한우 육질등급이 난포란의 배반포 체외생산에 미치는 영향

Correlation of Hanwoo (Korean Native Cattle) Carcass Classification and Oocyte Donor for Blastocyst Production In Vitro

These studies were conducted to establish the practical Hanwoo (Korean native cattle) improvement system through the combining of embryo transfer technology and confirming individual Hanwoo oocyte culture system and to investigate that correlation of Hanwoo carcass classification (intramuscular marbling) and oocyte donor for blastocyst production in vitro. In case of Hanwoo, the carcass meat quality grades were divided to grade $1^{{+}{+}}$, $1^{+}$, 1, 2, and 3 depends on fat distribution of longest muscle cross-sectional surface. As results, the numbers of follicular oocytes collected from individual fundamentally-registered Hanwoo yielded $1^{{+}{+}}$, $1^{+}$, 1, 2 and 3 meat quality were 9.5, 9.4, 8.5, 8.8 and 8.8 per ovary, respectively. The numbers of retrieval oocyte from follicles were significantly higher in the cattle yield $1^{{+}{+}}$, $1^{+}$ meat quality than in the cattle yield 1, 2 and 3 meat quality (p<0.05). The rates of blastocyst formation were 18.2, 21.3, 29.4, 30.9, and 31.5% in the cattle yield $1^{{+}{+}}$, $1^{+}$, 1, 2 and 3 meat quality of after in vitro maturation, respectively. It was significantly lower in the cattle yield $^{{+}{+}}$ and $1^{+}$ meat quality than in the cattle yield 1, 2 and 3 meat quality (p<0.05). In order to evaluate embryos quality, TUNNEL assay was conducted for each meat quality grade using blastocyst stage embryo on day 8. The results showed that apoptosis cell number was higher tendency in the cattle yield $1^{{+}{+}}$and $1^{+}$ meat quality (81 and 79, respectively) than in the cattle yield 1, 2 and 3 meat quality (51, 48 and 50, respectively) but there was no statistical significance in each group. After embryo transfer, the conception rate of recipient was 53.5 (23 out of 43), 52.1 (38 out of 73) and 58.0% (58 out of 100) in the meat quality of 1, $1^{+}$ and $1^{{+}{+}}$, respectively. These results showed that the conception rate was significantly higher in the cattle yield 1 meat quality than in the cattle yield $1^{{+}{+}}$, $1^{+}$, 2, and 3 meat quality (p<0.05). In summary, these results indicate that the application of confirming Hanwoo individual oocyte culture system and embryo transfer technology can make good use of the genetic resources conservation and improvement of Hanwoo. Relevance of the meat quality grade and reproductive ability of carcasses of Hanwoo will be considered to be one of the effective means for the associated research with obesity and reproduction.