L-carnitine supplementation in breeding pigeons: impact on zootechnical performance and carnitine metabolism Geert P.J. Janssens, Myriam Hesta, Valerie Debal, Jacques Debraekeleer and Roland O.M. De Wilde Reprod. Nutr. Dev., 40 6 (2000) 535-548 DOI: 10.1051/rnd:2000135