Off-campus South Dakota State University users: To download campus access theses, please use the following link to log into our proxy server with your South Dakota State University ID and password.

Non-South Dakota State University users: Please talk to your librarian about requesting this thesis through interlibrary loan.

Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Dairy Science

First Advisor

Robert J. Baer


A control (C) diet and a fish oil (FO) diet were fed to 6 multiparous Holstein cows to determine how the incorporation of Menhaden fish oil in the diet would influence the fatty acid composition, especially the conjugated linoleic acid (CLA) and transvaccenic acid (TV A) content of milk and butter. The C diet consisted of a 50:50 ratio of forage to concentrate and the FO diet consisted of the C diet with 2% (on dry matter basis) added fish oil. Milk from the C diet contained higher concentrations of milk fat (3.37%) compared to the FO diet (2.29%). Cows fed FO compared to the C diet had concentrations of CLA, TV A, and unsaturated fatty acids (2.51, 0.68; 6.28, 1.42; and 41. 71, 30.4 7 g/100 g of fat, respectively). Butter made from the FO milk also had higher concentrations of CLA, TV A, and unsaturated fatty acids. The fat content of the C and FO butters was 81.4%. Penetrometer readings indicated the FO butters were softer at 4 and 20°C than the C butters. Acid degree values were higher in the FO compared to the C butters, however, they were within the acceptable levels. No difference was found in the flavor characteristics of milk and butter from cows fed the C and FO diets. Production of milk and butter with increased amounts of CLA, TV A, and other beneficial fatty acids should have a desirable impact on the health of consumers.

Library of Congress Subject Headings

Linoleic acid
Fatty acids in human nutrition
Fish oils as feed


Includes bibliographical references (pages 32-40)



Number of Pages



South Dakota State University


In Copyright - Non-Commercial Use Permitted