Balancing Rations

1
Balancing Rations

• Animal Science II
• Unit 8

2
Objectives

• Classify feeds as roughages and concentrates
• Describe the six functions of a good ration
• Explain the characteristics of a good ration
• Balance livestock rations using commonly accepted
  practices

3
Classification of Feeds
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Roughages

• Contain more than 18 crude fiber when dry
• Includes hay, silage, pasture, fodder
• 2 general class legume roughage and non-legume
  roughage

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Legume Roughages

• Can take nitrogen from the air
• Able to due so because they have nodules on their
  roots that contain bacteria
• These bacteria fix the nitrogen from the air in
  soil and make it available for the plant to use
• Do so by combining the free nitrogen with other
  elements to form nitrogen compounds
• All the clovers, alfalfa, soybeans, trefoil,
  lespedeza, peas and beans
• Usually higher in protein than nonlegume roughages

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Nonlegume Roughages

• Cannot use nitrogen from the air
• Lower in protein
• Many common livestock feeds are nonlegume
• Corn silage, sorghum silage, fodders, bluegrass,
  timothy, redtop, bromegrass, orchardgrass,
  fescue, costal Bermuda grass, common Bermuda
  grass, prairie grass (Western wheatgrass,
  Kentucky bluegrass, etc)

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Concentrates

• Less than 18 crude fiber when dry
• Two classes
• Protein supplements
• Energy feeds

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Protein Supplements

• 20 or more protein
• Divided into 2 groups based on their source

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Protein Supplements

• Animal proteins
• Come from animals or animal by-products
• Common tankage, meat scraps, meat and bonemeal,
  fish meal, dried milk (whole skimmed), blood
  meal, feather meal
• Most contain more than 47 crude protein
• More balanced essential amino acids
• Variable quality compared to vegetable proteins

• Vegetable Proteins
• Come from plants
• Common soybean oil meal, cottonseed meal,
  linseed oil meal, peanut oil meal, corn gluten
  feed, brewers dried grains, distillers dried
  grains
• Most contain less than 47 crude protein
• Soybean oil meal is used most
• Can supply necessary amino acids for swine and
  poultry
• Only protein source that can be used for
  ruminants

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Commercial Protein Supplements

• Made by commercial feed companies
• Mixes of animal and plant protein feeds
• Usually made for 1 class of animal
• Often mix of minerals, vitamins, antibiotics
• Feed tag needs to be read and feeding directions
  followed

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Energy Feeds

• Feeds with less than 20 crude protein
• Most grains
• Oats, corn, sorghum, barley, rye, wheat, ground
  ear corn, wheat bran, wheat middling's, dried
  citrus pulp, dried beet pulp, dried whey
• Corn is the most widely used
• Followed by sorghum grain, oats, barley

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Ration Characteristics
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Ration Characteristics

• Animals need proper nutrition to efficiently
  produce meat, milk, eggs, wool, work, etc
• A ration is the amount of feed given to an animal
  to meet its needs during a twenty-four hour
  period
• A balanced ration is one that has all the
  nutrients the animal needs in the right
  proportions and amounts
• Diet refers to the ration without reference to a
  specific time period

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Palatability

• Ration must taste good
• Mold, insect and weather damage all lower
  palatability

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Feed Economics

• Feed accounts for approximately 75 of the total
  cost of raising livestock
• Therefore it is necessary to develop rations that
  are as economical as possible

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Poisonous Plants

• Should not be included in the diet
• Sometimes grow in hay fields or pastures
• See Table 8-1 p.165

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Balancing for Species and Age

• Ruminants use more roughage than nonruminants
• Younger animals cannot use as much roughage
  either
• Also need to consider the purpose for which the
  animal is being fed
• For example fattening animals generally should be
  fed less roughage than breeding animals

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Micronutrients and Feed Additives

• Used in small quantities
• Care needs to be taken to thoroughly mix these
  for uniform distribution
• Excessive amounts of micronutrients can be
  harmful

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Functions of the Ration
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Functions of Rations

• Must be considered when determining nutrient
  requirements
• Functions include
• Maintenance
• Growth
• Fattening
• Production
• Work

