Practical Beef Nutrition and Ration Formulation

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Practical Beef Nutrition and Ration Formulation

• Dan Loy
• 301 Kildee
• dloy_at_iastate.edu

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Basic Outline

• Nutrient Requirements of Importance
• Adjustments to Requirements (beef cows)
• Heifer development
• Adjustments to Requirements (feedlot)
• Introduction to BRANDS
• Common Nutritional problems (time permitting)

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Nutrient Requirements of Importance

• Energy
• Protein
• Major Minerals
• Minor Minerals and Vitamins

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PARTITIONING OF ENERGY
Gross Energy (GE) Digestible Energy
(DE) Metabolizable Energy (ME) Net Energy
(NE)
Digestion loss (fecal)
Urine loss Combustible gases (CH4)
Heat increment (HI) -heat of fermentation -heat
of nutrient metabolism
NEm -basal metabolism -activity at
maintenance -sustaining body temp
NEg -retained energy
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Net Energy for Production

• Weight Gain
• Lean vs. Fat
• Body Condition gain
• Fetal Growth
• Milk Production

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Net Energy for Maintenance

• Basal Metabolism
• Environmental adjustments

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Metabolizable Protein
bypass
CP
UIP
energy (TDN)
MP
DIP (ammonia)
MCP
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Effect of Weight and ADG on Protein Requirements
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Major Minerals

• Calcium
• Required for milk production and growth
• Grains are low in Ca, Forages are high in Ca
• Phosphorous
• Required for milk production and growth
• Grains and corn coproducts are high in P, and low
  in Ca
• CaP may be important in steers because of
  urinary calculi

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Major Minerals cont

• Magnesium
• Low in lush spring grassGrass Tetany is a common
  deficiency
• Salt
• Sodium requirement, most feeds are low in sodium
• Potassium
• High in forages, low in grains.
• Sulfur
• Needed when urea is added. Toxicity is concern

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Trace Minerals and Vitamins

• Trace Minerals for Beef Cattle
• Co, Cu, I, Fe, Mn, Se, Zn
• Should be part of sound mineral supplementation
  program
• Regional differences
• Vitamin Requirements
• Vitamin A, D, E. Some B vitamins may be needed
  for stressed calves.

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Adjustments to Requirements (cows)

• Stage of Production
• Environmental Adjustments
• Cow size and breed
• Body Condition Scoring

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Seasonal Beef Cow Energy Requirements
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Seasonal Beef Cow Protein Requirements
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EFFECT OF ENVIRONMENT ON ENERGY REQUIREMENTS
Lower Critical Temperature
Upper Critical Temperature
THERMONEUTRAL ZONE
Cold stress
Heat Stress
Optimum for Performance and Health
High
Low
EFFECTIVE AMBIENT TEMPERATURE
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Lower Critical Temperature

• Coat Description LCT
• Summer or wet 59
• Fall 45
• Winter 32
• Heavy winter 18

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Effective Temperature
Temperature Wind Speed -10 0 10 20 30 Calm -10 0
10 20 30 5 -16 -6 3 13 23 15 -25 -15 -5 4 14 30 -
46 -36 -26 -16 -6
Maintenance Requirements increase .7 for each
degree of cold stress.
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Environmental Adjustments NRC

• Added are
• Internal insulation factors (body condition or
  fatness)
• Hide thickness
• Heat production from feed

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Effect of Breed on Energy Requirements
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Effect of Lactation on Energy Requirements
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Body Condition Scoring

• Management tool for adjusting energy requirement
  of beef cows
• Also used to evaluate previous nutrition of
  feeder cattle

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Thin Cows

• 1  Severely emaciated starving and weak no
  palpable fat detectable over back, hips or ribs
  tailhead and individual ribs prominently visible
  all skeletal structures are visible and sharp to
  the touch animals are usually disease stricken.
  Under normal production systems cattle in this
  condition score are rare.
• 2  Emaciated similar to BCS 1, but not weakened
  little visible muscle tissue tailhead and ribs
  less prominent.
• 3  Very thin no fat over ribs or in brisket
  backbone easily visible, slight increase in
  muscling over BCS 

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Borderline and Optimum

• borderline
• 4  Borderline individual ribs noticeable but
  overall fat cover is lacking increased
  musculature through shoulders and hindquarters
  hips and backbone slightly rounded versus sharp
  appearance of BCS 3.
• optimum
• 5  Moderate increased fat cover over ribs,
  generally only 12th and 13th ribs are
  individually distinguishable tailhead full, but
  not rounded.
• 6  Good back, ribs, and tailhead slightly
  rounded and spongy when palpated slight fat
  deposition in brisket.

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Fat Condition

• 7  Fat cow appears fleshy and carries fat over
  the back, tailhead, and brisket ribs are not
  visible area of vulva and external rectum
  contain moderate fat deposits may have slight
  fat in udder.
• 8  Very fat squared appearance due to excess fat
  over back, tailhead, and hindquarters extreme
  fat deposition in brisket and throughout ribs
  excessive fat around vulva and rectum, and within
  udder mobility may begin to be restricted.
• 9  Obese similar to BCS 8, but to a greater
  degree majority of fat deposited in udder limits
  effective lactation. Under normal production
  systems cattle in this condition score are rare.

