Document Type

Dissertation - Open Access

Award Date

2016

Degree Name

Doctor of Philosophy (PhD)

Department

Dairy Science

First Advisor

David P. Casper

Keywords

dairy, dairy cattle, forage quality, high forage, nutrition, production

Abstract

Three studies were conducted to determine production parameters and study specific hypothesis in regard to improving feed efficiency through various forage utilization strategies with or without the inclusion of various supplemented products. The first study evaluated the supplementation of a cobalt-lactate product and its effects on fiber digestibility and milk production parameters when fed to cows consuming a 70% forage diet. Treatments included: 1) CONTROL diet containing 12.5 mg/cow/d of cobalt (carbonate carbonate) and 2) TEST diet being the same basal diet but including an additional 50 mg/cow/d of cobalt via a 1% Co-lactate product (Co-Max®). In a feeding trial with 24 late lactation cows, feeding the cobalt-lactate product had no effect on production parameters. However, cobalt-lactate supplementation decreased rumen ammonia concentrations, increased ruminal molar concentrations of acetate and numerically increased fiber digestion. The second study evaluated Saccharomyces cerevisiae fermentation products (SCFP); (Diamond V original XPC and two prototypes) on lactational performance and ruminal fermentation. Eight ruminally cannulated Holstein dairy cows were used in a replicated 4 x 4 Latin square. Treatments were: 1) Control (C): corn silage and haylage based ration; 2) XPC: C ration with 14 g/hd/d Original XPC; 3) Prototype 1 (P1): C ration with 5 g/hd/d P1; and 4) Prototype 2 (P2): C ration with 19 g/hd/d P2. Ruminal pH (6.06, 6.07, 6.02 and 6.13 for C, XPC, P1, and P2 respectively) was greater (P < 0.05) for cows fed P2 compared to cows fed other treatments. Rumen concentration and percentage of propionate and iso-butyrate were increased (P < 0.05) for cows fed P2 when compared to C with cows fed other treatments being intermediate and similar. The feeding of a dairy ration with P2 SCFP can improve ruminal pH while increasing propionate and iso-butyrate concentrations and percentages. The third study evaluated two forage production programs with subsequent feeding to evaluate the lactational performance of Holstein dairy cows. Thirty peak-lactation (58 DIM ± 2.9) Holstein dairy cows were used in a randomized complete block design. Treatments were: 1) CONTROL: normal forages (65% of diet) ration formulated using alfalfa haylage and corn silage produced with a standard university soil and agronomy program; 2) TEST: high forage level (65% of diet) ration formulated using alfalfa haylage and corn silage produced on an enhanced soil and agronomy program. Milk production was increased for cows fed TEST compared to cows fed control forage while DMI were similar. Energy corrected milk was increased for the TEST fed cows. There was an increasing trend in starch digestibility for cows fed TEST forage. Digestibility of NDF and ADF were increased for the TEST fed cows compared to cows fed CONTROL forages. Feeding higher quality forages obtained from enhanced agronomy procedures increased milk production, milk composition, and fiber digestibility when lactating dairy cows were fed a high forage ration. Based on these results, lactating dairy can greatly benefit from increases in forage quality and forage digestibility. Supplemental products such as SCFP can be utilized to aide in increases in propionate production which typically lead to increases in milk yield.

Library of Congress Subject Headings

Dairy cattle -- Feeding and feeds

Dairy cattle -- Feed utilization efficiency

Forage

Description

Includes bibliographical references (page 89-107)

Format

ap

Number of Pages

120

Publisher

South Dakota State University

Rights

Copyright © 2016 South Dakota State University

Included in

Dairy Science Commons

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