Reproductive Hormones Share
The cattle estrus cycle is a cycle of endocrine events associated with morphological changes in the cow's reproductive tract accompanied with certain behavioral traits.
Cows receive estrus in a carefully regulated cycle, which gives repeated opportunities to the animals to become pregnant. It is regulated by the hypothalamic-pituitary-gonadal (ovary) axis producing hormones that dictate reproductive events in cattle.
Female Cow Hormones: Description and Function1
|Hormone||Source||Target tissue||Primary action|
|Gonadotropin Releasing Hormone (GnRH)||Hypothalamus||Anterior lobe pituitary||Release of FSH and LH from anterior lobe pituitary|
|Follicle Stimulating Hormone (FSH)||Anterior lobe pituitary||Ovary (granulosa cells)||Follicular development, estradiol synthesis|
|Luteinizing Hormone (LH)||Anterior lobe pituitary||Ovary (theca interna and luteal cells)||Stimulates ovulation, formation of corpus luteum and progesterone secretion|
|Estradiol (E2)||Ovary (follicle), placenta||Hypothalamus, entire reproductive tract, mammary gland||Sexual behavior, elevates secretory activity of the entire tract, enhances uterine motility|
|Oxytocin||Hypothalamus and placenta, synthesized by CL||Myometrium and endometrium uterus, mammary gland||Uterine motility, promotes uterine PGF2α secretion, milk ejection|
|Progesterone (P4)||Corpus luteum, placenta||Uterine endometrium, hypothalamus, mammary gland, myometrium||Endometrial secretion, inhibits GnRH release, inhibits reproductive behavior, promotes maintenance of pregnancy|
|Prostaglandin F2α (PGF2α)||Uterine endometrium||Corpus luteum, oviduct||Luteolysis, promotes uterine tone and contraction, ovulation|
- Senger PL. Pathways to pregnancy and parturition. 2005. ISBN:978-0965764827