The Study Of In Vivo-embryos Collection And Transfer

In this study, the main factors to affect the Holstein-cow embryos collection wereexperimented, and the methods to improve embryos-transfer conception rate of Holsteincows were studied, with the aim at establishing a perfecter technical operating system invivo embryo collection-embryo transfer of Holstein cows. The main contents of thisstudy are the effect of primary factors on cow embryos collection and the main factorsaffect the Holstein cow embryo transplant.In the study of the effect on cows embryo collection technique, we research ondifferent artificial insemination units (1unit of straw frozen semen,2units of strawfrozen semen), different times of artificial insemination (1time,2times,3times) anddifferent lactations affect on embryos collection of donors. The results show asfollowing: under condition of artificial insemination3times to each donor, artificialinsemination in different units (1unit of straw frozen semen,2units of straw frozensemen) have no significantly difference(P>0.05) on numbers of embryos per donor orthe numbers of grade1and grade2embryos. Different of artificial insemination timesaffect the numbers of embryos, but no impact on the embryos quality. As the numbers ofembryos per donor, the1time of AI group（6.07士2.46，58.25%） is the lowest thanthe2times of AI group（10.34士2.68，94.52%）and the3times of AI group（10.43士2.43，94.56%）.There are no significant difference numbers of embryos per donorbetween the2times of AI group（10.34士2.68，94.52%）and the3times of AI group（10.43士2.43，94.56%).At last, the different lactations affect the numbers of embryos,embryos collection rate and embryos quality. As the numbers of embryos per donor forexample, there are no significant difference between the heifers group（10.34士2.89，95.74%）and the1stPlactation group（9.76士2.79，93.40%）. but the2nd lactation groupis significantly lower(P<.005)than the heifers group（10.34士2.89，95.74%） and the1stPPlactation group（9.76士2.79，93.40%）.The3rd lactation group（6.56士2.55，67.77%）is the significantly lowest(P<0.01)than the other three groups. This is the sameas the numbers of the grade1and the grade2embryos and the rate of the grade1andthe grade2embryos.In the research of the effect on cow embryos transfer technique, comparing thedifferent lactation receptors and the synchronization of estrus effect on the conception ratio.The results indicate that, the different lactation has the influence on the conceptionrate. For pregnancy numbers and pregnancy rate as an example, the heifers group(8heads,53.33%)is higher than the1stPlactation cows(7heads,46.67%),but there is nosignificant difference(p>0.05) between each other. The2ndPPlactation cows (5heads,33.33%) is significantly different(p<0.05) from the heifers group(8heads,53.33%)andthe1stPlactation cows (7heads,46.67%).The3rd lactation cows group(3heads,20.00%)is the lowest in all of the groups(p<0.01).Besides, the other research indicates asfollowing, there is no difference between the synchronization group and nosynchronization group,the receptors have the same conception rate after embryostransplant. It is also the same as the IVF fresh embryo and the in VIVO embryo. In thetreatment one group, the pregnancy number and the conception rate is no differencefrom the IVF embryo group(10heads,50%) to the Vivo embryo group (12heads,60%).In the processes two groups, the IVF embryo group pregnancy number andthe conception rate (10heads,50%) are not remarkable to the Vivo embryo group(11heads,55%).There are not more remarkable between Processes one group(22heads,55%) and process two groups (21heads,52.5%)on pregnancy receptors number and theaverage conception rate.