Tesis doctoral de Ester Taberner Brugué
The aim of this work is the knowledge of catalonian donkey reproductive features of its females and males in order to apply reproductive technologies to maximize the production of live foals and help conserve the breed. in the first work we studied the reproductive behaviour, oestrous cycle characteristics and indicators that predict the moment of ovulation of the catalonian donkey. The main signs of oestrus detected were mouth clapping, urinating and contraction and relaxation of the labia of the vulva with eversion of the clitoris. The length of the oestrus cycle was 24.9 ± 0.3 days, with oestrus itself lasting 5.6 ± 0.2 days. The mean diameter of the preovulatory follicle at day -1 was 44.9 ± 0.5 mm and we observed high incidence of multiple ovulations (44.3%). The combination of follicle size, follicle texture and oestrous behaviour were the best predictors of ovulation. in the second study we evaluated the effects of dilution and centrifugation (two methods of reducing the influence of the seminal plasma) on the survival of spermatozoa and the structure of motile sperm cell subpopulations in refrigerated catalonian donkey semen at 24, 48 and 72h. At 48h, more surviving spermatozoa were seen in the more diluted (1:10) and in the centrifuged semen samples. The four donkey motile sperm subpopulations were maintained by refrigeration and centrifugation, moreover only centrifuged samples and only at 24h (5ºc) showed exactly the same motile sperm subpopulation proportions as recorded for fresh sperm. in the third work we assessed the effect of three storage temperatures (5, 15, 20ºc) on the survival and motility of catalonian donkey sperm during transport (2h) to the laboratory for centrifugation. All treatments maintained the four motile sperm subpopulation, but 2h of storage at 20ºc followed by centrifugation was the treatment that maintained subpopulation structure more similar than fresh samples. in the fourth study we evaluated the influence of freeze/thawing on motile sperm subpopulations and sperm viability in ejaculates from two phylogenetically different mammalian species, boar and donkey. Boar and donkey sperm respond very differently in their mean motion characteristics to freezing/thawing, this process did not change the existence of a 4-subpopulations structure in the ejaculates. Motility changes induced by freezing/thawing protocol are especially linked to changes in the specific percentage of each of the motile sperm subpopulations. in the last work we studied the interaction between fresh/frozen-thawed donkey spermatozoa and zona pellucida (zp)-free bovine oocytes in an attempt to develop a model for assessing cryopreserved catalonian donkey sperm function. The donkey spermatozoa were able to fuse with the oolema and even to decondense and form the male pronucleus (85-94%). Fresh or frozen-thawed high viability (>60%) spermatozoa had higher penetration percentage than fresh or frozen/thawed low viability (<40%) spermatozoa. A significant positive correlation (p<0.01) was detected between percentage fertilization and viability (r=0.84), and between percentage fertilization and certain casa parameters (vap, r=0.56; vcl, r=0.61; and mean alh, r=0.68). in conclusion, the exact moment prediction of ovulation in catalonian jennies and adequate donkey semen manipulation and cryopreservation should have a positive impact upon the reproductive technologies application. Such knowledge should help maximize the production of live foals and help conserve the breed.
Datos académicos de la tesis doctoral «Tecnologies reproductives aplicades a la conservació del burro catalÁ «
- Título de la tesis: Tecnologies reproductives aplicades a la conservació del burro catalÁ
- Autor: Ester Taberner Brugué
- Universidad: Autónoma de barcelona
- Fecha de lectura de la tesis: 21/06/2010
Dirección y tribunal
- Director de la tesis
- Jordi Miró Roig
- Tribunal
- Presidente del tribunal: Juan Carlos Dominguez fernandez de tejerina
- concepcion Gómez-cuétara aguilar (vocal)
- (vocal)
- (vocal)