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Maintenance

• Primary use of nutrients is to maintain life
• Animals must have energy for the functioning of
  the heart, breathing and other vital body
  processes or the basal metabolism
• Energy is also needed to maintain body
  temperature
• The ration must also provide protein, vitamins
  and minerals, fatty acids to replace those that
  are naturally lost
• About ½ of the ration fed is needed for
  maintenance
• An animal on full feed will use about 1/3 of the
  ration for maintenance

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Growth

• Nutrients can only be used for growth after
  maintenance requirements are met
• Animals mature by growing
• Larger species mature slower
• Growth rate of large animals is faster than that
  of smaller animals

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Fattening

• Nutrients that are not used for maintenance or
  growth may be used for fattening
• Fat is stored into the tissues of the body
• Fat within the muscle is called marbling
• Marbling makes meat juicy and good tasting
• The object of fattening is to obtain the right
  amount of fat in the muscle without getting too
  much fat
• Feeds that are high in carbohydrates and fats are
  used for fattening

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Production

• Cows, swine, horse, sheep, goats all produce milk
  to feed their young
• Dairy goats and cows produce milk for human use
  as well
• Chickens produce eggs
• Sheep and goats produce mohair
• All this production requires nutrients. The
  nutrients depend on the kind of production

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Reproduction

• Requires proper nutrition
• Animals may become sterile
• Extremely important for pregnant animals
• Most of the fetuss growth takes place during the
  last third of the pregnancy
• Additional amounts of nutrients are needed during
  pregnancy

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Work

• Horses-riding, driving
• Energy needed for work comes from carbohydrates,
  fats, extra protein
• Other needs of the body are met before nutrients
  are available for work
• Animal will use fat stored in the body for work
  if the ration does not supply enough
• Extra salt is also needed due to animals sweating

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Balancing Rations
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General Principals

• Must meet the nutritional needs
• Nutrient allowance should be met as close as
  possible
• Not more than 3 below the requirement

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Dry Matter

• Must have a certain amount in the ration
• If not the animal will be hungry
• The digestive system will not function properly
• Also an upper limit that varies with the animal
  being fed and its size
• Total dry matter in the ration of a full fed
  animal should not be more than 3 above its need

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Protein

• Measured by the total protein (TP) need of the
  animal
• Digestible protein may also be used to balance
  the ration
• Essential amino acids must be included when
  balancing a ration for nonruminants
• Acceptable to allow 5-10 more protein in the
  ration than the animal needs

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Energy

• Four methods of measurement
• Digestible Energy (DE)
• Total Digestible Energy (TDE)
• Metabolizable Energy (ME)
• Net Energy (NE)
• Gross energy of feed is measured in a lab using a
  bomb calorimeter
• The feed is burned completely and the total
  amount of heat released from the burning is the
  gross energy

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Digestible Energy

• The gross energy of the feed minus the energy
  remaining in the feces of the animal after the
  feed is digested

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Metabolizable Energy

• For Ruminants
• The gross energy in the feed minus the energy
  found in the feces, gaseous products of digestion
  and urine
• For Non Ruminants
• The gross energy in the feed minus the energy
  found in the feces and urine

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Net Energy

• Metabolizable energy minus the heat increment
• Energy used for
• Maintenance only NEm
• Amount of energy used to keep the animals energy
  in equilibrium-there is no net gain or loss of
  energy in the animals body tissues
• Maintenance plus production NEmp
• Production only NEp
• Amount of energy need above the amount used for
  maintenance that is used for work, tissue growth,
  fat production, fetus growth, or milk, egg, or
  wool production and so on

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Total Digestible Nutrients (TDN)

• Total of the digestible protein, digestible
  nitrogen-free extract, digestible crude fiber and
  2.25 Xs the digestible fat
• Gives a measure of the total energy value of the
  feed when it is fed
• Varies with the class of animal to which it is
  fed
• Should not be more than about 5 more than what
  the animal needs

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Balancing Calcium and Phosphorus

• Important in balancing rations
• Should be between a 11 and 21 ratio
• The ratio is more important than the total amount
  being fed
• Total Ca and P are often more than needed when
  other requirements are met
• Other mineral needs are usually not considered
  and can be met with trace-mineralized salt

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Vitamins

• Vitamin A is taken into account when balancing
  the ration
• Other vitamin needs are added with out
  calculating the vitamin content of the feed
• Vitamin A will often be more than needed but is
  not harmful
• Vitamin deficiencies can occur in cattle and
  sheep during pregnancy if low quality legume hay
  is fed
• Vitamin supplements should always be added to
  pregnancy rations

