Effect of L-Carnitine Supplementation on Boar Semen Quality

Jacyno E., A. Kołodziej, M. Kamyczek, M. Kawęcka, K. Dziadek, A. Pietruszka: Effect of L-Carnitine Supplementation on Boar Semen Quality. Acta Vet Brno 2007, 76: 595-600. The effect of addition of L-carnitine on boar semen quality was studied in 5 Pietrain boars at age 1.5 2.0 years. The boars received 500 mg of L-carnitine per day for 5 weeks. During this period, their ejaculates were collected once a week and evaluated for quality. The control ejaculates had been collected before the application of L-carnitine. It was found that the addition of L-carnitine to the boars’ feed had a positive effect on the quality of boar semen. The total ejaculate volume and sperm-rich fraction volume increased by 11% and 10%, respectively; the total ejaculate sperm count increased by 11.5% (P < 0.05). Also, the number of spermatozoa with major and minor morphological changes decreased and seminal plasma activity of AspAT was significantly reduced (P < 0.01). Sperm concentration and motility, as well as normal acrosome sperm percentage, did not increase considerably. The positive effect of L-carnitine on boar semen quality was observable as early as after one week of its application. L-carnitine, boars, semen, spermatozoa, seminar plasma, AspAT Carnitine occurs in the form of L-and D-isomers; however, only the L-isomer of carnitine is biologically active, while the D-isomer may even be noxious for the organism (Szilagyi 1998). L-carnitine is a natural, vitamin-like amino-acid, synthesised within the body from lysine and methionine (Vaz et al. 2002), and is very important in the metabolism of lipids. It carries long-chain fatty acids to the mitochondria for beta-oxidation, which produces energy (ATP) needed by the cells for proper functioning (Hoppel 2003; Ramsay et al. 2001). L-carnitine plays an important role in the processes of cellular detoxification, since it removes acyl-CoA from the mitochondria, excess of which has a toxic effect (ArrigoniMartelli and Caso 2001). It also protects cellular membranes against oxidative damages resulting from peroxidation of polyunsaturated fatty acids that are a component of membrane phospholipids (Kalaiselvi and Panneerselvam 1998). We can find scant information in literature regarding the positive effect that L-carnitine exerts on male reproductive processes, especially on spermatogenesis. The compound increases sperm concentration and motility in men with idiopathic asthenozoospermia (Vitali et al. 1995; Matalliotakis and Koumantakis 2000), in adult male chickens (Neuman et al. 2002), and in rats (Palmero et al. 1990). L-carnitine also has a positive effect on boar reproduction. Its concentration in epididymal plasma of the boars ranges between 200 300 nmol·mg–1 of protein; from there, L-carnitine is transported by passive diffusion to the spermatozoa (Jeulin et al. 1987). An addition of L-carnitine in the ration increases its concentration in the epididymal tubules and, consequently, in the spermatozoa (Jeulin et al. 1994). Inside a sperm cell, L-carnitine transports fatty acids to the mitochondria, where they undergo beta-oxidation leading to the generation of metabolic energy needed by the sperm cells for their progressive movement (Jeulin et al. 1987). ACTA VET. BRNO 2007, 76: 595-600; doi:10.2754/avb200776040595 Address for correspondence: Prof. dr hab. Eugenia Jacyno Department of Pig Breeding, University of Agriculture Doktora Judyma 10 str., 71-460 Szczecin, Poland Phone: (+48) 091 4541433 Fax: (+48) 091 454 16 42 E-mail: [email protected] http://www.vfu.cz/acta-vet/actavet.htm