Structural and biophysical characterization of the major proteins from the seminal plasma of Dorper rams.

Pregnancy rates using frozen semen from rams are higher than for horses. One of the factors that positively influences this effect is the composition of low-molecular-weight proteins from seminal plasma, since the amounts of these proteins are much lower in horses. The aim of this work was to purify the major protein components from ram seminal plasma for structural and biophysical characterization. First, the ram semen was collected and the plasma separated by centrifugation. The protein fractions were isolated by gel filtration chromatography, analyzed by circular dichroism spectroscopy and the amino acid sequence identified by mass spectrometry (LC-MSE), the results of which were used to model the protein structure by bioinformatics techniques. This protein was identified by LC-MSE as a spermadhesin, being an unglycosylated monomer with Tm = 69.3 °C and ΔHm= 371 kJ mol-1 at pH 7.0. This work describes for the first time the structural characterization of a spermadhesin from seminal plasma of Dorper rams.

Inclusion of propolis in rabbit diets and semen characteristics / Inclusão de própolis na dieta de coelhos e características do sêmen / Inclusión de propóleos en la dieta de conejos y características del semen

This experiment was carried out with the objective of evaluating different levels of powder propolis in rabbit diets and their effect on semen characteristics. A total of 36 New Zealand White male rabbits were used, randomly distributed into six groups, corresponding to six propolis levels (0, 0.25, 0.50, 0.75, 1.0 and 1.25 g propolis/kg of ration). Semen was collected twice a week, using an artificial vagina. Semen volume, progressive spermatic motility, spermatic vigor, spermatic concentration and spermatic morphology were analyzed. General linear models were used for statistical analysis. The inclusion of powder propolis in the diet increased normal spermatozoa percentage and reduced spermatozoa abnormalities. The powder propolis did not affect the progressive spermatic motility, spermatic vigor or spermatic concentration. The values were considered normal for rabbits. However, a small reduction in semen volume was observed, without any negative effect on the other semen characteristics evaluated. Thus, it is possible to observe better semen quality with the inclusion of 1.25 g powder propolis/kg in the diet for reproducer rabbits...

Este experimento foi realizado com o objetivo de avaliar a influência de diferentes níveis de própolis em pó na ração de coelhos sobre as características do sêmen. Utilizaram-se 36 coelhos machos, adultos, Nova Zelândia Brancos, divididos aleatoriamente em seis grupos, consumindo cinco níveis de própolis (0; 0,25; 0,50; 0,75; 1,0 e 1,25 g de própolis/kg de ração). Coletou-se sêmen duas vezes por semana, utilizando vagina artificial. Verificou-se o volume, a motilidade espermática progressiva, o vigor espermático, a concentração espermática e a morfologia espermática. As análises estatísticas foram realizadas utilizando os modelos lineares generalizados. A adição da própolis na ração elevou a porcentagem de espermatozóides normais e reduziu os anormais. Todavia, foi observada uma pequena redução no volume do sêmen com o aumento do nível de própolis na dieta, sem afetar as demais características do sêmen. A motilidade progressiva, vigor espermático e concentração espermática não foram influenciados pelos diferentes níveis de própolis, valores considerados normais para coelhos. Conclui-se que a melhor qualidade do sêmen de coelhos reprodutores ocorreu com a adição de 1,25 g de própolis/kg de ração...

Este experimento se llevó a cabo para evaluar la influencia de diferentes niveles de polvo de propóleos en la dieta de conejos, bajo las características del semen. Se utilizó 36 conejos machos, adultos, Nueva Zelanda Blancos, divididos al azar en seis grupos, consumiendo cinco niveles de propóleos (0; 0,25; 0,50; 0,75; 1,0 y 1,25g de propóleos/kg en el alimento). Se recogió semen dos veces a la semana, utilizando vagina artificial. Se encontró el volumen, motilidad espermática progresiva, el vigor de espermático, la concentración espermática y la morfología espermática. Los análisis estadísticos se realizaron utilizando modelos lineales generales. La adición de propóleos en la dieta aumentó el porcentaje de espermatozoides normales y redujo los anormales. Sin embargo, se ha observado una pequeña reducción en el volumen del semen con el aumento de propóleos en la dieta, sin afectar las demás características del semen. La motilidad progresiva, vigor espermático y concentración de espermatozoides no se vieron afectados por los diferentes niveles de propóleos, valores considerados normales para conejos. Se concluye que la mejor calidad del semen de conejos reproductores ocurrió con la adición de 1,25g de propóleos / kg en el alimento...

Freezing injuries in the embryos of Piaractus mesopotamicus.

Cryopreservation of mammal embryos has been technically feasible for many years, but morphological injuries still persist in fish embryos during cryopreservation. Thus, the objective of the present study was to describe these freezing injuries in Piaractus mesopotamicus embryos. Two hundred and twenty-five embryos were collected at the post-gastrula stage and assigned into four treatments of sucrose at 8.5, 17.0, 25.0 or 34.0% plus 9.0% methanol. The control was prepared with distilled water only. The gradual decrease in the temperature was 0.5°C/min. After the seeding stage, the fish embryos were stored in liquid nitrogen at -33°C. Thereafter, they were thawed for evaluating per cent hatching, and the samples collected from every treatment were submitted to scanning electron microscopy for morphological analysis. The micrographic images showed that there was substantial alterations in embryo morphology under the highest concentrations of sucrose. These solutions did not prevent the formation of ice crystals, which lead to deformities and killed the embryos, but the observed reduced level of morphological structure in these embryos when treated with 17.0% sucrose plus 9.0% methanol is a compelling argument for additional studies.