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Aplikované aspekty kryokonzervace rybích spermií
Fish sperm cryopreservation becomes highly attractive due to increasing number of potential applications and it has been considerably developed over the past decades. Cryopreservation of fish sperm is expected to improve the broodstock management in hatcheries, simplify hybridization and selective breeding, and serve as a useful tool for biodiversity and conservation of endangered species programs. Nevertheless, its status nowadays is highly contentious due to absence of specific techniques and standardization in the developed protocols. Moreover, the heterogeneity of cryoresistance in sperm of some fish individuals and, strong impairment of the sperm quality and survival after cryopreservation, to date, present some challenges inhibiting wide applicability of this approach. Therefore, a better understanding of the mechanisms of spermatozoa cryo-injuries and the development of new and more effective methods for cryopreservation of fish sperm are of primary importance. In the current work, the causes of individual variability in sperm cryoresistance, influence of cryopreservation process on sperm quality parameters regarding application of uncontrolled cooling devices were investigated. One of the study outputs is the founding the possible causes of sperm cryoresistance heterogeneity in common carp (Cyprinus carpio) males. As a result, a negative correlation between changes in the contents of major lipid classes and sperm motility after cryopreservation was found. In particular, the increased level of phospholipid, cholesterol and free fatty acid in samples with low post-thaw motility percentage were observed and related to decrease in sperm cryoresistance in common carp sperm. In the investigation of the consequence of the application of uncontrolled cooling devices on post-thaw sperm parameters of sterlet sperm, it has been shown that sterlet sperm could be cryopreserved by both Styrofoam box and dry shipper devices studied. However, due to inability to precisely control cooling process in these devices, the cooling conditions can be changed by varying straw number during freezing in Styrofoam box or by straw position during freezing in dry shipper. As a consequence, these changes shift the optimal freezing rates needed for successful sturgeon sperm cryopreservation resulting in decrease in post-thaw sperm motility and fertilization ability. These results suggest the way of standardization of fish sperm cryopreservation protocols by selecting appropriate straw number or straws position when uncontrolled cooling devices are used. Finally, to explore the cryopreservation effects on fish spermatozoa, the Percoll density gradient centrifugation technique was elaborated and applied for the first time to sterlet (Acipenser ruthenus) sperm. That technique allows to select and analyse only the sperm population that survived cryopreservation procedure and saved high motility parameters. It was found that this spermatozoa subpopulation possesses minimal changes in protein profile in comparison to native sperm. Moreover, the differences in many proteins which were found in sperm suspension after cryopreservation without separation is related to the presence of non-viable and sperm wreckage subpopulations in the frozen-thawed sperm suspension. Collectively, all of these detected changes in sperm motility parameters, viability, and protein profiles of viable spermatozoa after freeze-thaw process suggest some explanations for the mechanism responsible for cryodamage of sperm and provides the background for further development of an efficient cryopreservation protocols. However, it should be also further studied if the Percoll separation technique could serve as a useful tool for both better understanding of non-lethal sperm cryodamages and improvement of assisted reproduction practice in sturgeon species.
Vyhodnocení produkčních vlastností romanovských ovcí v ekologickém chovu
Bachelor thesis focuses on fertilization, fertility, intensity of fertilization, breeding, number of infertile sheep, total number of sheep in reproduction, evaluation of descendants growth capacity and number of sheep with individuals, twins, triplets and quadruplets. The data obtained from the control of use and evidence from past years was used to evaluate these characteristics. The work highlights the advantages of farming and the shortcomings that occur in the breeding and at the same time it should contribute to the improvement of the situation on the farm.
