Growth hormone (GH) is obligatory for growth and development. But, there is controversy on the GH effect about reproductive processes of sexual differentiation, pubertal maturation, gonadal steroidogenesis, gametogenesis and ovulation. This study was conducted to investigate the effect of GH on estrus, ovulation and embryo implantation. The results obtained were as follows. GH stimulated to increase estrus rate (p<0.05), pregnancy rate (p<0.05), and total fetus number in mice treated for superovulation. Also, the correlation between GH and steroids, E2 and P4, at peri-estrus stage/ peri-ovulation stage/ peri-implantation stage of the superovulation-induced mice was examined. Consequently, GH co-injected with PMSG especially increased P4 level (p<0.05) at peri-estrus stage of superovulationinduced mice. In conclusion, GH co-treatment in superovulation system boosted the rate of estrus, pregnancy and total fetus by increasing progesterone level at peri-estrus stage of superovulation-induced mice.

ABSTRACT   INTRODUCTION   MATERIALS AND METHODS    Experimental Animals and Housing Conditions    Superovulation Treatment    GH Treatment    Estrus Evaluation    Pregnancy Evaluation    Analysis of Serum P4 and E2    Statistical Analysis   RESULTS    GH and Reproductive Traits in Superovulation-Induced Mice    GH and Serum E2 and P4 Levels in Superovulation-Induced Mice    GH and Steroids at Peri-Estrus Stage    GH and Steroids at Peri-Ovulation Stage    GH and Steroids at Peri-Implantation    Comparison of PMSG and PMGS+GH superovulation systems    GH and Fetus Number in Superovulated Mice   DISCUSSION    GH and Estrus in Superovulation-Induced Mice    GH and Pregnancy in Superovulation-Induced Mice   REFERENCES

• Young Gee Kim(School of Animal Science and Biotechnology, Kyungpook National University)
• Zae Young Ryoo(School of Animal Science and Biotechnology, Kyungpook National University)
• Young Sik Park(School of Animal Science and Biotechnology, Kyungpook National University) Corresponding author