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Document Type

Thesis - University Access Only

Award Date

2011

Degree Name

Master of Science (MS)

Department

Dairy Science

First Advisor

Kenneth Kalscheur

Abstract

The objective of this study was to examine the effects of DEMP (All tech, Nicholasville, KY) in substitution for soybean meal on milk production, dry matter intake, rumen, and blood parameters of high producing dairy cows. Sixteen Holstein cows (twelve multiparous and four primiparous) with 93 ± 37 DIM were used in a 4 x 4 Latin square design with four 28 d periods. Cows were blocked by parity and production, with one square consisting of 4 animals fitted with rumen-cannulas. Basal diets were formulated for 16.1 % crude protein and 1.56 Meal NEL/kg and contained 40% corn silage, 20% alfalfa hay, and 40% concentrate mix. During each period, cows were fed one of 4 treatments: control (0 g/hd/d DEMP), 300 (300 g/hd/d DEMP), 600 (600 g/hd/d DEMP), and 900 (900 g/hd/d DEMP). Customized soybean meal (44% CP) was replaced by DEMP to attain iso-nitrogenous and iso-energetic diets. Dry mater intake showed a cubic effect, with treatments 3 00 and 900 showing the highest intake. Milk production was not affected by DEMP, whereas there was a trend for a quadratic response with 4% fat corrected milk and energy corrected milk. Mid and long-chain fatty acid concentrations increased quadratically which elicited similar effects on butterfat concentration and yield. Total solids percentage and yield, and milk urea nitrogen also showed a quadratic effect as DEMP in the diet increased. There were no effects on feed efficiency, or on milk protein and lactose percentage or yield. Non-esterified fatty acids concentration in blood ~id not differ between treatments, meanwhile, β-hydroxybutyrate and blood glucose increased linearly as DEMP in the diet increased. Dietary treatments had no effect on pH and on most ruminal volatile fatty acids concentrations, with the exception of isovalerate which decreased linearly. Rumen ammonia concentration decreased linearly meanwhile free amino acids, total amino acids nitrogen, and soluble proteins weighing more than 10 kilo Dalton (kDa) on rumen N fractionation showed a cubic response. There was a quadratic response in oligopeptides that weighed between 3 and 10 kDa, and peptides under 3 kDa when expressed as percentages of total amino acids and total nitrogen. There was a cubic effect on body weight, but no differences in body condition scores between treatments. It was concluded that the substitution of soybean meal with DEMP can improve milk and total solids production in high producing dairy cows consuming high forage diets.

Library of Congress Subject Headings

Dairy cattle -- Feeding and feeds
Proteins in animal nutrition
Rumen -- Microbiology

Description

Includes bibliographical references (pages 63-76)

Format

application/pdf

Number of Pages

90

Publisher

South Dakota State University

Rights

In Copyright - Non-Commercial Use Permitted
http://rightsstatements.org/vocab/InC-NC/1.0/

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