Body composition, muscle fibre characteristics and postnatal growth capacity of pigs born from sows supplemented with L-carnitine

Recently, it has been shown that supplementation of sows with L-carnitine increases their plasma concentrations of insulin-like growth factor (IGF)-I, and it has been hypothesized that this may stimulate fetal myogenesis. This study was performed to investigate whether piglets of sows supplemented with L-carnitine differ in muscle fibre characteristics, chemical body composition and postnatal growth capability from pigs of control sows. Muscle fibre characteristics and chemical body composition were determined at weaning in 21 piglets of control sows and 21 piglets of sows treated with L-carnitine with similar body weights; postnatal growth capability was determined from weaning until slaughter at a body weight of 118 kg in 80 pigs of control sows and 80 pigs of sows treated with L-camitine which had also similar body weights at weaning. Piglets of sows supplemented with L-carnitine did not differ in number, area, diameter and type (percentages of slow twitch oxidative + fast twitch oxidative fibres, and fast twitch glycolytic fibres) of muscle fibres in m. longissimus dorsi and m. semitendinosus and in chermical body composition (concentrations of dry matter, crude protein, crude fat) from piglets of control sows. Postnatal growth capability (body weight gains, feed conversion ratio) from weaning to slaughter as well as carcass composition (carcass yield, meat thickness, fat thickness) was also not different between pigs of sows treated with L-carnitine and pigs of control sows. In conclusion, data of this study do not support the hypothesis that L-carnitine supplementation of sows during pregnancy enhances fetal muscle fibre development and increases postnatal growth capability of the offspring.