Study On Goat In Vitro Fertilization And It's Beneficial Factors

The aim of this study was to develop an improved IVF system for goat oocytes matured in vitro and prepare for the study of transgenic animal.Experiments were carried out to analyze different factors which reported influence the results of IVF and optimized the technology of IVF in goat.Two methods,surface cutting and aspiration,were used for recovering the usable cumulus-oocyte complex(COCs) from surface-visible follicles of slaughtered goat ovaries.The total number of COCs recovered per ovary by surface cutting: is significantly higher than that collected by aspiration (3.70 per ovary vs 2.31 per ovary). COCs were obtained from slaughtered goat ovaries during the breeding and nonbreeding seasons by surface-follicles cutting.The results showed that the recovery of COCs from slaughtered goat ovary by surface-follicles cutting is efficient compared with the aspiration and more COCs could be recovered by surface-follicles cutting during the nonbreeding seasons than the breeding seasons(4.13 per ovary vs 3.42 per ovary).The percentage of maturation were counted in breeding seasons and in nonbreeding seasons.The results showed that COCs recovered from nonbreeding seasons were better than from breeding seasons (61.3%vs 72.5%).The maturation rate of COCs collected from ovaries transported for 6-8h at 20-24C,25-29C and 30--35C was 68.5%,67.9% and 54.2%, respectively.The results suggested that the maturation rate of slaughtered goat ovaries which placed above 30 C was signifficantly lower than that placed under 30C.There were no differences between the maturation rates ofgoat oocytes cultured in medium supplemented with FSH/LH and with HMG(67.5% vs 70.2%).The maturation, rates were not different between the medium supplemented with PCS and EGS.The maturation rate of the goat oocytes with diameter 4> < 150 u m, 150 u m< 4> < 160 u m, 4> > 160 u m was 0.74%,69.5%and71.6% respectively.The results showed that goat oocytes have acquired full meiotic competence at a diameter of 150 U m.When cultured for 16h,20h,24h and 27h,the maturation rate was 22.6%,31.2%,57.2% and 72.4%, the results showed that experienced 27h culturing the most COCs could aquire maturation .1.Fresh ejaculates of proven fertility were processed according to the following treatments:1) centrifugation,2) by swim up,3) by dilution.In all treatments spermatozoa were incubated for 45mins or Ih or 2h or 3h with 50 u g/ml of heparin.The results showed that swim-up is the best method to treat goat spermatozoa.2.Spermatozoa was incubated in medium TALP or mDM or mH-M199 to capacitate.The results showed that the highest capacitation rate could be gained when mDM used as capacitation medium.3.After incubated in medium TALP for 45mins or Ih or 2h or 3h,the capacitation rate was 12.4%,15.8%,48.7% and 51.0% respectively.The results showed that the capacitation rate incubated for 2-3h was significantly higher than which incubated for shorter than 2h.4.Spermatozoa was incubated in calcium-ionophore A23187(IA23187),when the concentration of IA23187 was 0.2, 0.5,1 u M the capacitation rate was 47.5%,45%,53.8% respectively. The viability of sperm incubated in 0.2 n M IA23187 medium was significantly higher than which in 0.5 u M and 1 u M IA23187 medium.When spermatozoa was incubated in IA23187 medium for 2 mins,5 mins and 10 mins,the capacitation rate was 36%,48%,53%. The viability of spermatozoa after incubated for lh,5h,15h was 76%,46%,23%;75%,42%,24%;53%,32%, 6%, respectively. The capacitation rate was 48.2%,46.8%,51.2% in IA23187medium which supplemented with FCS,BSA,FCS+BSA respectively. The viability of lh,5h,15h was 0.70,0.50,0.20; 0.50,0.35,0.10; 0.60,0.40,0.10.A11 the results suggested that if IA23187 is apllied as capacitation medium,the concentration shoud be selected 0.2 u M and the time spermatozoa incubated in it should be 5 mins and PCS was beneficial for sperm's viability.Oocytes and sperm cells were incubated for 17h in TALP,mDM,m H-M199 and the fertilization rate was 52.3%,50.8%,41.7%.The fertilization rate is significantly lower in m H-M1...