Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 27

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
One of the methods of functional assessment of semen is the zona free ova test of an egg cell devoid of zona pellucida, as a result of treating it with trypsyne. This test facilitates checking the interactions between a spermatozoon and an egg cell and determining the fertilization potential of spermatozoa. The material used for the study was sperm collected by using the massage method from 18 polar foxes. Next, oocytes devoid of zona pellucida were introduced into the breeding medium and incubated together with the spermatozoa. Percolls gradient (Pharmacia, Uppsala Sweden) was used in order to separate the spermatozoa. The number of oocytes having both pronuclei (male and female) was determined, and these were used as the basic indicator of proper insemination. The study also took into account the number of oocytes which indicated so-called parthenogenic development (1 pronucleus) as well as those which underwent polyspermic insemination (3 or more pronuclei). The fertility (covering effectiveness) and profligacy of the investigated specimens was determined in order to assess the reproductive efficacy of male specimens on the basis of the number of covered female specimens, the number of whelped female specimens and the number of puppies. The investigated population was characterized by high breeding effectiveness which is supported by studies showing the high fertilization percentage of hamster oocytes in the zona free ova test (67.1%) and their breeding results (fertility 91.02%, profligacy 9.28). The results of the study indicate the utility of the zona free ova test in assessing fertilization capacity of spermatozoa and semen fertility in polar foxes.
The aim of this work was to evaluate the fertilizing capacity of bulls on the basis of the assessment of fresh and thawed semen, following the swim-up procedure and immunological assay with IgA and IgG antisperm antibodies. In addition, the suitability of immunological reaction with IgG and IgA antisperm antibodies for seminological assessment of bull semen was examined. Tests were conducted with semen originating from Holstein-Friesian bulls. Ejaculates were collected twice from 15 two-year-old males, yielding 30 samples of semen. After the calculation of sperm concentration and motility, the samples were diluted with Biociphos-Plus® and frozen in straws. After thawing, sperm concentration and motility were calculated again (an average of 101.4 million sperm/ml with a motility of around 21%), and the spermatozoa were subjected to swim-up. At the same time, frozen-thawed bull semen was tested for the presence of antisperm antibodies, using SpermMar Tests for IgG and IgA. According to the records of the insemination centre, 53 515 insemination treatments had been conducted with semen of selected bulls. In a population of 30 324 cows, the calculated insemination index amounted to 1.76. Half of the cows which were qualified for insemination had already been fertilized with the first treatment (ca 52.8%). After the swim-up, there was an average of 4.5 million hyperactivated spermatozoa with a motility of around 41%. Furthermore, spermatozoa associated with IgG antisperm antibodies were found in 20 ejaculates, i.e. in around 66.67% of all semen samples obtained. The spermatozoa reacted positively with IgA antibodies in as many as 23 samples, which constituted 76.67% of all ejaculates obtained. Correlations between the routinely analyzed semen parameters and the selected parameters (immunological, swim-up) which were demonstrated in this work, did not appear to be sufficiently convincing. Therefore, it seems necessary to repeat this study with a population of clinically healthy, fertile bulls, as well as with juvenile bulls newly introduced to the insemination centre or with bulls with reduced fertility.
In connection with scarce publications on the qualities of polar fox semen and the mutual relationship between particular features of the semen, the undertaken research aimed at specifying selected polar fox semen indicators and determining possible mutual correlations between them. The semen for analysis was collected 7 times from 18 foxes during the period of their sexual activity. In total, 126 ejaculates were obtained and they underwent detailed assessment. The total ejaculate bulk was determined as well as mass spermatozoa movement, the proportional share of hyperactive spermatozoa (preceded by sperm rotation in the percoll’s gradient), ejaculate pH, fructose concentration, the proportional share of spermatozoa not connected with antisperm antibodies and the proportional share of spermatozoa characterized by structural differences. Additionally, the interdependence between the semen quantity and quality and the breeding effectiveness of the analyzed foxes was examined and assessed. The results of the research indicate the high biological quality of the semen investigated during the whole breeding period, which led to high breeding results. The interdependence between the over all effectiveness of the analyzed specimens and the spermatozoa movement, and the proportional share of hyperactive - i.e. ready to fertilize - spermatozoa was observed. This indicates that separating spermatozoa in the percoll’s gradient as a method of spermatozoa preparation allows for in vitro selection of specimens of the best qualities and is useful in case of applying insemination.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.