title: Progesterone in milk: a simple experiment illustrating the estrous cycle and enzyme immunoassay.
abstract: Experiments designed for students in reproductive physiology are rare. Here, we describe a simple experiment concerning a physiological aspect of the reproductive system. Milk samples are obtained from cows in estrus, in midcycle, 21 days after insemination, and in gestation. With these samples, the gestation or estrous stage is determined according to the progesterone level in milk that is measured using enzyme immunoassay. This experiment can therefore be used to demonstrate assay techniques and to illustrate the variations in progesterone concentrations during an estrous cycle and gestation. This exercise should be given after the reproduction section of the animal physiology course so that students can apply their knowledge concerning hormonal profiles during an estrous cycle.
authors.affiliation: Département de Biologie, de Chimie et des Sciences de la Santé, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, Quebec, Canada G5L 3A1. pierre_rioux@uqar.qc.ca
authors.forename: Pierre
authors.initials: P
authors.lastname: Rioux
authors.forename: Denis
authors.initials: D
authors.lastname: Rajotte
mesh_terms: D000818:Animals; D001695:Biology / Q000193:education; D002417:Cattle; D030762:Estrous Cycle / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D008892:Milk / Q000737:chemistry*; D010827:Physiology / Q000193:education*; D011374:Progesterone / Q000032:analysis*; D012098:Reproduction
chemical_list: D011374:Progesterone