Life Sciences Commons^™

Fertilization Characteristics Of Spermatozoa Collected From Bulls Grazing Tall Fescue Pastures, Jessica Pegan Harris

Masters Theses

Consumption of toxic endophyte-infected (E+) tall fescue pastures is known to have a negative impact on bull reproductive performance. Since decreased cleavage rates of embryos fertilized with spermatozoa from bulls grazing E+ tall fescue pastures have been observed in several studies using differing sets of bulls, technicians, pastures, and other methods of inducing tall fescue toxicosis (ergotamine tartrate), it is hypothesized that spermatozoa function from bulls grazing E+ is impaired in ways undetectable by gross semen examination.

During a three-month grazing study, 6 Angus bulls were utilized to determine the effects of grazing E+ tall fescue pastures on growth performance …

Effects Of Osteopontin Single Nucleotide Polymorphisms On Bull Semen Quality, Chance L. Williams

Graduate Theses and Dissertations

Two groups of bulls were utilized to evaluate if single nucleotide polymorphisms (SNP) in the Bos taurus OPN gene (GenBank accession # AY878328.1) promoter region were related to bull semen quality variables as evaluated by computer assisted semen analysis (CASA). Group 1 consisted of 19 Angus and Balancer bulls, ranging in age from 5 to 8 years, which were collected weekly during a 2-month period (July 15, 2010 through September 19, 2010). Group 2 consisted of 16 Brahman influenced (1/8 to 3/16 Brahman) bulls, mean age = 1.1 ± 0.1 year, that were collected monthly for a 7 month period …