Undergraduate Honors Thesis Projects

Date of Award

Spring 2020

Document Type

Honors Paper

Degree Name

Equine Pre-Veterinary/Pre-Graduate Studies-BS


Equine Science


Steffanie Burk, PhD.

First Committee Member

Steffanie Burk, Ph.D.

Second Committee Member

Sheri Birmingham, DVM.

Third Committee Member

Michele Acker, Ph.D.


Equine, Welfare, Hay Net, Saliva, Cortisol, Forage

Subject Categories

Higher Education | Other Animal Sciences


Throughout its evolution, the Equus caballus, or horse, developed a physiological response to environmental alterations involving the synthesis and release of cortisol from the hypothalamic-pituitary-adrenal axis, to regulate blood glucose levels, vascular tone and hormone release throughout the body (Ambrojo et al., 2018). With a hypothesis that changing a horse’s feeding method can alter salivary cortisol levels, the aim of this research project was to determine if feeding forage to horses in slow-feeding haynets would significantly reduce acute cortisol salivary level fluctuations, which would be valuable to minimize horses’ stress and increase overall welfare. Two feeding methods were tested with 20 clinically healthy horses randomly assigned to two equal groups at Otterbein University’s Austin E. Knowlton Center for Equine Science: treatment N with daily forage presented in a slow-feeding hay net and treatment G with forage presented on the ground. Group 1 received treatment N on days 0-7 and treatment G on days 8-14 and Group 2 received treatment G on days 0-7 and treatment N on days 8-14, with forage removed 2.75 hours after presentation. One salivary sample of 200-1000 µl was collected per horse on testing periods (days 6,7,13 and 14) and a competitive enzyme-linked immunosorbent assay (ELISA) was used to quantify the concentration of salivary cortisol within each sample (Salimetrics LLC, State College, PA). The mean individual values of each horse between treatments were compared, with a mean difference of -0.075 ± 0.290 µl/dl. These values were non-significant at p