Wpływ pory roku i wieku zwierząt na parametry biologiczne nasienia szynszyli hodowlanych (Chinchilla lanigera)
AbstractIn Poland, chinchillas' raising and breeding have already over 60-year tradition. We are the world-class breeder of this species and one of the greatest global producers of their skins. The chinchilla females are seasonally polyestrous and low-fertile animals. Fertility of females of every species is influenced by males through the quality of produced sperm. Choosing infertile breeders or the ones that produce sperm with low biological parameters for the herd exposes breeders to financial loss. Breeding results in Polish farms clearly indicate that chinchilla females retain seasonality. The periods with increased and decreased breeding activity can still be observed. It can, therefore, be anticipated that males can he characterised by seasonal changeability of produced sperm, as well. Numerous parameters connected with feeding, health status, the season of the year, males' age or the obtaining technique influence the quality of sperm. Chinchillas are long-living animals and are often used as breeders over long periods. It would be interesting to receive an answer to the question to what extent the optimal conditions in farm breeding have influenced the sperm parameters. Providing such breeding conditions gives possibility for obtaining even three litters a year. However, clear diversity of frequency as well as the number of litters in particular months are observed. It is obviously reflected in intensity of mating but, for that reason, young animals reach their sexual and breeding maturity in various seasons of the year. Therefore, the main aim of the surveys was to determine the impact of the seasons of the year as well as the periods and length of breeding use of males on the biological parameters of sperm and the activity of selected spermatic enzymes and sperm plasma. The influence of time of reaching breeding maturity of young animals on the sperm quantity and biological quality was also attempted. The aim of our surveys was to determine the levels of selected biochemical and mineral compounds of both the sperm and secretions of sex glands according to the season of the year and the breeding season in relation to the males’ age. The method of collecting the sperm should be effective, possibly quick and simple and, most of all, safe for the animal. The only way of gaining the sperm from male chinchillas is stimulating by an electroejaculator which was used after obtaining the approval of the Local Ethical Commission. All procedures were performed by or in the presence of a veterinary surgeon. The animals kept in the battery system in cages recommended for that species according to EU standards were fed with granulated all-mash mix and hay three times a week. To calculate a proper dose of a pharmacological substance, the animals were weighted. Ketamine with Xylazine in one intramuscular injection were used for the infusion sedation and analgesia. The tests determining the impact of the season of the year and the age of males on the sperm parameters were performed collecting ejaculates regularly once a month all year round from 60 males from three groups: Group I – the males in the first year of breeding use, Group II – the males from the 2nd to the end of the 5th year of use, Group III – the males from the beginning of the 6th year of use. The impact of reaching sexual maturity of young animals on the sperm parameters in relation to the season of the year was performed on the basis of the sperm collected from 31 sexually mature males selected in such a way that they would achieve the age of 8–9 months in individual seasons of the year. The sperm was collected from 7–8 males twice in every season of the year, at monthly intervals. The levels of biochemical compounds in the sperm plasma were assayed on 48 ejaculates, 12 in every season of the year taking the periods and three age groups of animals into account. The level of biochemical compounds in secretions of sex glands was tested in 20 isolated segments of the reproduction system, from 10 animals in every period and age. The ejaculates were evaluated by means of the method of Bielański  in my own modification adapted to the species. The ejaculate capacity as well as the sperm colour, consistency and scent were determined in the microscopic evaluation. The share of moving sperm cells, individual sperms’ movement, concentration and total amount of sperms in the ejaculate and also their morphology were determined microscopically. The activity of acrosin was determined by means of the method of Kennedy and the others , and the activity of aspartate aminotransferase,lactate dehydrogenase and alkaline phosphatase by the kinetic methods using ready biochemical sets. The activity of enzymes was expressed both in U · l–1 and in conversion to U · 10–6 of sperms. The levels of total protein, albumin, glucose, triacylglycerols and cholesterol as well as: calcium, magnesium, potassium, sodium and ferrum in the sperm plasma and secretions of the sex glands were determined by means of the biochemical analyser COBAS INTEGRA 400 plus. The level of fructose was determined by the method of Mann and the one of citric acid by the method of Speck modified by Mann [Strzeżek and Wołos 2001]. The profile of fatty acids according to the modified method of Folch and the others  was determined in the sperm plasma, exclusively. On the basis of the performed surveys, it can be stated that using Ketamine and Xylazine for neuroleptic analgesia of chinchilla males allowed to obtain high efficiency of the used method of electroejaculation, whereas the optimal periods for its performance were springs and winters, particularly in young animals. UnsTable in individual seasons of the year, sperm parameters, their clearly lower values in macro- and microscopic estimation in autumns, higher activities of AspAT and LDH in the period of summer/autumn period and higher activity of acrosin in winter and summer allow to state that seasonal changeability is still preserved in physiology of male breeding. However, lower capacities and concentrations of sperm, decreased activities of acrosin and ALP as well as increased activities of AspAT and LDH in sperm plasma suggest that breeding use of males longer than six years is not recommended. Full reproductive ability in the age of 8–10 month was reached by the males in winter and spring. Chinchillas born at the end of the year, which is from September to December, did not reach full reproductive ability in that age.
|Other language title versions||The impact of season and animal age on biological parameters of sperm of the breeding chinchilla (Chinchilla lanigera)|
|Publisher||Wydawnictwo Uniwersytetu Rolniczego im Hugona Kołłątaja w Krakowie, MNiSW  [Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie]|
|Publishing place (Publisher address)||Kraków|
|Book series /Journal (in case of Journal special issue)||Zeszyty Naukowe Uniwersytetu Rolniczego im. Hugona Kołłątaja w Krakowie. Rozprawy, ISSN 1899-3486, (0 pkt)|
|Publication size in sheets||8.5|
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