Study Of Ovum Pick-up And In Vitro Fertilization In Dairy Cattle

The aim of this study was to establish an steady and efficient(ovum pick-up,OPU)and(in vitro fertilization, IVF)system in our lab.Experiments were carried out to analyze the different factors reported influence the results of OPU and IVF in dairy cattle.Study of OPU:1.The compare of oocyte taking from dairy cattle twice and once per week.The average number of oocytes (5.14,4.66;P>0.05)was not significantly different between the two groups;whereas,the high quality oocyte rates(80.5%,65.9%;P<0.05)twice per week were higher than once per week.2.The dairy cattle treated by hormones and untreated.The average number of oocytes(8.56,4.50; P<0.05) treated were higher than the untreated;whereas,The high quality oocyte rates(72.6%,79.2%;P>0.05)were not significantly different between the two groups.3.The differences of oocytes taken by OPU in heifers or dairy cattle.The average number of oocytes(5.89,4.41;P>0.05)and high quality oocyte rates(78.2%,72.3%;P>0.05)were not significantly different between the two groups.4.The differences of oocytes taken by OPU in healthy and not healthy dairy cattle.There were significantly different in recovered oocytes(5.92,3.88;P<0.05)and high quality oocyte rates(81.1%,69.9%;P<0.05)between the two groups.5.Dairy cattle oocytes collected repeatedly and once.There were no significant differences in recovered oocytes(5.16,5.80;P>0.05)and at high quality oocyte rates(80.6%,84.5%;P>0.05)between the two groups.Study of IVF:1.IVF with oocytes from OPU and slaughterhouse.The results showed that cleavage rates(77.6%,81.3%;P>0.05)and blastocyst rates(25.5%,29.2%;P>0.05)were not significantly different between the two groups.2.The sperm were treated by percoll and upriver.There were no significant differences at cleavage rates(80.7%,73.7%;P>0.05)and blastocys rates(27.6%,19.7%;P>0.05)between the two groups.3.The effects of different culture systems(SOF,BO)on IVF of dairy cattle.The cleavage rates(82.0%,77.9%;P>0.05)and blastocys rates(31.1%,26.7%;P>0.05)in SOF were not significantly different between the two groups.4.Cleavage rates were(83.6%,79.2%,75.7%;P>0.05)respectively at the fertilization time 8h,10h and 12h.There were no significant differences between the three groups.The blastocyst rates at 8h were higher than at12h(30.3%,19.6%;P<0.05)。But the blastocyst rates were not significantly different between 8h and 10h(30.3%,26.4%;P>0.05)and between 10h and 12h(26.4%,19.6%;P>0.05).5.The different oocytes number added to fertilization dripping(20,40).The results showed that the former cleavage rates(82.0%,70.5%;P<0.05)and blastocyst rates(31.0%,21.5%;P<0.05)was higher than the latter.