Use of propolis and ascorbic acid on goat semen cryopreservation / Uso da própolis e do ácido ascórbico na criopreservação do sêmen caprino

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The objectives of this study were to verify if the propolis and ascorbic acid contain effect on plasmatic membrane integrity of goats spermatozoa as well as investigate the potential of these antioxidants on the use of goats spermatozoa cryopreservation extenders. Semen from five adults goats were used, totalizing 5 semen samples for each one. After semen collection, the evaluation consisted of physical and morphological exam, live and dead cells (supravital test) and hyposmotic swelling test. Afterwards, the fresh semen was diluted, homogenized, divided on 5 equal parts and centrifuged. The spermatozoa pellet was raised with respective treatment: T1 (BIOXCELL - CONTROL); T2 (BIOXCELL + 0,25% of propolis extract); T3 (BIOXCELL + 0,5% of propolis extract); T4 (BIOXCELL + 0,05% of ascorbic acid); e T5 (BIOXCELL + 0,25% of ascorbic acid). After final dilutions, it was evaluated the sperm motility and vigor on each treatment, and posterior seal. The straws were cooled at 4 - 5 C during 35 minutes in a plastic container containing methyl alcohol and 25 minutes out of container. The pre-freezing was done in liquid nitrogen vapour, during 14 minutes. Then, the straws were immersed in nitrogen. The thawing of the samples was made by immersion of the straws in a 37 C water-bath for 30 minutes to evaluate the sperm motility and vigor, supravital test, hyposmotic swelling test and thermoresistence test. In fresh semen, the physical and morphological aspects, supravital test and hyposmotic swelling test not differ (P>0,05) between animals and between races. There was no correlation of appearance and whirlpool with other variables. There was mean and negative correlation (r = -0,46) between the volume and hyposmotic swelling test. The sperm motility showed average and positive correlation with sperm vigor (r = 0,52) and supravital test (r = 0,55). There was high and positive correlation (r = 0,73 and 0, 69) between major and minor defects sperm with defects totals. There was mean and negative correlation (r = -0,40) between major defects sperm and hyposmotic swelling test, not being seen with the minor defects. The average sperm motility of the diluted semen (pre-cooling) of all treatments, showed no difference between them (P>0,05), however, the averages of sperm vigor of diluted semen showed difference (P<0,05) among treatments, where the T1 and T3 were different from T4 and equals to T2 and T5. The general average of motility and vigor sperm on treatments immediately after thawing and after three hours of thermoresistence test differed among themselves (P<0,05), where the T4, T5 and T1 were similar and higher than T2 and T3. The general average values observed in supravital test and hyposmotic swelling test post-thawing differed (P<0,05) among treatments, in which the T4, T5 and T1 were similar and higher than T2 and T3. The values observed on supravital test showed high and positive correlation with sperm motility in all treatments. In T1, T4 and T5 had high and positive correlation (r = 0,63; r = 0,64; r = 0,71; respectively) between the values in supravital test and hyposmotic test. The values observed in the hyposmotic test and sperm motility showed high and positive correlation in T1 (r = 0,78) and T5 (r = 0,65) and correlation mean and positive in T4 (r = 0,44). Both at the time of thawing (0 hour) as the end of the thermoresistence test (3 hours), the supravital test and sperm motility showed no correlation with the motility sperm of treatments this study. But at the time of thawing, the average values observed in hyposmotic test of fresh semen showed average and positive correlation with sperm motility of T1 and T2, and high and positive correlation with the T5 motility sperm. Similarly, at 3 hours of thermoresistence test, there was average and positive correlation with sperm motility of T1, T4 and T5. It was concluded that: the ascorbic acid maintained structure integrity of the spermatozoa membrane during cryopreservation process as well as its viability after thermoresistence test, and may be an alternative in the composition of extenders for cryopreservation of semen goats; the propolis was not effective in maintaining the integrity and viability sperm after thawing, showing to be toxic to spermatozoa at concentrations of 0,25 and 0,5%; and the hyposmotic test in fresh semen was effective in predicting the semen freeze, as well as, its viability in the end of the thermoresistence test of three hours.

ASSUNTO(S)

criopreservação propolis própolis reproducao animal semen cryopreservation sêmen

ACESSO AO ARTIGO

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