Author ORCID Identifier
Date Available
12-5-2017
Year of Publication
2017
Degree Name
Master of Science (MS)
Document Type
Master's Thesis
College
Agriculture, Food and Environment
Department/School/Program
Veterinary Science
First Advisor
Dr. Karen J. McDowell
Abstract
Kentucky 31 tall fescue (KY31) infected with the common toxic endophyte strains of Epichloё coenophiala produces toxic alkaloids that improve plant vigor, but cause numerous adverse effects in grazing animals. Researchers developed a variety of KY31 containing an alternative strain of E. coenophiala, termed novel endophyte (NE). Adverse health effects in mares have not been evaluated.
Experiments in this thesis tested the hypothesis that the NE pasture does not cause adverse effects typically associated with KY31. Specific aims were to: 1) compare forage ergovaline concentrations between KY31 vs NE pastures; 2) evaluate palmar artery diameters in mares grazing KY31, NE, or orchardgrass-bluegrass (OGBG) pastures; 3) determine mare serum prolactin, estradiol, and progesterone concentrations associated with ingesting each pasture type over time; and 4) measure foaling outcomes, including percentage of live foals, foal birth weights, and foal growth rates. In 2015, six nonpregnant mares grazed KY31, six pregnant mares grazed NE and six pregnant mares grazed OGBG pastures. In 2016, eighteen mares were used; six mares grazed each pasture type.
Study results showed that ergovaline did not appear to be produced by NE. Novel endophyte pasture did not have negative effects on palmar artery diameter, reproductive hormones, or foaling outcomes.
Digital Object Identifier (DOI)
https://doi.org/10.13023/ETD.2017.458
Recommended Citation
Taylor, Victoria A., "PHYSIOLOGICAL CHANGES ASSOCIATED WITH PREGNANT OR NONPREGNANT MARES GRAZING PASTURES OF ORCHARDGRASS-BLUEGRASS, KENTUCKY 31 TALL FESCUE INFECTED WITH EPICHLOË COENOPHIALA, OR KYFA9821 TALL FESCUE INFECTED WITH THE NOVEL ENDOPHYTE AR584" (2017). Theses and Dissertations--Veterinary Science. 33.
https://uknowledge.uky.edu/gluck_etds/33
Included in
Animal Sciences Commons, Large or Food Animal and Equine Medicine Commons, Plant Sciences Commons, Veterinary Toxicology and Pharmacology Commons
