Efeito de vitaminas e aminoácidos como suplementação da solução crioprotetora para a criopreservação do sêmen de tambaqui (Colossoma macropomum) / Effect of vitamins and amino acids as cryoprotectant solution supplementation for the cryopreservation of tambaqui semen (Colossoma macropomum)

ABSTRACT

Background: The addition of antioxidant substances to a cryoprotective solution can increase its protective capacity, shielding spermatozoa from the oxidative stress caused by the seminal cryopreservation process. However, there is no record of a seminal cryopreservation protocol of tambaqui (Colossoma macropomum) using antioxidants as a supplement to the cryoprotective solution. Thus, the objective of this study was to evaluate the effects of adding vitamin C, vitamin E, cysteine, and/or taurine to the seminal cryopreservation of tambaqui.Materials, Methods & Results: Pools of semen (n = 10) were diluted in cryoprotective solutions supplemented with vitamin C (T1), vitamin E (T2), vitamin C + vitamin E (T3), cysteine (T4), taurine (T5), and taurine + cysteine (T6). The control treatment (T7) was not supplemented. Diluted semen was loaded in 0.5 mL straws, frozen in a dry-shipper, stored in a cryogenic cylinder, and then thawed in a water bath (45ºC for eight seconds). The quality of fresh and cryopreserved semen was evaluated by measuring total motility, progressive motility, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity, and straightness using a computerized system of sperm analysis. Sperm membrane integrity parameters were analyzed using eosin-nigrosin staining, sperm morphology was assessed using pink bengal staining, and motility duration was measured by a digital timer. Data were analyzed using the statistical program SAS (2002) and the results were expressed as means ± standard error of the mean. The results showed that, in general, there was no significant increase in seminal quality when antioxidants were added to the cryoprotective solution. The T5 treatment promoted an increase (P 0.05) from the other treatments.[...]