Állattenyésztési Tudományok Doktori Iskola

Állandó link (URI) ehhez a gyűjteményhez

https://hdl.handle.net/2437/2303

Mezőgazdaságtudományi Kar

Állattenyésztési Tudományok Doktori Iskola
(vezető: Dr. Komlósi István)

Agrártudományi doktori tanács

D52

Doktori programok:

  • Állatitermék-előállítás
    (programvezető: Dr. Jávor András)
  • Takarmányozás, halbiológia
    (programvezető: Dr. Babinszky László)
  • Szaporodásbiológia
    (programvezető: Dr. Rátky József)
  • Genomika
    (programvezető:Dr. Kusza Szilvia)
  • Állatnemesítés - Génmegőrzés, Állatökológia
    (programvezető: Dr. Komlósi István)

Böngészés

Állattenyésztési Tudományok Doktori Iskola Tárgyszó szerinti böngészés "Andromed®"

Megjelenítve 1 - 1 (Összesen 1)
  • Nincs kép
    TételSzabadon hozzáférhető
    Development of assisted reproductive technologies for ex-situ in vitro gene conservation in sheep
    Mujitaba, Malam Abulbashar; Pálfyné Vass, Nóra; Bodó, Szilárd; Állattenyésztési Tudományok Doktori Iskola; Mezőgazdaság-, Élelmiszertudományi és Környezetgazdálkodási Kar
    The current study involved three different experiments to assess the effects of epididymal spermatozoa (EPS) collection methods, ram breed, three (3) different commercial soy-lecithin-based semen extenders {Andromed® (AND), Bioxcell® (BIO), and OviXcell® (OVI)}, and two spermatozoa concentrations (400×106 vs 200×106 spermatozoa/ml) on the freezability of ram epididymal spermatozoa (REPS). Lastly, we evaluated the developmental kinetics of in vitro-produced sheep embryos fertilized with post-thaw REPS using ivf-Bioscience bovine media to enhance the conservation of local sheep breed genetic resources (GnR). Fourteen pairs of testes from German Mutton Merino (Merino:7) and Hungarian Black Racka (Racka:7) rams collected from a slaughterhouse for Experiment I. Post-mortem REPS were retrieved from the cauda epididymides by either Slicing or Incision method. Fresh samples were extended to 200×106/ml, filled into mini straws and equilibrated at 5 oC for 2 hours. Freezing was performed manually in a Styrofoam box. The fresh and post-thaw REPS’s Standard motility (SMP) and kinematic parameters (KP) were assessed using a CASA. The collection method did not significantly affect REPS’s fresh and post-thaw SMP and KP. The Merino breed had significantly (p<0.05) higher testicular weight (TW); in contrast, the Racka breed had significantly (p<0.05) better fresh LIN, STR, BCF and ALH and higher post-thaw LIN and BCF values. The Merino has heavier testicles and significantly (p<0.05) better cryo-tolerance in total motility, while the Racka fresh and post-thaw REPS have more linear movement and presented significantly (p<0.01) higher cryo-tolerance in most of the KP than the Merino Breed. In experiment II, the REPS were retrieved from nine adult rams’ testes of different breeds and diluted with each of the 3 extenders to both concentrations. Straws were frozen manually. SMP and KP were assessed by CASA, while spermatozoa viability, morphology and acrosomal integrity were evaluated using the Kovacs-Foote staining technique. The concentration did not significantly affect all the pre-freeze and post-thaw SMP and KP of REPS. The BIO and OVI had significantly higher pre-freeze and post-thaw BCF, post-thaw VAP and percentage of spermatozoa with intact head membranes than the AND. In contrast, the AND had a significantly lower percentage of REPS with tail defects than the BIO and OVI. The 400×106 spermatozoa/ml resulted in a significantly higher percentage of all intact head membranes than the 200×106 spermatozoa/ml. Experiment III comprised five (5) programs involving 216 cumulus-oocyte complexes (COCs). The COCs were matured for 23-24 hours, while IVF with post-thaw REPS in ivf-Bovine bioscience media. Viable sheep embryo with good developmental competence: overall cleavage rate of 43.0 %, a morula of 40.0 %, and a blastocysts rate of 21.0 % were obtained, comparable to those reported in the literature. In conclusion, breed significantly affects REPS cryo-tolerance, and either of the collection methods can be used to retrieve REPS without adverse effects. Freezing significantly increased tail defects and decreased the percentage of REPS with distal cytoplasmic droplets. Cryopreservation of REPS is recommended in 400×106 spermatozoa/ml concentration. All three extenders must be optimised to preserve viability, membrane integrity and better normal morphology of REPS. In vitro embryo production using post-mortem/abattoir-sourced gametes can be an alternative to MOET and ovum pick-up in cryo-banking of valuable local sheep breeds.