Human chorionic gonadotropin manufacturer

　　1. Gonadotropin-releasing hormone (GnRH)

　　The use of GnRH and its analogues can induce oestrus ovulation in dogs, but the effect is not consistent. Some studies have shown that GnRH injection is only effective when follicles on the ovaries have developed to a certain extent. GnRH does not increase the number of growing follicles, but only promotes the ovulation of mature follicles.

　　2.Gonadotropin

　　Gonadotropin has been widely used to induce estrus in dogs. These hormones are effective in stimulating follicle growth and ovulation in dogs. Due to the short half-life and high price of FSH and LH, placental gonadotropin PMSG and human chorionic gonadotropin HCG are commonly used in production practice. Analysis of the reasons for the different effects after use suggests that, firstly, it may be due to the different number of developmental follicles that can respond to hormone treatment; secondly, it may be related to the different response of the tested dogs to hormone; thirdly, it may be related to the different response of the tested dogs to hormone treatment. And finally, of course, it may have something to do with the quality of the hormones used. In addition, PMSG combined with HCG can be used to induce estrus in female dogs, especially those who have been in heat. However, the rate of oestrus induction and ovulation was only 20%, far lower than that of natural oestrus. This may be due to the use of exogenous hormones to shorten the normal maturation of follicles, resulting in follicle growth and development of insufficient and affected the quality of gametes. In addition, most of the females treated with the combination of the two have abnormal lutein P4 level and insufficient lutein function, thus unable to maintain the normal pregnancy.