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Getting the Most Bang for Your Buck

• Some feeds are cheaper sources of nutrients than
  others
• Energy feeds should be compared based on the
  price per pound of energy (TDN, DE, ME or NE)
• Protein feeds should be compared in terms of
  price per pound of total protein or digestible
  protein
• The least expensive source of nutrients should be
  used as much as possible

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Relationship Between 100 Dry Matter Basis and
As-Fed Basis

• All feed contains some moisture and the amount
  varies with the feed, form of feed, stage of
  growth at harvest, length of time in storage,
  storage conditions
• The appendix in the back of the book shows the
  average percent dry matter in the feeds listed

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100 Dry Matter Basis

• Data presented is calculated on the basis that
  all moisture has been removed

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As-Fed Basis

• Data is calculated on the basis of the average
  amount of moisture found in the feed as it is
  used on the farm

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Rules of Thumb for Balancing Rations
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Beef

• See p. 172-73 in text

44
Swine

• See p. 173 in text

45
Sheep

• See p. 173 in text

46
Goats

• See p. 173 in text

47
Horses

• See p. 173-74 Table 8-2

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Poultry

• See p. 174 in text

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Steps in Balancing a Ration
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Step 1

• Identify the kind, age, weight and function of
  the animal(s) for which the ration is being
  formulated.
• In our text suggested rations and feeding
  programs are found in the units on the specific
  species these may be used for formulating
  rations.

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Step 2

• Consult the table of nutrients to determine the
  nutrient need(s) of the animal(s)
• These requirements are called FEEDING STANDARDS
• Based on average requirements
• May not meet the needs under specific conditions
• Adjustments may be needed if unusual conditions
  exsists

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Step 3

• Choose the feeds to be used
• Consult the feed composition table to determine
  the nutrient content of the selected feed
• Nutrient contents differ with species

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Step 4

• Calculate the amount of each feed to be used in
  the ration
• Sevral methods are available to do this but we
  will use the Pearson Square Method

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Step 5

• Check the ration formulated against the needs of
  the animal(s)
• If there is/are excessive amount(s) of a
  nutrient(s) present it may be necessary to
  reformulate the ration

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Determining Ration Costs

• Check the ration cost to see if it is the most
  economical
• Calculate cost per pound or per ton
• Daily cost of feeding may also be calculated if a
  daily consumption rate is know

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Pearson Square
45
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The Pearson Square

• Cannot balance rations by trial and error
• Pearson Square simplifies balancing rations
• Can only use two feeds

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Using the Pearson Square

• EXAMPLE
• 2,000 pounds of feed is needed to feed a
  100-pound growing hog. A feeding standards table
  shows that a 14 crude protein ration is needed.
  Corn and Soybean oil meal (SBOM) are selected as
  feeds. A feed composition table shows that corn
  has 8.9 and SBOM has 45.8 crude protein on an
  as-fed basis. How much corn and soybean oil meal
  need to be mixed together for 2,000 pounds of
  feed?

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STEP 1

• Draw a square with lines connecting the opposite
  corners.
• Write the percent of crude protein (14) in the
  center of the square.

14
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STEP 2

• Write the feeds to be used and their crude
  protein percents at the left hand corners of the
  square.

Corn 8.9
14
Soybean oil meal 45.8
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STEP 3

• Subtract the smaller number from the larger,
  along the diagonal lines. Write the differences
  at the opposite end of the diagonals.

31.8 45.8-14
Corn 8.9
14
Soybean oil meal 45.8
5.114-8.9
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STEP 3

• The difference between the percent protein in the
  soybean oil meal and the percent protein in the
  ration are the parts of corn needed.
• The difference between the percent protein in the
  corn and the percent protein in the ration are
  the parts of soybean oil meal neeeded.
• The sum of the numbers on the right equals the
  difference in the numbers on the left. This fact
  is used as a check to see if the square is set up
  correctly.

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STEP 3
Parts Corn
31.8
Corn 8.9
14
Soybean oil meal 45.8
Parts SBOM
5.1
36.9
36.9
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STEP 4

• Divide the parts of each feed by the total parts
  to find the percent of each feed in the ration
• Corn 31.8/36.9x10086.2
• Soybean oil meal 5.1/36.9x10013.8

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STEP 5

• It is known that 2,000 pounds of the mixture is
  needed. To find the pounds of each feed in the
  mix, the percent of each feed is multiplied by
  the total pounds of the mix
• Corn 2,000 x 0.862 1,724 pounds
• SBOM 2,000 x 0.138 276 pounds
• Numbers have been rounded to full pounds.

