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Semen quality undergoes seasonal changes induced by multiple environmental factors of which the lenght of day­light plays the most important role. The pineal gland and its secretions are mediators in the transmission of light information. Sexual activity in rams increases during the shortening of daylight length. Therefore an application of artificial light programme enables to obtain a few breeding seasons within a year. Many experiments have shown that maintenance of proper light rigour may extend the period of a high sexual activity typical for a breeding season. Currently performed studies try to explain what systems are responsible for photosensitivity in these animals and in what way theoretical studies may be used in practice of the species reproduction.
Evaluation of the ram semen quality on the basis of some quantitative and qualitative indicators does not provide full information about the male’s usefulness for reproduction. This explains why studies on the use of biochemical indicators for determinating the biological quality of semen have been performed for many years. Measuring the concentration of some compounds (fruc­tose, citric acid, seminal plasma proteins) in semen plasma enables the secretory activity of the accessory glands to be evaluated. Comtemporary biochemical studies are ma­inly focused on determining the changes in the activity of plasma and spermatozoon enzymatic systems. Determina­ting the activity of the acrosine system (acrosine and its inhibitors), aspartic aminotransferase (AspAT) and alkaline phosphatase is particularly important.Evaluation of the ram semen quality on the basis of some quantitative and qualitative indicators does not provide full information about the male’s usefulness for reproduction. This explains why studies on the use of biochemical indicators for determinating the biological quality of semen have been performed for many years. Measuring the concentration of some compounds (fruc­tose, citric acid, seminal plasma proteins) in semen plasma enables the secretory activity of the accessory glands to be evaluated. Comtemporary biochemical studies are ma­inly focused on determining the changes in the activity of plasma and spermatozoon enzymatic systems. Determina­ting the activity of the acrosine system (acrosine and its inhibitors), aspartic aminotransferase (AspAT) and alkaline phosphatase is particularly important.
Four rams of Polish long-wool sheep were intensively used in course of one year in an experimental scheme: 10 periods of semen collection, 10 ejaculation daily for 10 consecutive days in each period. It was found that the concentration and number of spermatozoa decreased significantly in the last (10th) ejaculates compared to the first ones. Apart from these qualitative changes connected with intensive use of the animals, it was also noted that the season of semen collection affected semen quality. The highest concentration and number of spermatozoa was observed in the ejaculates collected during the period November-March, the lowest ejaculate volumes were recorded in spring, whereas percentage of spermatozoa with damaged acrosomes was noticeably higher in July and August. Increased frequency of ejaculation was connected with possibly lower share of epidydimis secretion in the ejaculate. This resulted in considerable decrease of the activity of plasmatic proteinase inhibitors in the last (10th) ejaculates. Studies showed that changes in the inhibitor activity in ram seminal plasma in the annual cycle were caused by variations in the intensity of secretion of these substances, as well as bonding of the inhibitors by proteinase liberated from damaged acrosomes. Intensive sexual exploatation of rams may lead to some disturbances in the system protecting seminal proteins against unspecific proteolysis.
The microstructure of fresh and three days-stored Balady bread was studied using two different microscopic methods (LM and SEM). These both techniques revealed a great differences in the starch micro- structure as well as protein distribution between two layers of fresh Balady bread. The lower layer of Balady bread is characterized by the greater extent of starch geletinization as compared to the upper one. The upper layer of Balady bread is formed by continuos protein matrix with embedded lenticular-shaped starch granules. The microstructure of Balady bread after 3 days of baking differs from that of the fresh one mainly in the starch granules structure. The visible differences seem to be connected with different degree of starch gelatinization in each of the layers as well as free water (released from granules) redistribution between the layers. It was found that mainly these changes in stored bread allowed rapid rétrogradation of the main soluble starch component - amylose.
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