Introduction and Utilization of the Beef Cattle NRC and other Software

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Introduction and Utilization of the Beef Cattle
NRC and other Software

• Dr. Matt Hersom
• Extension Beef Cattle Specialist

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Next 4 Class Periods

• Background and Introduction to the Beef Cattle
  NRC program
• Overview of the program components
• Overview of the Capabilities
• Inputs and Decisions
• Running the program
• Oklahoma State Free Software
• OSUNRC
• Cowculator

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Nutrient Requirements for Livestock

• NRC Publication Addresses
• Energy
• Protein
• Stage of production
• Vitamin/Mineral
• Water
• Growth
• Feed characteristics
• Metabolic Disorders
• Requirement Tables
• Feed Nutrient Composition

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What is the NRC Program?

• Programs predict requirements
• Predict energy and protein allowable production
  for diet ingredients
• All programs use same requirement equations
• Allows for application over a wide range of
  conditions.
• Factorial approach to energy for gain/production

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NRC Background

• 1996 NRC was released with a train-the-trainer
• First time that NRC was released as a computer
  program
• Big leap forward
• Net Energy
• Metabolizable Protein

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What is the NRC Program?

• Incorporation of all of the equations developed
  in the text into a LOTUS 1-2-3 spreadsheet.
• Equations for estimation of performance and rumen
  function were developed from best science.
• Queries user for variables for specific input
  parameters.
• Allows for customization to specific situations.
• Requires an understanding of biological concepts.

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NRC Components

• Level One Ration Evaluator
• Uses tabular NEm, NEg and DIP to estimate
• energy/protein supply
• microbial growth
• N requirements for fermentation
• Level Two Rumen Simulation
• Predicts feed CHO and protein ruminal degradation
• Mechanistic approach to digestion/absorption
• microbial growth
• N requirements for fermentation
• Escape of CHO and protein to predict ME and MP
• Amino acid balances

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NRC Components

• Feed Library
• Editable list of feeds
• Table Generator
• Compute tables of nutrient requirements
• Diet nutrient density
• Rapid evaluation of a diet to meet requirements

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Applications

• Cow
• Replacement heifer
• Growing steer/heifer
• Finishing Cattle
• Breeding Bulls
• Estimate Performance
• Alter Management Factors

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Using the NRC

• What Doesnt the Program Address

• Personal Comments

• Water intake
• Least cost

• Ease of use
• Everyday application
• Alternatives

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Examination of Prediction Equations

• Net Energy Maintenance
• Shrunk bodyweight0.75
• Adjustments
• Breed
• Lactation
• Previous plane of nutrition
• Activity
• Lactation
• Cold stress
• Heat Stress

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Examination of Prediction Equations

• Net Energy Gain
• Adjustments
• Empty bodyweight
• Empty body gain
• Metabolizable Protein for Maintenance
• Shrunk bodyweight
• Metabolizable Protein for Gain
• Shrunk weight gain
• Retained energy

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Examination of Prediction Equations

• Dry Matter Intake
• Growing calves and yearlings
• Shrunk BW0.75
• Diet NEm
• Body Fat adjustment
• Breed
• Feed Additive
• Temp adjustment
• Mud adjustment

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Examination of Prediction Equations

• Dry Matter Intake
• Cows
• Shrunk BW0.75
• Diet NEm
• Temp adjustment
• Mud adjustment
• Milk production
• Grazing Adjustment

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Input Variables

• Units Metric or English
• Dry Matter / As fed
• Animal Type
• Age
• Sex
• BW
• BCS
• Mature BW
• Breeding System
• Breed

• Management
• Feed Additives
• Pasture
• NE adjuster
• Microbial Yield
• Environment
• Wind speed
• Prev/Current Temp
• Night Cooling
• Hair depth
• Hide
• Coat condition
• Heat Stress

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Working through the Program