Comparing the efficacy of EGTA and 5-HTP induction and resolution of hypocalcemia in dairy cows

PI: Laura Hernandez


Hernandez is a professor of animal and dairy sciences at UW–Madison specializing in lactation physiology. The overall goal of her research is to understand how autocrine/paracrine factors in the mammary gland regulate mammary gland development, as well as milk synthesis and secretion.

Postdoc: Haylee Hanling (pictured above), an aspiring animal and dairy science professor, has an interest in lactation physiology. Through prior research assistantships Hanling was able to develop laboratory and surgical skills. She has assisted in udder-half mammary biopsies, provided post-operative wound care, and extracted milk mammary epithelial cells. Hanling will be mentored by Laura Hernandez from the Department of Animal and Dairy Sciences.

Hypocalcemia, which causes lethargy and death if left untreated, is a common and pervasive disease in the dairy industry. Research has shown that inducing transient hypocalcemia prepartum causes a resistance to the disease postpartum. 5-HTP, the precursor to serotonin, infusion prior to calving has been effective in this process. Five percent EGTA infusions also induce hypocalcemia but have never been administered prepartum. This research team aims to answer the following questions: 1) is 5-HTP more efficient than EGTA in inducing transient hypocalcemia prepartum and improving calcium concentrations postpartum? 2) What are the effects of EGTA and 5-HTP on endocrine functionality systematically and at the mammary cell level? To investigate the research team will infuse 24 Holstein cows with either 5-HTP, EGTA, or control saline for 7 days prior to their expected calving dates. Researchers will then analyze blood, milk, and mammary tissue. Blood samples will be taken during and after infusion to measure calcium concentrations, reproductive hormones, and immunity markers. Mammary biopsies taken postpartum will be analyzed for calcium transporters in mammary epithelial cells. These methods allow researchers to compare mechanisms of action of 5-HTP and EGTA in inducing and resolving hypocalcemia postpartum.

Haylee Hanling