Leonardo Franco Martins

Uso de própolis e ácido ascórbico na criopreservação do sêmen caprino

The objectives of this study were to verify whether propolis and ascorbic acid have an effect on plasmatic membrane integrity of goat spermatozoa and investigate the potential of these antioxidants in the use of goats spermatozoa cryopreservation extenders. Five adult boars were used of the Alpine (n = 2) and Saanen (n = 3) breeds. After semen collection, the evaluation consisted of the physical and morphological exam, live and dead cells (supravital test) and hyposmotic swelling test. Afterwards, the fresh semen was diluted with the Bioxcell® extender (control); Bioxcell® + 0.25% freeze dried propolis extract); Bioxcell® + 0.5% freeze dried propolis extract); Bioxcell® + 0.05% ascorbic acid) or Bioxcell® + 0.25% ascorbic acid). After final dilutions, the sperm motility and vigor were assessed obtained in each extender, and then the semen was sealed, cooled and frozen. In fresh semen, the physical and morphological aspects and the results of the supravital test and hyposmotic swelling test did not differ between animals or breeds. The general means of the sperm motility and vigor, supravital test and hyposmotic swelling test obtained immediately after thawing and after three hours of heat resistence test were different, so that the extender with ascorbic acid and the control were similar and higher than the extenders containing propolis. The ascorbic acid maintained the structural integrity of the spermatozoa membrane during the cryopreservation process and its viability after the heat resistance test, and may be an alternative in extender composition for cryopreservation of goat semen; the propolis was not effective in maintaining sperm integrity and viability after thawing and was toxic to spermatozoa at concentrations of 0.25 and 0.5%.

Avaliação espermática e da concentração de proteínas solúveis no plasma seminal de bodes da raça Alpina em regime de monta controlada

Foram estudadas as relacoes entre a concentracao de proteinas soluveis do plasma seminal, o teste hipoosmotico, a analise fisica e morfologica do semen e o desempenho reprodutivo de bodes da raca Alpina em regime de monta controlada. O experimento foi realizado durante os meses de fevereiro a abril de 2001. Foram realizadas 40 coletas de semen em quatro reprodutores adultos em regime de monta controlada. Em todas as coletas, alem do exame fisico e morfologico do semen, foram realizados os testes hipoosmoticos, isoosmoticos e a determinacao da concentracao de proteinas soluveis do plasma seminal. Foi detectada diferenca entre os bodes na concentracao de proteinas soluveis do plasma seminal, mas nao houve diferenca no teste hipoosmotico e no numero de coberturas por prenhez. O teste hipoosmotico pode ser uma importante ferramenta para a avaliacao de semen caprino, mas a concentracao de proteinas soluveis do plasma seminal nao pode ser utilizada como parâmetro para predizer a qualidade seminal e a fertilidade de bodes da raca Alpina utilizados em regime de monta natural.

Correlation between hypoosmotic swelling test and breeding soundness evaluation of adult Nelore bulls

This study aimed at evaluating the relationship between physical and morphological semen features with the hypoosmotic swelling (HOS) test in raw semen of adult Nelore bulls classified as sound and unsound for breeding. Two hundred and six Nelore bulls aging from 3 to 10 years of age were subjected to breeding soundness examination. After physical and morphological semen examination, HOS test was done. After the breeding soundness examination, 94.2% of the bulls were classified as sound for breeding. There was no difference between the average scrotal circumference of bulls classified as sound and unsound for breeding (P>0.05), but there was difference between all semen physical and morphological aspects of bulls classified as sound and unsound for breeding (P>0.05), and no difference resulted in the mean percentage of reactive spermatozoa to HOS test results both for sound (38.4±17.9) and unsound animals (39.5±16.4; P>0.05), with no Pearson correlation between the HOS test and variables. According to these results HOS test can not be used alone to predict the reproductive potential of adult Nelore bulls.