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Cereal Research Communications

, Volume 40, Issue 3, pp 405–412 | Cite as

Investigate the Magnitude of Differences on Total Metabolizable Protein among Different Genotypes of Barley Grown for Three Consecutive Years

  • K. J. Hart
  • B. G. Rossnagel
  • Peiqiang YuEmail author
Open Access
Article

Abstract

Several genotypes of barley have been developed by Crop Development Center. However, no quantitative evaluation of true protein supply to ruminants has been done in terms of protein degradation balance (PDB) and total metabolizable protein supply (or total truly absorbed protein in the small intestines). The objective of this study was to determine the magnitude of difference in terms of total metabolizable protein supply of five CDC feed-type barley cultivars in comparison to Canada’s most widely grown malting cultivar AC Metcalfe. Six, two row cultivars of spring sown barley, included AC Metcalfe, CDC Cowboy, CDC Dolly, CDC Helgason, CDC Trey and McLeod were grown in the research field of University of Saskatchewan, Saskatoon, SK, Canada for three consecutive years. The quantitative predictions were made in terms of: 1) Rumen synthesized microbial protein truly absorbed in the small intestine (AMCP); 2) Rumen undegraded protein truly absorbed in the small intestine (ARUP); 3) Endogenous protein in the digestive tract (AECP); 4) Total metabolizable protein supply in the small intestine. The results showed that CDC barley variety differed (P < 0.05) in AMCP ranging from 34 to 40 g/kg DMand AECP, but had no difference (P > 0.05) in ARUP with average of 48 g/kg DM. Total metabolizable protein ranged (P < 0.05) from 85 to 92 g/kg DM. In conclusion, CDC barley variety affected total predicted metabolizable protein supply, but not to large extend. All the barley varieties had negative degraded protein balance value.

Keywords

total metabolizable protein barley genotypes plant protein ruminants 

Abbreviations

ADIP

Acid detergent insoluble crude protein

AECP

Endogenous protein in the digestive tract

AMCP

Rumen synthesized microbial protein truly absorbed in the small intestine

ARUP

Rumen undegraded protein truly absorbed in the small intestine

CP

Crude Protein

D

Potentially degradable fraction in situ

ECP

Endogenous protein

EDCP

Effective degradability of crude protein in situ

Kd

Protein degradation rate in situ

Kp

Protein passage rate in situ

MCPEDCP

Potential Rumen synthesized microbial protein based on effective degradability of crude protein

MCPTDN

Potential Rumen synthesized microbial protein based on total digestible energy

MCPSupplied

Rumen synthesized microbial protein supply

MP

Metabolizable protein

NDIP

Neutral detergent insoluble crude protein

NPN

Non-protein nitrogen

PA

Fraction of CP that is instantaneously solubilized at time zero

PB1

Fraction of CP that is soluble in borate-phosphate buffer and precipitated with trichloroacetic acid

PB2

Calculated as total CP minus the sum of fractions PA, PB1, PB3 and PC

PB3

Calculated as the difference between the portions of total CP recovered with NDF and ADF

PC

Fraction of CP recovered with ADF and is considered to be undegradable. It contains proteins associated with lignin and tannins and heat-damaged proteins such as the Mailard reaction products

PDB

Protein degradation balance calculated based on data from NRC 2001 model

RUCP

Rumen undegradable feed protein

RUCPDVE

Rumen undegradable feed protein estimated according to the DVE/OEB system

S

Soluble fraction in situ

SCP

Soluble crude protein

TP

True Protein

U

Undegradable fraction in situ

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Copyright information

© Akadémiai Kiadó, Budapest 2012

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  1. 1.Department of Animal and Poultry Science HarperAdams University College NewportShropshireUK
  2. 2.Crop Development Centre, College of Agriculture and BioresourcesUniversity of SaskatchewanSaskatoonCanada

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