Date of Award:

12-2026

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Animal, Dairy, and Veterinary Sciences

Committee Chair(s)

S. Clay Isom

Committee

S. Clay Isom

Committee

Kara Thornton-Kurth

Committee

Lee Rickords

Abstract

Pasture-based dairying is important to organic milk production, but young heifers differ in how well they eat, grow, and adapt to grazing. This study tested whether commercial genetic information could help identify which heifers would perform best on pasture. Genetic samples from 139 Holstein, Jersey, Holstein-Jersey, and ProCross heifers raised on organic pastures in northern Utah were analyzed with the Neogen Igenity Select test and compared with measurements of feed intake, growth, and grazing performance. Genetic scores clearly separated the breed groups, but they were not strong predictors of how individual heifers grew on pasture. Pasture quality, especially forage nutrient composition, explained much more of the variation. Predictions improved when genetic information was combined with forage data. These results show that genetic testing can contribute useful information for pasture-based heifer management, but it is most informative when considered together with the quality of the pasture environment.

Download

Included in

Dairy Science Commons

Share

COinS

Copyright for this work is retained by the student. If you have any questions regarding the inclusion of this work in the Digital Commons, please email us at .