Avaliação do sêmen fresco e criopreservado de garanhões suplementados com antioxidantes e compostos naturais

Abstract

Sêmen cryopreservation before the period of natural mounting can optimize the use of biotechnology during the reproductive period. However, stallions can be improved as far as supplementation (supp) with antioxidants and natural compounds, a specialty out of the reproductive season. Thus, the diet of four Quarter Horse Stallions was supplemented during 75 days by a commercial product: folic acid, Beta Carotene, L- Carnitine, milled whole flaxseed, Vitamin C and E. Experimental period initiated with sêmen being collected for basal biological leveling (exhaustion of sperm reserves), followed by sêmen collection for criopreservation (phase 1). After this period, the supp was initiated and at its finalization, a new phase was performed by basal biological leveling (n= 6 collection x 4= 24) and sêmen collection for criopreservation (n=24) successively. Despite the fact that 96 ejaculates were obtained, only 24 pre and post supp were cryopreserved and compared after thawing. Fresh sêmen variables were analyzed immediately after collection and submitted to Box Plot representation, without significant differences. After thawing sêmen straws, previously processes in respective moments pre and post supp, were then submitted to CASA (Computerized assisted sperm analysis) and kinetics variables were determined. Other variables as: sperm plasma membrane integrity were assessed by fluorescent probes and morphology by phase contrast microscopy, but no significant differences were found. Criopreserved sêmen data was submitted to PROC MIX, from SAS; and resulted in significant differences as far as variables from kinetics by CASA: motility, velocity, movement amplitude ( superior for pre vs post supp) and linear and rectilinear ( superior at post versus pre supp).