Although numerous studies reported the effects of heat stress in chickens, it was not investigated in the Transylvanian Naked Neck breed. In our research, Transylvanian Naked Neck chickens, 24 h after hatching, were heat-treated at 38.5 °C for 12 h. We compared the control and heat-treated adult chickens’ productivity parameters following 12 weeks of heat-stress at 30 °C. We found that the heat-treated layers had significantly higher egg production in heat stress, but in cockerels, the sperm quality did not differ significantly between the two groups. To detect the effect of heat-treatment on a molecular level, the expression of two heat-shock proteins and four heat-shock factors were analysed in the gonads of control and heat-treated chickens. We found that the expression level of HSP90 and HSF4 increased significantly in heat-treated female chicken gonads. Still, in adult females, the expression of HSF2 and HSF3 were substantially lower compared to the control. In adult heat-treated males, the HSP70, HSF1 and HSF3 expression levels showed a significant increase in both gonads compared to the control. We think that the presented significant differences in egg production might be related to the increased expression level of HSP90 and HSF4 in heat-treated female gonads.

Changes in plasma DHEA, testosterone (T) and 17-B-oestradiol (E2) levels were examined in domestic geese of both sexes in the fall and winter. The levels of steroid hormones were determined in blood plasma by means of radio-immunoassay (RIA). A so-called second (autumn) cycle was induced in geese via a dark-room preparation and natural keeping conditions. The plasma levels of DHEA showed a minor peak at onset of the autumn breeding and a major one prior to the more intense spring reproduction in both sexes. The seasonal curves of plasma DHEA appeared fairly similar in ganders and layers and without considerable differences between the absolute values. In ganders, plasma DHEA peaks preceded the elevations in T levels in the fall and spring alike. With layers, in turn, the autumn and spring peaks of plasma DHEA appeared after the peaks in E2 levels. With ganders, the concentration of plasma T seemed to predominate between the two androgens throughout the experimental period. With layers, in turn, the concentration of DHEA surpassed the level of plasma E2 at the time of the peak periods and other times during the study, as well. In domestic geese, DHEA is probably involved in the autumn physiological processes and the induction of reproduction during fall and early spring periods, alike.

As an alternative method for preserving female genetic material, the cryopreservation and orthotopic transplantation of day-old gonadal tissue have become well-developed techniques in a few poultry species. The aim of the present study was to apply these methods for the first time to domestic geese. Cryopreservation was accomplished using the previously developed vitrification technique. Native and frozen/thawed White Hungarian geese ovarian tissue was transplanted onto Grey Landes geese recipients. Both donors and recipients were less than 24 h old. The surgical protocol previously used in chickens needed to be modified regarding anaesthesia; ketamine, xylazine, and midazolam were administered partly intramuscularly and partly intravenously. After sexual maturation, the Grey Landes recipients were paired with White Hungarian ganders, and eggs were collected and hatched individually. The origin of the offspring was determined by phenotype- and microsatellite markers. Donor-derived offspring were obtained from native and frozen/thawed ovarian tissue transplantation, which had not been published earlier. The ratio of donor-derived progeny producing layers was 40% and 58% in native and frozen/thawed gonadal tissue transplantation, respectively. The highest rate of donor-originated progeny was 78.9%. Consequently, gonadal tissue transplantation appears to be a suitable method for preserving female genetic material in domestic geese; the technique is already implemented in Hungarian gene bank practice.

The objective of this study was to clarify whether the most-common species of Mycoplasma are capable of being detected in the reproductive organs and the cloaca, as well as in the semen of asymptomatic native Hungarian male geese. As it is necessary for the semen of that breed to be preserved pathogen-free in an in vitro gene-conservation program, the presence of and sources of infection, as well as prevention of the survival of pathogens following semen cryopreservation are key issues. 10 asymptomatic, two-year-old ganders were tested. For the detection of mycoplasmas, samples were taken from both fresh and frozen/thawed semen, cloaca, phallus lymph, testes and vas deferens, that is 5 samples from each of the 10 ganders. The semen was statically frozen using dimethyl-formamide as a cryoprotectant and stored in liquid nitrogen at -196 °C. Species-specific PCR systems targeting M. anserisalpingitidis, M. anseris and M. cloacale were used for screening and identification. Results of this study have shown, for the first time, that 1) among the three Mycoplasma species examined, all were detectable in the indigenous Hungarian ganders, with no clinical signs. 2) The pathogens could be detected in the cloaca, in both fresh and cryopreserved semen samples, but remained undetected within the inner reproductive organs. 3) As pathogens were able to survive the freezing/storing/thawing procedures, the possibility of vertical transmission of the pathogens during artificial inseminations does exist, which causes problems in the in vitro gene-conservation programs for this breed.

Cryopreservation of rabbit semen represents an important tool for the conservation of genetic resources; however, reduced post-thaw sperm motility may limit its practical application in artificial insemination (AI) programmes. The present stud...

It is well established that semen freezability varies considerably among rabbit breeds and lines, therefore, breed-specific cryopreservation protocols are required. In the study, three experiments were conducted. Semen quality was assessed based on sperm motility, the proportion of live/dead cells and morphological abnormalities. In Experiment 1, modified Lake's, BotuCrio and INRAFreeze extenders were compared using a simple static cryopreservation protocol. Post-thaw sperm motility was significantly higher with modified Lake's and BotuCrio than with INRAFreeze. However, no significant differences were found in the proportion of live, intact cells, therefore, modified Lake's extender was selected for further studies. In Experiment 2, the timing of cryoprotectant addition was evaluated. In half of the samples, 8% dimethyl sulfoxide (DMSO) was added at the beginning of the 45-minute equilibration period, while in the other half it was added only during the final 5 min. Both the percentage of live, intact cells and total motility were significantly higher when sperm were exposed to the cryoprotectant for only 5 min. In Experiment 3, modified Lake's extender supplemented with 1% glycerol and 4% dimethylformamide (DMF) was compared with BotuCrio using a rapid freezing protocol. Sperm motility and the proportion of live, intact cells were significantly higher with the modified Lake's containing glycerol and DMF than with the BotuCrio. In conclusion, the most effective method identified in this study for rabbit semen cryopreservation was the use of modified Lake's extender supplemented with 1% glycerol and 4% DMF.