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STEP 6

• Check the mix to ensure that the protein need is
  met. Multiply the pounds of the feed in the its
  precent protein .
• Corn 1,724 x 0.089 153 lbs of Corn
• SBOM 276 x 0.458 126 lbs of SBOM
• Add the pounds of protein together
• 153 126 279
• Divide by the total weight of the mix
• 279/2,000 x 100 14
• The mix is balanced for crude protein content!

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Using the Pearson Square to Mix Two Grains with a
Supplement (START)

• Can be used to find out how much of two grains
  should be mixed with a supplement
• Proportions of grain must be known first

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EXAMPLE

• 2,000 pound mix of corn, oats and soybean oil
  meal is needed. The mix is to contain 16
  Digestible Protein. A decision is made to use ¾
  corn and ¼ oats in the mix. Thus, the proportion
  of corn to oats is 31. How many pounds of corn,
  oats and soybean oil meal are needed?

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STEP 1

• Need to find the weighted average percent of
  protein in the corn and oats first.
• To do this
• Multiply the proportion of corn (3) by the
  percent digestible protein in corn (7.1). Do the
  same for oats. Then add the two answers together
  and divide by the total parts (4). This answer is
  the weighted average percentage of digestible
  protein in the corn oats mix.

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STEP 1 cont

• 3 x 7.121.3 (Corn)
• 1 x 9.9 9.9 (Oats)
• 31.2
• 31.2/4 7.8 Digestible Protein in the corn-oats
  mix

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Using the Pearson Square X

• Used in the same method as before to mix two
  feeds.
• On a sheet of paper, work out this problem

16
3 parts Corn, 1 part oats 7.8
Soybean oil meal 41.7
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Using the Pearson Square

• Same method can be used for mixing two protein
  supplements and 1 grain
• Can also be used to mix 2 grains and 2 protein
  supplements
• Just remember that the proportions of like feed
  must be decided upon before hand and the weighted
  average percent of protein found
• Any measure of nutrients in the feed may be used
• Energy- TDN, NE, ME, DE
• Protein- CP, DP

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Balancing A Swine Ration

• See p. 178-179 in Text

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Balancing a Ration for Beef

• See p. 179-181 in Text

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Using Algebraic Equation to Balance Ration

• May be used instead of Pearson Square
• Basic equations are
• X pounds of grain needed
• Y pounds of supplement
• Equation 1
• XY Total Pounds of Mix Needed
• Equation 2
• ( Nutrient in grain) x (X) ( Nutrient in
  Supplement) x (Y) pounds of nutrient desired in
  mix

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EXAMPLE

• Same problem as the 1st Pearson Square Example
• Mix of 2,000 lbs is to be balanced for protein
  using two feeds.

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EXAMPLE cont

• Place the desired values in equation 2
• REMEMBER TO EXPRESS AS DECIMALS
• 0.089X0.458Y280
• 280 is found by multiplying the quantity of feed
  (2,000 lbs) by the percent (14) or the amount
  of nutrient desired 2,000x0.14)

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EXAMPLE cont

• Either X or Y must be canceled by the
  multiplication of equation 1 by the percentage of
  nutrients for either X or Y, and the resulting
  equation 3 is subtracted from equation 2. This
  example uses the percentage crude protein for
  corn (0.089), giving equation 3
• 0.089X0.089Y178 (178 is found by multiplying
  0.089 times 2,000 lbs)

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EXAMPLE cont

• SUBTRACT equation 3 from equation 2
• 0.089X0.458Y280
• -0.089X-0.089Y -178
• 0.369Y102
• Y 276 lbs soybean meal
• X may then be found by substituting the value of
  Y in equation 1 and solving
• X2762,000
• X2,000-276
• X 1,724 lbs of corn

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Algebraic Equations

• Get the same result as Pearson square
• May be used to balance rations using 3 or more
  feeds
• Same initial step must be taken as when using the
  Pearson Squaregroup similar feeds into two
  groups and determine the proportions of each to
  be used in each group
• After this is done the same procedure as above is
  followed.