Final answer:
The estrous cycle of cattle consists of proestrus, estrus, metestrus, and diestrus phases, regulated by hormones such as estrogen and progesterone that peak at different phases to facilitate mating, ovulation, and maintenance of pregnancy conditions.
Step-by-step explanation:
The estrous cycle of cattle is the reproductive cycle experienced by female cattle, which prepares them for pregnancy. It is divided into different phases: proestrus, estrus (heat), metestrus, and diestrus. Estrogen levels rise during the proestrus phase leading to estrus, when ovulation occurs. After ovulation, during the metestrus and diestrus phases, progesterone produced by the corpus luteum dominates, making the environment suitable for potential embryo implantation. If the cow does not become pregnant, the cycle restarts with a decline in progesterone levels.
Hormonal Regulation in Estrous Cycle
The hormones involved in this cycle include estrogen, progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Estrogen peaks during estrus, causing behavioral changes signaling readiness to mate. Progesterone rises after ovulation, maintaining pregnancy conditions. LH and FSH from the anterior pituitary gland regulate the cycle, with LH being crucial for ovulation and FSH for follicle development.
The blood concentration patterns of these hormones follow the phases of the estrous cycle, with estrogen peaking during estrus and progesterone peaking during the luteal phase (metestrus and diestrus). The precise control of these hormone levels is crucial for successful reproduction in cattle.