment was continued over two reproductive cycles. L-carnitine-treated sows had larger litters (P<0.01) and higher litter weights (P<0.05) than control sows. Piglets of L-carnitine-treated sows had lower birth weights (P<0.05) but grew faster during the suckling period (P<0.01) and were heavier (P<0.05) at weaning than piglets of control sows. L-carnitine-treated sows had higher milk yields on d 11 and 18 of lactation than control sows (P<0.05). Milk of L-carnitine-treated sows had higher concentrations of total and free carnitine than milk of control sows (P<0.001); concentrations of fat, protein and lactose and the amounts of gross energy in the milk did not differ between the two groups of sows. The amounts of protein (P<0.05) and lactose (P<0.05) were higher in L-carnitine-treated sows than in control sows; the amount of energy secreted with the milk tended to be higher in carnitine-treated sows than in control sows (P<0.10). The study suggests that piglets of carnitine-treated sows grow faster during the suckling period than those of control sows because they ingest more nutrients and energy with the milk.