Abstract. In this study, the quantitative and qualitative traits of semen were studied in seven rams of different breeds (Prolific Merino, Cokanski Tsigai, Barbados Blackbelly, Bábolna Tetra, Awassi, Ile de France and Suffolk), bred in Hungary. The semen parameters (density, volume, pH, mass motility, % motility, thawing and heat resistance), freezability of semen and the factors influencing these parameters were evaluated with respect to breed and season. The fresh and post-thawing quality of semen varied greatly with the breed and the season. The postthawing motility of semen cells was outstandingly high for Awassi rams in three seasons. During the test period, the smallest scrotal circumference was measured for Barbados Blackbelly, except for the summer when it increased by 12.5 cm. The reintroduction of artificial insemination could lead to a significant advancement of the sheep sector in Hungary. To promote this, we have provided useful and new information for breeders and organisations.
The current knowledge and documentation on the origins and relationship between Gyimesi Racka reared in Hungary and the Romanian Turcana is rather controversial. Lack of information and scientific reliable proofs for the divergent theories found in the two countries motivated us to implement a trial using molecular methods to assess the genetic distance and diversity in the two breeds. Hair follicles were collected from Gyimesi Racka (2 phenotypes) and from Turcana (6 ecotypes). The 599 bp segment of the D-loop region of the mitochondrial DNA was sequenced. Altogether, 42 haplotypes were identified, while 23 were found in both populations. Populations were highly diverse according to the haplotype and nucleotide diversity indices. AMOVA analysis showed that most of the variation was observed within populations (98%), indicating a weak genetic structure between the two breeds. Animals were grouped into seven groups based on their phenotype; however genetic distances among them were also low. Tajima's D, Fu's Fs, goodness-of-fit statistics, mismatch distribution and network analysis suggested recent demographic expansion. Current comprehensive mtDNA study indicates that there is very low level of genetic differentiation between the Gyimesi Racka and Turcana populations therefore they are de facto one trans-boundary breed.
The objective of the current pilot study was to evaluate the reproductive performance and health indicators in Dorper, White Dorper, and Tsigai breed ewes managed semi-intensively under European temperate conditions. A total of 544 ewe-year units were observed, with ewes (ranging from 1.5 to 8 years of age) managed under identical rearing conditions for a period of two consecutive production cycles (2012 through 2013 and 2013 through 2014). In general, significant (p≤0.001) genotype-related disparities were found in occurrence rates for all health parameters taken into study. Clinical mastitis incidence was significantly lower (p≤0.05) in Dorper (9.4%) and White Dorper (10.8%) breeds compared to that of Tsigai ewes (17.4%). Significant differences (p≤0.05) for lameness were found between Dorper and Tsigai breeds, with occurrence rates of 8.0% and 2.9%, respectively. Incidence for pneumonia and abortion was not influenced (p>0.05) by the ewes’ genotype. Litter size was significantly lower (p≤0.05) in White Dorper breed than for Dorper and Tsigai ewes, of 1.21, 1.40, and 1.45, respectively. Conception rates and lambs survival were not affected (p>0.05) by genotype. Results suggest that South African Dorper and White Dorper sheep breeds have adapted well to the specific rearing conditions.
The purpose of the present study was to test the hypothesis that season has an affect on semen quality and scrotal circumference of Dorper rams. The experiment was carried out with six Dorper rams aged between 15 and 18 month. Semen samples were collected with artificial vagina and volume, concentration (x 109/ml), total sperm number/ejaculate (x 109), mass motility (0–5), progressive motility (%), scrotal circumference (cm) was observed. Significant differences (P<0.05) were observed in concentration, total sperm number/ejaculate, scrotal circumference in different seasons. Volume was the highest in autumn (1.4±0.5 ml) and the lowest in the spring (1.3±0.4 ml). Concentration of semen was lower in spring (2.6±1.5 x 109) and summer (3.3±1.5 x 109) as compared to fall (4.1±1.1 x 109) (P<0.05). Regarding total sperm number/ejaculate (x 109), scrotal circumference (cm) all the seasons differed significantly (P<0.05), although the season had no effect on mass motility and progressive individual motility (P<0.05). In conclusion the present study showed that semen quality parameters and scrotal circumference of Dorper rams were better in autumn than in the other sea- sons.
Laboratory methods of semen evaluation are used to select males for artificial insemination. The current review describes several techniques that have been recently used for sperm analysis. Conventional microscopic methods in combination with the objective computerassisted sperm motility and morphology analyzers and flow cytometry, allows to obtain more precise information about the membrane and functional status of spermatozoa. By using several methods to detect motility, viability, acrosomal and capacitation status besides DNA integrity sperm biology and some of the mechanism involved in sperm cry injury can be better understood. The number of possible targets related to sperm quality is increasing, and possible that some of them could enable sperm analysis for predicting freezability and fertility to be improved.
BackgroundCryopreservation of zebrafish embryos is still an unsolved problem despite market demand and massive efforts to preserve genetic variation among numerous existing lines. Chilled storage of embryos might be a step towards developing successful cryopreservation, but no methods to date have worked.MethodsIn the present study, we applied a novel strategy to improve the chilling tolerance of zebrafish embryos by introducing a preconditioning hydrostatic pressure treatment to the embryos. In our experiments, 26-somites and Prim-5 stage zebrafish embryos were chilled at 0°C for 24 hours after preconditioning. Embryo survival rate, ability to reach maturation and fertilizing capacity were tested.ResultsOur results indicate that applied preconditioning technology made it possible for the chilled embryos to develop normally until maturity, and to produce healthy offspring as normal, thus passing on their genetic material successfully. Treated embryos had a significantly higher survival and better developmental rate, moreover the treated group had a higher ratio of normal morphology during continued development. While all controls from chilled embryos died by 30 day-post-fertilization, the treated group reached maturity (~90–120 days) and were able to reproduce, resulting in offspring in expected quantity and quality.ConclusionsBased on our results, we conclude that the preconditioning technology represents a significant improvement in zebrafish embryo chilling tolerance, thus enabling a long-time survival. Furthermore, as embryonic development is arrested during chilled storage this technology also provides a solution to synchronize or delay the development.
The aim of our study was to examine how different gelatin concentrations affect ram semens viability in liquid storage at 5 oC for five days. Our hypothesis was if we add gelatin to the semen extender, than the viability of ram semen will be better in the extenders containing gelatin, than the control. We used two different semen extenders:1.5% UHT milk and 1.5% UHT milk + 5% egg yolk. We added 0; 0.5; 1.0; 1.5; 2.0% Dr. Oetker gelatin to the semen extenders. We stored the semen for five days at 5 oC and in every 24 hour we made sampling.We stained the smears with Kovács-Foote staining and evaluated them with light-microscope. We categorized the cells in five groups like: live and intact cells, live cells with injured acrosome, dead cells, live head with dead tail and live tail with dead head. We used one-way analysis of variance (ANOVA) to assign how gelatin concentration affects the number of the categorized cells. On the fifth day, the viability was the best in the following semen extenders: 1.5% fat UHT milk + 1.0% gelatin and 1.5% fat UHT milk + 1.5% gelatin, but it was not significant (p>0.05).
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