Date of Graduation

8-2011

Document Type

Thesis

Degree Name

Master of Science in Animal Science (MS)

Degree Level

Graduate

Department

Animal Science

Advisor

Charles F. Rosenkrans

Committee Member

Rick W. Rorie

Second Committee Member

Michael L. Looper

Third Committee Member

Nick Anthony

Keywords

Biological sciences; Antioxidants; Bovine sperm; Bulls; Ergot alkaloids; Sperm motility

Abstract

The studies that comprise this thesis were performed in an attempt to identify and eliminate stressful conditions that may lead to infertility in the male bovine. The first project was performed to determine if ergot alkaloids directly affect bovine sperm motility. Percentage of motile spermatozoa was affected (P = 0.015) by a three-way interactions between time, concentration, and alkaloid. Ergotamine and dihydroergotamine decreased (P = 0.01) sperm motility in a concentration and time dependant manner and ergonovine had a minimal effect on overall sperm motility. The number of static spermatozoa also was affected (P < 0.01) by a three way interaction and increased as ET and DHET concentrations increased. Percentages of progressively motile and rapidly motile spermatozoa decreased (P < 0.01) in a two way interaction between alkaloid and concentration. Overall, sperm motility was decreased by ET and DHET. Furthermore, the qualities of motility as represented by progressive, rapid, path velocity (VAP), progressive velocity (VSL), track speed (VCL), beat frequency (BCF), lateral amplitude (ALH), straightness (STR), elongated, and area were decreased by those alkaloids. These data verify that ergot alkaloids commonly found in toxic tall fescue are detrimental to bovine spermatozoa. In the second study two antioxidants (alpha-tocopherol and ascorbic acid) were added to bovine sperm culture media and cryopreservation extender. The antioxidant capabilities of these two vitamins could help reduce free radical production and help preserve sperm viability. There was an interactive effect between ascorbic acid concentration and storage method on the bovine sperm motility characteristics: motile, progressive, rapid, track speed (VCL), and straightness (P < 0.05). A bull by ascorbic acid interaction (P < 0.05) was observed for motile, progressive, rapid, path velocity (VAP), progressive velocity (VSL), and VCL characteristics. Alpha tocopherol had no affects on sperm motility characteristics. Lipid peroxidation was affected (P < 0.01) by bull and ascorbic acid. Malondialdehyde concentrations for ascorbic acid treatments (0, 5, 10, 20 mM) were 3.25, 4.2, 2.96, and 2.15 ìM respectively. Results from the second study indicate that the addition of ascorbic acid may reduce sperm motility, but help prevent lipid peroxidation.

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