الفهرس 
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Abstract
SUMMERY
In the livestock species the IVEP efficiency percentage that estimated from proportion of the ability of oocyte to achieve the blastocyst stage is still limited. Moreover, the ovaries from abattoir were associated with essential factors that may affect oocyte competence.
Therefore, the study was conducted in the Animal Production Department at Faculty of Agriculture; Ain Shams University during 2020 and 2021. Ovaries collected from slaughterhouse we’re divided into five groups according to ovarian structure. An ovaries that containing CL were classified into mature corpus luteum (MCL), new corpus luteum (NCL) and large follicle + corpus luteum (LF+CL) groups, and that had follicular were divided according to diameters into large follicle (≥6mm), and small follicle (≤6mm) sizes. And for the 2ed experiment ovaries were classified for four groups B1, B2, B3 and B4 as patches collected per day.
The study was designed to evaluate the effect of ovarian patches and structures on in-vitro embryo production in cattle with the aims to:
(1) Investigate the proper abattoir ovarian structure that are associated with high oocyte quality and
(2) Identify the different factors that affect the IVEP and that may be associated with ovarian patches brought from abattoir.
Total of 1744 oocytes were recovered by aspiration technique from 568 cow’s ovaries obtained from the local slaughterhouse. The ovarian structures and patches groups were evaluated on the oocytes collection rate and its subsequent development.
The oocytes after culturing for 24 hours were examined under stereomicroscope for cytoplasmic maturation and determining oocyte that has expanded cumulus cells.
Total of 646 cow’s embryo were obtained and checked for the kinetic rate of cleavage. The cleavage rate was determined starting from incidence of fertilization day up to the blastocyst stage.
The result obtained from this study can be summarized as follows:
1- The collected oocytes numbered 274, 230, 94,103 and 171 from ovaries had SF, LF, NCL, MCL and LF, respectively.
2- The number of oocyte collected per ovary from the ovarian structure categories were arranged between 4.6 -2.1 oocyte per ovary with no differences found between the groups.
3- The numbers of in-vitro matured oocyte were significantly (p<0.0001) higher in SF 253 and LF 205 as compared to 148, 85 and 70 from LF+CL, MCL and NCL ovaries, respectively.
4- No significant variation were detected between maturation percentage of oocytes collected from all the groups, that ranged between 92.3% in ovaries that had small follicles and 74.5% in ovaries containing new CL (P< 0.0683).
5- The number and percentage of oocytes fertilization were similar among the studied groups, as well as the percentage of fertilized oocytes.
6- The cleavage to 2 cell embryo percentage after 48 hrs. embryo cultured were greater in ovarian groups that had NCL 47.87% and LF+ CL at 36.08 % as compared to that with SF, LF and MCL groups 16.48, 11.89 and 10. 21 %, respectively.
7- After 48 hours culture, the cleavage to more than two cells embryo percentages showed non-significant (p<689) different between the evaluated groups.
8- The cleavage to more than 2 cells embryo after 72 hrs. embryo culture showed high percentage cleavage in oocyte collected from ovaries having SF 51%, LF 48% and followed by LF+ CL 43% than those collected from ovaries with NCL and MCL groups 26 and 21% respectively.
9- The percentage of embryo development to morula embryo stage after 96 culture was higher (P<0.001) in ovaries containing SF 48% and LF 51% at 51% as compared with ovaries that had LF+CL, NCL and MCL at 39, 27 and 20% respectively.
10- The blastocyst stage development to hatching blastocyst embryo was affected by ovarian structure, and was found in ovaries with SF 2% and LF+CL 6% groups.
11- In the second experiment the largest numbers of oocytes collected were found in B1 309 followed by B2 130 and B4 130 oocytes. The lowest numbers of oocytes were recovered from the B3 303 oocytes.
12- The numbers of aspirated oocyte per ovary from different batches were not affected with the ovarian batches.
h and B3 257 ovaries as compared to that of the B2 121 and B4 111ovaries. The percentage of maturation oocytes were similar (P<0.0683) between the evaluated ovarian batches.
14- The greater number of the successes fertilized oocytes was achieved by B3 120 fertilized oocyte followed by groups of B1 99 and B4 84 fertilized oocyte, and the lowest result was recorded in group of B2 ovaries.
15- Variation were found in the percentage number of fertilized oocytes (P<0.001) among ovarian batches, the greater percentage of oocytes fertilization was observed in the B4 ovaries 76.58 % followed by B2 64.63%, as compared with that of B3 and B1 groups at 46.06 and 36.40, respectively.
16- The present study did not detect any variation in cleavage to 2 cells number between the evaluated groups after 48 hrs. culture.
17- After 48 hrs. culture, the highest percentage of cleavage to 2 cells embryo was observed in the B1 44.44 % group followed by groups B4 and B3, while the lowest result were achieved by B2 35.29%.
18- The embryo cleavage number to more than 2 cells after 48 hrs. culture was influenced by ovarian batches. The greater number of cultured oocyte cleavage to more than 2cells embryo stage were found in the group of B3 55% followed by B4 43% than the lower results that recorded in B2 and B1 at 36% and 30%, respectively.
19- The embryo cleavage percentage to more than two cells embryo after 48 hrs. culture was affected by ovarian batches, the highest cleavage were shown in B3 46.75 % and B2 at 45.33 % than that of groups B4 40.00% and B1 groups 30.30%.
20- After 72 hrs. culture, the greater developmental embryos to morula stage were achieved by group B3 58% followed by group B4 at 51 % as compared with groups of B2 42% and B1 at 38%.
21- The percentage of morula embryo development stage was greater in group B3 54% followed by B2 47% than in groups B4 46% and B1 and 38% after cultured for 96 hrs.
22- The embryo blastocyst hatching were different (P<0.001) in all patches, the greater percentage of blastocyst hatched was recorded in B2 (5%) and lower in the ovaries of group B4, B3 and B1 groups 2, 1 and 1% respectively.
Conclusion
Generally the current study deducted that, the ovaries with SF and LF recorded high progress in the most traits followed by LF+CL than the ovaries with NC and MCL which indicated the negative effect of CL+ on the evaluated traits.
However, the efficiency of in vitro embryo production can be achieved by collecting oocytes from ovaries without corpus luteum. Therefor the ovarian structure (follicles sizes and CL at different stage of development) of the slaughtered animal’s ovaries may serve as starting point for more effective quality oocytes for improving the efficiency in vitro embryo production technology. Also the current study concluded that most traits of the 2nd experiment were affected by ovarian batches this finding, may explain the effect of other various factors that are associated with the donor cattle from abattoir, seasons and Laboratory procedures. Finally, there were contradictions between different research in the impact of presence or absence of CL and follicle size to raise oocytes competences. So the author recommended that the IVP techniques still require more efforts to identify the causes of variation between different laboratories or to support the developmental of in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro culture (IVC) to blastocyst stage so to overcome the limitations.