Related Experiment Video
Updated: Aug 8, 2026

Rodent Estrous Cycle Monitoring Utilizing Vaginal Lavage: No Such Thing As a Normal Cycle
Published on: August 30, 2021
Regulation of estrous cycles in dairy cattle: A review
1Department of Animal Science, University of Nebraska Lincoln, NE 68583-0908, USA.
Abstract:
Artificial insemination has allowed rapid genetic progress in dairy cattle through the use of semen from genetically superior sires. Detection of estrus and proper timing of insemination remain as major problems limiting reproductive efficiency in dairy herds. Numerous programs for regulating estrous cycles have been examined in this review. While several programs appear promising, results remain variable and the need for accurate detection of estrus has not been eliminated. Nulliparous heifers seem to respond more consistently than lactating cows. Further research is required to develop a successful program that will consistently produce a precise synchrony of estrus and ovulation with normal fertility and be cost effective.
Related Concept Videos
Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Hormonal Regulation
Ovarian Cycle
Regulation of Hormone Secretion
Humoral stimuli,...

