Document Type

Thesis - Open Access

Award Date

2018

Degree Name

Master of Science (MS)

Department / School

Animal Science

First Advisor

Jeffrey E. Held

Keywords

canola meal, carinata meal, cattle, corn residues, digestibility, protein supplement

Abstract

Brassica carinata is an oilseed crop that requires a relatively short growing season and produces high crop yields. It is a great source for aviation biofuel, however it produces a large amount of waste that may be used as a protein supplement for cattle. We tested the effects of solvent- or mechanically-extracted carinata meal as a protein supplement to ad libitum ground or long-stem corn residue (i.e., corn plant left over from grain harvest) had on cow performance and digestibility. Fifty-six non-pregnant cows in 8 pens had ad libitum access to either long-stem or ground corn residue in addition to mechanically- or solvent-extracted carinata meal, canola meal (positive control), or no supplemental protein (negative control). Overall, change in body condition score (ΔBCS) was -0.6 ± 0.06 and was not affected by forage length or supplemental protein (P = 0.37). However, change in body weight (ΔBW) was greatest (P < 0.01) among cows fed canola meal, least among cows fed supplemental mechanically-extracted carinata meal or no protein, and intermediate among cows fed solvent-extracted carinata meal. Cows fed ground corn residue had less ΔBW (P < 0.02) cows fed long-stem corn residue. Carinata meal has a high concentration of glucosinolates, however the value of these chemical compounds can vary from processing methods. Due to the high level of glucosinolate concentration in mechanically- and solvent-extracted carinata meal (72.34 μmol/g DM and 16.51 μmol/g DM, respectively), which can impair thyroid function and cause other negative effects, levels of T3 and T4 were tested in cows. At d 56, T3 was greater (P = 0.05) in cows fed canola meal compared to negative control cows and carinata meal was different. Protein supplement type had no effect on T4, but T3 and T4 were less (P < 0.04) at d 28 and d 56 among cows fed ground corn residue compared to cows fed longstem corn residue. Total DMI was less among cows fed no supplemental protein, intermediate for cows fed mechanically- or solvent-extracted carinata meal, and a tended (P = 0.10) to be greatest among cows fed canola (positive control) meal. Furthermore, forage intake was greater (P < 0.01) in cows fed long-stem corn residue compared to cows fed ground corn residue. However, measures of total-tract DM, OM, NDF, and ADF digestibility were increased (P < 0.01) by more than 23% among cows fed longstem compared to ground corn residue. Carinata meal could potentially serve as a source of supplemental protein for cows as a solvent-extracted form, but apparently not mechanically-extracted.

Library of Congress Subject Headings

Cattle -- Feeding and feeds.
Brassica.
Oilseed plants.
Canola meal.
Proteins in animal nutrition.

Description

Includes bibliographical references

Format

application/pdf

Number of Pages

62

Publisher

South Dakota State University

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Rights Statement

In Copyright