Theses and Dissertations

Issuing Body

Mississippi State University


Morrison, Jesse I.

Committee Member

Karisch, Brandi B.

Committee Member

Baldwin, Brian S.

Committee Member

Parish, Jane A,

Date of Degree


Original embargo terms

Visible to MSU Only 3 Years

Document Type

Graduate Thesis - Campus Access Only



Degree Name

Master of Science


College of Agriculture and Life Sciences


Department of Plant and Soil Sciences


Annual ryegrass (Lolium multiflorum Lam.) can be divided into two cytotypes: diploid (2n = 2x = 14) or tetraploid (2n = 4x = 28). Transforming annual ryegrass from diploid to tetraploid often results in increased seedling vigor, more robust growth and, thus, supposedly greater yield. There has been conflicting research that suggests no difference in yield between diploid and tetraploid cultivars, but livestock producers’ question whether benefits exist to utilizing tetraploid cultivars for grazing cattle. This study sought to determine if annual ryegrass cytotype affected cattle average daily gain. Although there were no differences in average daily gain between cytotypes, there were differences among cultivars. In 2017, Jumbo (4x) produced the greatest weight gain, while in 2018, Tam-90 (2x) generated the greatest gain. This study suggests that there are no advantages attributed to average daily gain by utilizing tetraploid, as opposed to diploid cultivars.