Efecto de la L-carnitina en la criopreservación del semen de ovino.

Abstract

The objective of this study was to determine the effect of the addition of L carnitine in the cryopreservation of sheep semen, on microscopic seminal parameters after thawing. Twelve ejaculates from two merino sheep were used using the artificial vagina method, which presented an average volume of 1.3 + 0.40mL, whitish color, creamy appearance, pH of 6.6 + 0.46, initial concentration 3392, 5 ± 370.19 x 106 / ml progressive individual motility 89.6 + 5.82% and a mass motility around grade 4.7 + 0.45. Subsequently, each ejaculate was diluted with four treatments: T1 (Triladyl + L-carnitine), T2 (Triladyl), T3 (Andromed + L-carnitine) and T4 (Andromed), the diluted semen was slowly cooled to 5 ° C at its Once stored in 0.25mL straws and cryopreserved in liquid nitrogen. The frozen straws were individually thawed at 37 ° C for 60 seconds in a water bath, for the microscopic evaluation of the sperm. The results obtained after thawing, for progressive individual motility (MIP) were 76.3 ± 8.56%, 76.3 ± 12.99%, 5.2 ± 4.37% and 4.2 + 2.98% respectively. , in which it was determined that the frozen samples with the T1 and T2 treatment regardless of whether or not L-carnitine was added to them were statistically superior to T3 and T4. For vitality, 35.57 ± 11.60% were obtained for T1, 40.92 ± 13.55% for T2, 5.47 ± 5.74% for T3 and 4.09 ± 4.03% for T4, in it can be seen that in the first two treatments they statistically exceed frozen samples with T3 and T4. Regarding the amount of abnormalities, it follows the same trend as the previous results, where 9.54 ± 7.91% T1 and 8.14 ± 4.08% T2 have a lower percentage of abnormal sperm with respect to the other two treatments. When analyzing the sperm membranes, it was established that the addition of L-carnitinca in the treatments did not present an increase in the amount of sperm with the integral membrane. However, the treatment T1 with 32.31 ± 7.60% and T2 with 31.27 ± 6.70%, had a greater quantity of sperm with the integral membranes, with respect to T3 with 5.46 ± 3.52% and T4 with 4.40 ± 3.14%. In conclusion, the addition of L-carnitine as an antioxidant in the cryopreservation of sheep semen under our study conditions did not have benefits in the spermatozoa in any of the parameters studied. Keywords: L-carnitine, Andromet, Triladyl, Cryopreservation, sperm, sheep.