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The effect of gossypol acetate on the fertility of boars
47-55

This study evaluated the effect of gossypol acetate, a potential antifertility compound, on semen quality and testicular histopathology of boars. Six boars were allotted into two experimental groups. Half of the animals were fed a diet that was supplemented with 2 mg of gossypol acetate per kg body weight per day for 9 weeks, control animals received a gossypol acetate-free feed. During the experimental period, semen was collected weekly from each boar and semen parameters were recorded. The animals were then euthanized, testicular samples were collected and histopathological examination of the testicular cells, as well as morphometrical analysis of the seminiferous tubules, were performed. The percentage of spermatozoa showing tail abnormalities increased significantly (P=0.017) in the semen of boars fed gossypol acetate-supplemented feed, while several other semen parameters deteriorated without showing statistical significance. Gossypol acetate supplementation also led to a decrease (P=0.042) in the number of spermatogonia in the seminiferous tubules and an increase (P=0.020) in the number of vacuoles in the seminiferous epithelium, consistent with changes seen in cases of male reproductive toxicity. In conclusion, gossypol acetate negatively affected a number of semen characteristics and also had detrimental effects on the histopathology of the testes.

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Az évszak és az azonos évszakban történt ismételt mintavételek hatása holstein tenyészbikák ejakulátumának minőségi- és mennyiségi jellemzőire
33-37

This study was carried out at the Hungarian National Artificial Insemination Centre in order to evaluate the seasonal effects on the quantitative and qualitative parameters of sperm production using sperm analyser equipment. The volume of ejaculate (VE), percentage of living sperm (PLS), spermatozoa concentration (SC), motility score (MC), percentage of motile spermatozoa (PMS), speed of movement of sperm cells (SMS) and the percentage of sperm cells moving straightforward (PSMS) were collected and observed in three seasons (summer, autumn, winter) in Holstein-Friesian breeding bulls (n = 15). The sperm collection was done for three successive weeks in every season on the same day (summer: n = 41, autumn: n=39, winter: n = 42, altogether: n = 122). The same sperm samples were measured by sperm analyser equipment (HTM version 7.0, Danvers) for PMS, SMS and PSMS. The seasonal and the number of sperm collection effects were confirmed on semen characteristics by multiple analysis of variance (two ways MANOVA, Type III) using the program package of STATISTICA 4.5. The average values of VE were similar in the three seasons (summer: from 4.42 to 6.28 cm3, autumn: from 4.08 to 6.86 cm3, winter: from 5.43 to 5.71 cm3). The average values of the MC were similar in each of the three seasons (summer: from 3.66-4.00 M; autumn: from 3.66-3.77 M; winter: from 3.86-4.07 M). The summary of all effects for season (P<0.001), repeated sperm collections in the same season (P<0.05) and interaction of two traits (P<0.01) were established on the measured characteristics. The special effects (P<0.05) of a given season were calculated, excepting the VE and MC, on all of the measured characteristics. The special effect (P<0.01) of the repeated sperm collections in the same season was verified in only one case (SMS). It is not surprised at the interaction was established on the VE (P<0.001), PMS (P<0.05), and SMS (P<10.0). The results of present study suggest that seasonal effect on sperm quality of breeding bulls cannot be eliminated even at standard feeding and keeping conditions. Considering our results, we can recommend that the average values of three successive weeks in every season be used, to take advantage of seasonal effect on the quantitative and qualitative parameters of sperm production.

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Seasonal variations in somereproductive parameters of Dorper Rams in Hungary
17-20

The purpose of the present study was to test the hypothesis that season has an affect on semen quality and scrotal circumference of Dorper rams. The experiment was carried out with six Dorper rams aged between 15 and 18 month. Semen samples were collected with artificial vagina and volume, concentration (x 109/ml), total sperm number/ejaculate (x 109), mass motility (0–5), progressive motility (%), scrotal circumference (cm) was observed. Significant differences (P<0.05) were observed in concentration, total sperm number/ejaculate, scrotal circumference in different seasons. Volume was the highest in autumn (1.4±0.5 ml) and the lowest in the spring (1.3±0.4 ml). Concentration of semen was lower in spring (2.6±1.5 x 109) and summer (3.3±1.5 x 109) as compared to fall (4.1±1.1 x 109) (P<0.05). Regarding total sperm number/ejaculate (x 109), scrotal circumference (cm) all the seasons differed significantly (P<0.05), although the season had no effect on mass motility and progressive individual motility (P<0.05). In conclusion the present study showed that semen quality parameters and scrotal circumference of Dorper rams were better in autumn than in the other sea- sons.

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