Analýza reprodukčních vlastností plemene valaška
The aim of this diploma thesis is to evaluate the level of reproductive performance of Wallachian sheep. There were used data from the original kennel evidence and from the performance cracking. It is focused on fertilization, reproduction intensity, fertility and rearing lambs. Fertilization of Wallachian sheep was in between 89,5 99,4 percent. Reproduction was in between 141,4 158,1 percent. Level of rearing was in between 108,1 139,6 percent. There were born 972 lambs in years 2012 2016. The most lambs were born in the year 2016, it was 265 lambs. It is because there were the most ewes in the herd in the reporting period. There were born one lambs, twins and triplets. The most frequent were twins at a ratio of 49,9 percent. The less frequent were triplets at a ratio of 4,7 percent. Number of lambs does not depend on the age of ewes. The number of lambs in a the litter did not differ by lines.
Comparison of the reproduction of the goats on the ecological and the conventional farm
The aim of my diploma thesis is comparison and evaluation of reproduction of goats on an eco-farm and on a conventional farm. Measures of reproduction of observed herds were assessed in the years of 2009 and 2010 on an eco-farm Hana Langová and on a conventional farm Bára Schneedorferová. On an eco-farm, a herd of 20 does was observed. Crossbreeds of White shorthaired goat, Brown shorthair goat, Boer goat and Anglo-Nubian goat; all bred with a White shorthaired buck and a Boer buck. On a conventional farm, a herd of 24 White shorthaired does and two crossbred does of White and Brown shorthaired goat was observed in 2009. In 2010, only 18 does were observed. In both years the does were bred with two Brown shorthair bucks. The measured results were compared with milk efficiency results between the two years and also between the farms. In both years, higher fertility was discovered on an eco-farm. On a conventional farm, very low fertility was observed in 2009 (116 %). On the other hand, fertilization was higher than on an eco-farm in both years. Very big difference was also observed in the ratio of male kids, which was in both years higher on a conventional farm, where all the bred animals (apart from one) are hornless. Reproduction is to a high extent influenced by external environmental factors and to a very small extent by genetics. A whole range of possible effects was omitted from the observations, however, the main ones were noted. Of all the observed measures of reproduction, the only one which could be substantially influenced by the breeding method is fertility.
The comparison of two breed of sheeps reared in the same area
The comparison of two breed of sheeps reared in the same area. The aim of the master thesis was the evaluation of the level of the reproductive and the productive traits by the two breeds of sheeps in the area of Novohradské Hory Mts. The examination was conducted from 2006 to 2009. The farm recording and the author´s personal observation were both used for the evaluation. The following traits were recorded: insemination, fertility, intensity, lamb rearing, infertility, mortality. The production traits recorded were the weight of the wool and weight gain in 100 days after the birth. The following results (arithmetic means) were obtained: the rate of insemination by the Valaška breed was 94.3 %, fertility 168.4 %, intensity 158.5 % and the lamb rearing 150.2 %. The rate of infertility was 5.9 % and rate of mortality 5.1 %. The average wool weight was 2.21 kg and the weight gain 175.8 g day-1. By the Merinolandschaf breed, the rate of insemination was 87 %, fertility 134.4 %, intensity 116.1 % and the lamb rearing 101.5 %. The rate of infertility was 13.2 % and rate of mortality 8.8 %. The average wool weight was 4.2 kg and the weight gain 236.9 g day-1. The herd A revealed better results as regards the reproduction traits while the herd B revealed better results concerning the production traits. The significant differences between the examined herd of Valaška sheeps and the Czech population were found in the fertility, intensity and the lamb rearing (T test). By the Merinolandschaf herd, the significant differences from the Czech population were found by the weight gains (T test). The significant differences between the two breeds were found in the fertility, intensity and lamb rearing (T test).
The evalution of reproduction parametres in chosen herd of sheep
BENEŠOVÁ, Kristýna
It has been observed the breed herd of Texel sheep in the foothills area of Orlické mountains in the year 2005-2008. The base of herd was consisted of 374 ewes, 575 lambs and 6 rams in total. These parametres of reproduction {--} conception, fertility, rearing, empty ewes, abortions, lambing, stillborn, death after born, were monitored at ewes. For the parametres of reproduction at ewes were found significant effects of ewe´s age and ram´s line.

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