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Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Dairy Science

First Advisor

David J. Schingoethe


Twelve lactating Holsteins, (9 multiparous and 3 primiparous) were used in a replicated 3x3 Latin square design to evaluate 3 protein supplements that varied in RUP and amino acid composition. Cows received either 44% solvent soybean meal, expeller soybean meal, or an animal vegetable blend as a protein supplement. The animal vegetable blend consisted of equal portions of protein from blood meal, corn gluten meal, meat and bone meal, and soybean meal. Diets contained 17.4, 17.8, and 17.8 % CP and 33.6, 41.3, and 43.2 % of CP as RUP. All diets contained 33.3% alfalfa haylage, 16.7% com silage and 50% of the respective concentrate mix. Data were collected wk 2 to 4 of each 4 wk period. Dry matter intake (22.9, 21.7, and 21.2 kg/d) was similar (P=.09) among treatments. Milk yields (33.4, 33.3, and 32.7 kg/d), 3.5% FCM (34.4, 34.4, 33.7 kg/d), fat (3.74, 3.77, and 3.73 %), and protein (2. 99, 2. 94, and 2. 94 %) were similar (P >.30) among diets. Uptakes of amino acids by the mammary gland were similar (P>.09) among treatments. Body weights (606.7, 608.0, and 607.9 kg) and body condition scores (2.88, 2.75, and 2.79) were similar over the course of the trial (P >.2). Varying degrees of protein degradability within the range of this study did not affect animal performance indicating that all of these protein supplements were adequate in supporting milk production with no contrary affect to the animal.

Library of Congress Subject Headings

Dairy cattle -- Feeding and feeds
Proteins in animal nutrition
Rumination (Digestion)


Includes bibliographical references (pages 57-67)



Number of Pages



South Dakota State University


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