Charakterystyka nasienia nutrii (Myocastor coypus Mol.) oraz możliwości farmakologicznego wpływu na jego konsystencję i właściwości biochemiczne
AbstractThere has been very little work regarding nutria males and females, especially in the aspect of their biology and physiology of reproduction. This was the reason to undertake complex studies whose aims were: — to determine the biochemical composition of nutria semen with special attention paid to the secretions of the accessory sexual glands, — to attempt to affect these secretion in a pharmacological way, — to define the differences in the morphology and biochemical composition of semen collected after pharmacological interference in these secretions. Investigations into the biochemical composition of semen and the secretions of sexual glands were conducted on the basis of 72 Grenland and Standard nutria males aged 1-3 years. Attempts at influencing the secretions of the accessory sexual glands by means of pharmacology were carried out on 25 Grenland nutria males 1-3 years old. Semen was collected from the males by electroejaculation (EE) method. Shortly before collection, the males were treated with the following pharmaceutical agents: Combelen (Propionylapromazinum, from Biowet Pulawy), Domitor (Medetomidinum, from Farmos Group Turku), Xylazinum (Xylazine 2 %, Rometan, from Leciva Praha), Ketalar (Ketamine hydrochloricum, from Parke Davis) and Halotane (Fluoroetan, from Spofa Praha). Immediately after semen collection, macro- and microevaluation was performed. Protein, fructose, total lipids, glycerophosphocholine, triacylogliceroles and citric acid levels were determined in the semen plasma and secretion of the accessory glands. The activity of AspAT, cholinoesterase and alkaline and acidic phosphatases was also evaluated. Differences in the structure of coagulated and fluid semen were tested by electron transmission microscopy and scanning microscopy. The highest level of protein was detected in the secretions of the follicular glands (37.28 g/1), the lowest one in the secretions of Cowper's glands (2.337 g/1). Among the protein fractions in semen plasma were: the albumin-like fraction (mean 32 %) and a-2 and f3-1 globulins (22.08 and 20.98 %, respectively). As in other animals, in nutria the basic sugar in semen is fructose, not glucose. The level of total lipids was high in the secretions of all the sexual glands, while in semen it was 4-5 times lower. The same relationships were observed in the cholesterol and triacylogliceroles content. No fatty acids with a chain longer than C18 were found in semen. Significant and highly significant differences were observed in the activity of all the tested enzymes. The greatest differences were noted in alkaline phosphatase and aspartic aminotransferase. All attempts to obtain ejaculates using Rometan (Xylazine), Domitor + Atropine + Ketamine and Atropine + Xylazine + Ketamine proved to be successful. The lowest efficiency was observed after Atropine + Combelen administration and halotane anaesthesia (66.67 %). With the first method used, quite frequently only the first fraction of semen was collected. In 25 cases (22.12 %) the collected semen was gelatinised. A 100 % gelatination was observed when halotane anaesthesia was applied, and 98.75 % after Combelen + Halotane administration. The mean volume of the collected ejaculates was 1.23 cm3 (maximum 8.0 cm3, minimum 0.2 cm3). The highest volume of the collected semen, that is 0.51 cm3, was observed after Atropine + Xylazine + Ketamine administration. After comparing the quality and properties of semen obtained by different means used for premedication, it can be concluded that the only agent which allowed the collection of non-gelatinised semen was Domitor. All males to whom it was applied gave good-quality semen (83 % defined as thick, 17 % as medium-thick) which, however, had a low concentration of spermatozoa (640 thousand/mm3). By using other agents, different percentages of semen coagulation were observed. The best results were obtained after Ketamine (Kemint) administration. Of 91.6 % positive trials, 64 % maintained milky consistency and only 9 % partly coagulated; such semen had a thick and stringy consistency and whitish colour. The males produced quite a large volume (1.6 cm3) of good-quality semen (82 % described as thick or very thick). These values were comparable to those obtained after Domitor administration, but the concentration of spermatozoa collected by this method was much higher (1985 thousand/mm3). Under the electron microscope, besides spermatozoa, it was possible to observe the presence of a substance having a loose or dense structure. Under the scanning microscope this effect of semen "fluidisation" was better noticeable. In the liquid semen a few formations with a grainy surface were observed, while in the coagulant almost the whole area in the microscope field of vision was filled with fibrous structures in which spermatozoa were present. Summarising the results, it can be concluded that electroejaculation carried out after previous pharmacological preparation (Combelen, Domitor, Ketamine) can be recommended as a useful method for semen collection from nutria males. Microscopic and macroscopic evaluation of semen, however, should be supplemented by the results of biochemical investigations including tests for protein and fructose levels as well as AspAT and alkaline phosphatase activity.
|Other language title versions||Characteristics of nutria (Myocastor coypus Mol.) semen and possibilities of pharmacological interference in its consistency and composition|
|Publisher||Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie, MNiSW |
|Publishing place (Publisher address)||Kraków|
|Book series /Journal (in case of Journal special issue)||Zeszyty Naukowe Akademii Rolniczej im. H. Kołłątaja w Krakowie. Rozprawy, ISSN 1233-4189, (0 pkt)|
|Publication size in sheets||3.8|
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