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Condition Scoring Examples

• Condition Score 3
• Condition Score 6
• Condition Score 8

Pictures from NDSU factsheet AS-1026
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Condition Scoring of Cows

• Optimum is condition 5-6 at calving
• Each condition score it 80 to 150 pounds
  depending on cow size
• It is best to condition score cows in the fall to
  allow sufficient time for condition score gain

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Heifer Development

• Target Weight Concept
• Heifers should be 60 of mature weight at
  breeding and 85 of mature weight at calving
• Sets target weights and rate of gain
• 1400 mature size should weigh 840 at breeding
  and 1190 at calving. If fall weight is 500 lb.,
  in November (210 days before breeding), then ADG
  needs to be 1.6 to breeding.

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Adjustments to Requirements (feedlot)

• Frame size
• Implants
• Feed additives
• Step up programs
• Bunk Management/Monitoring

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Frame Size
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Weight at 28 Body Fat
Frame Size Frame Size Frame Size Frame Size Frame Size Frame Size Frame Size Frame Size Frame Size
1 2 3 4 5 6 7 8 9
Steer 882 954 1029 1102 1175 1250 1322 1395 1470
Heifer 705 763 824 882 939 1001 1058 1115 1177
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The Normal Growth Curve
Management for more rapid growth changes the shape
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Muscle Growth
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Fat Growth
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Methods of Increasing Grain
Ration Step
Concentrate Intake
Concentrate
Feed Intake
X

Days
Days
Days
Increasing Grain
Feed Intake
Concentrate Intake
X
Concentrate

Days
Days
Days
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Feed Additives for Feedlot Cattle

• Ionophores
• MGA
• Optaflexx
• Broad spectrum antibiotics
• Coccidiostats

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Adapting cattle to grain

• Two parts
• Manage feed consumption
• Adjust rumen microbes to new substrate
• Each may take 2-3 weeks with calves
• May only take 4 weeks with previously adapted
  yearlings
• Thumb rule for initial grain consumption
• .5 to 1 of bodyweight

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Developing a Starting Program (some examples)

• determine expected intake
• determine eventual ration
• determine beginning concentrate levels

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Sample starting program - Long hauled calves (
400 lb.)
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Sample starting program - precon or low stress
calves (400 lb.)
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Sample starting program - Backgrounded yearlings
(800 lb.)
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Goal of Feedbunk Management

• Deliver a consistent, nutritious, fresh ration in
  a manner that maximizes feed intake and minimizes
  waste and spoilage.

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Some Items a Good Bunk Sheet Should Contain

• Pen Number
• Lot Number
• Head Count
• In Weight
• Current Weight
• Days on Feed
• Days on Ration

• Indication of Slick Bunks
• Indication of When Bunks Last Cleaned
• Amount of Feed Fed Last 5-7 Days

From Horton (1990)
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SDSU Bunk Scoring System

• Developed to improve feed deliveries in a
  University Research Feedlot
• Improved efficiency
• Uses a 4-Point Bunk Scoring System

From Pritchard (1993)
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SDSU 4-Point Bunk Scoring System
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Bunk Score 0 to 1/2
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Bunk score 1 and 2
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Example Bunk Sheet
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Making Feed Calls

• Cattle Aggressiveness
• 25-50-25 Rule
• Weather
• Heat
• Mud
• Rain
• Cold
• Storm Rations?

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Other Bunk Mgmt Factors

• Feed presentation
• Mixing
• Processing (particle size)
• Fines (conditioners)
• Nutritional Adequacy

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Bunk Management Philosophy
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Bunk Management Philosophy
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Cumulative Performance of Prescription Fed Cattle
Treatment Item
Prescription Ad libitum Cumulative (121
days) BW 1328
1331 ADG
3.84 3.85 DMI
23.57 26.39 F/G
6.15 6.90 Frequency of
slick 69.3 39.7 bunks,
Pritchard, 1997
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Beef Nutrition via the BRANDS Software Package

• Drs. Daryl Strohbehn and Dan Loy
• Extension Beef Specialists

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What is BRANDS?

• BRANDS is a series of spreadsheet programs which
  work in conjunction with Microsoft Excel to
  assist producers and beef professionals in
  balancing rations for all types of cattle.
• BRANDS features 5 ration modules.

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• Feedlot
• Beef Cow
• Heifer
• Growing Bull
• Breeding Bull

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programmed using
Nutrient Requirements of Beef Cattle Seventh
Revised Edition Update 2000
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Comes in two different types of
packagesStandard Edition Modules For the
beginner (Excel 5.0 beyond)Professional
Edition For the experienced nutritionist that
has multiple clients (Excel 2000 beyond)
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Introduction Screen-BRANDS Professional
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Feed Library Worksheet
Common Feed Library Shared Between Modules
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Cow Module- Professional Edition Input Screen
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Ration Balancing Screen
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Feedyard Module
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Feedyard Module- Professional Edition Input Screen
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Heifer Module
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Heifer Module- Professional Edition Input Screen
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Calendarized Heifer Development Screen
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Nutritional Problems in Beef Cattle

• Grass Tetany
• Urinary Calculi
• Sulfur Toxicity (polioencephalamalacia)
• Se deficiency
• Acidosis and Bloat
• Nitrate and urea toxicosis
• Molds and mycotoxins