Efeito da gelatina na refrigeração à 50C do sêmen ovino

Abstract

Under refrigeration, the spermatic cell survivability depends upon its spatial orientation in the extender medium and the agglutination or sedimentation of these cells should not occur. In more solid extenders like the one supplemented with gelatin, the spatial disposition can be improved, and also the metabolic demand is lower by the reduced motility provoked by more solid medium. The main aim of this work was evaluate the qualitative effect provoked by addition of gelatina to the ram semen extender stored at 5ºC. There were used 8 rams being accomplished 4 semen collections for each, totalizing 32 ejaculates. Two extenders were used in this study, E1 (whole milk 10%, 0.2g D-Glugose, 50 mg streptomycin and 100 ml of mili Q water), and the E2 (E1 plus 1.5% of gelatin). There were evaluated motility, cell morphology, DNA, membrane and acrosome integrity, during the period of 0h, 24hs, 48hs, and 72 hours of storage under refrigeration at 5°C. During the first 48hs of storage the spermatic motility remained the same in the E1 and E2, however, at 72hs the E2 (51,9%) was more efficient in the maintenance of the motility parameters (P<0.05) than the E1 (31,1%). The acrosome integrity was similar in both extenders at 0h, 24hs and 48h of storages, but at 72hs the E2 showed the best result (P<0.05) in this parameter (E1=42,9% and E2=66,9%). The viability, morphology and membrane and DNA integrity had not shown statistical difference comparing the treatments (P>0.05). With the results there is possible to conclude that the addition of gelatin to the extender increased the motility and acrosome integrity in ram semen stored at 5ºC, increasing through this the possibility of extending the storage time under refrigeration of the semen doses to more than 24hs.