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Balancing Rations

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					Balancing Rations
Animal Science II
Unit 8
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
Classification of Feeds
Roughages
   Contain more than 18% crude fiber when dry
   Includes: hay, silage, pasture, fodder
   2 general class: legume roughage and non-
    legume roughage
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
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)
Concentrates
   Less than 18% crude fiber when dry
   Two classes
       Protein supplements
       Energy feeds
Protein Supplements
   20% or more protein
   Divided into 2 groups based on their source
Protein Supplements
   Animal proteins                      Vegetable Proteins
      Come from animals or                 Come from plants
       animal by-products                   Common: soybean oil meal,
      Common: tankage, meat                 cottonseed meal, linseed oil
       scraps, meat and bonemeal,            meal, peanut oil meal, corn
       fish meal, dried milk (whole          gluten feed, brewers dried
       & skimmed), blood meal,               grains, distillers dried grains
       feather meal                         Most contain less than 47%
      Most contain more than 47%            crude protein
       crude protein                        Soybean oil meal is used
      More balanced essential               most
       amino acids                               Can supply necessary
      Variable quality compared                  amino acids for swine
       to vegetable proteins                      and poultry
                                            Only protein source that can
                                             be used for ruminants
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
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
Ration Characteristics
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
Palatability
   Ration must taste good
   Mold, insect and weather damage all lower
    palatability
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
Poisonous Plants
   Should not be included in the diet
   Sometimes grow in hay fields or pastures
   See Table 8-1 p.165
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
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
Functions of the Ration
Functions of Rations
   Must be considered when determining
    nutrient requirements
   Functions include
       Maintenance
       Growth
       Fattening
       Production
       Work
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
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
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
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
Reproduction
   Requires proper nutrition
   Animals may become sterile
   Extremely important for pregnant animals
       Most of the fetus’s growth takes place during the
        last third of the pregnancy
       Additional amounts of nutrients are needed
        during pregnancy
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
Balancing Rations
General Principals
   Must meet the nutritional needs
   Nutrient allowance should be met as close as
    possible
       Not more than 3% below the requirement
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
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
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
Digestible Energy
   The gross energy of the feed minus the energy
    remaining in the feces of the animal after the
    feed is digested
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
Net Energy
   Metabolizable energy minus the heat increment
   Energy used for
       Maintenance only NEm
           Amount of energy used to keep the animal’s energy in
            equilibrium-there is no net gain or loss of energy in the animal’s
            body tissues
       Maintenance plus production NEm+p
       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
Total Digestible Nutrients (TDN)
   Total of the digestible protein, digestible nitrogen-
    free extract, digestible crude fiber and 2.25 X’s 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
Balancing Calcium and Phosphorus
   Important in balancing rations
   Should be between a 1:1 and 2:1 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
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
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
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
100% Dry Matter Basis
   Data presented is calculated on the basis that
    all moisture has been removed
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
Rules of Thumb for Balancing
Rations
Beef
   See p. 172-73 in text
Swine
   See p. 173 in text
Sheep
   See p. 173 in text
Goats
   See p. 173 in text
Horses
   See p. 173-74 & Table 8-2
Poultry
   See p. 174 in text
Steps in Balancing a
Ration
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.
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
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
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
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
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
Pearson Square

                 45
The Pearson Square
   Cannot balance rations by trial and error
   Pearson Square simplifies balancing rations
   Can only use two feeds
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?
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
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
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               5.1=14-8.9
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.
STEP 3

       Corn 8.9        31.8 Parts Corn




                  14
  Soybean
  oil meal 45.8        5.1 Parts SBOM

         36.9          36.9
STEP 4
   Divide the parts of each feed by the total parts
    to find the percent of each feed in the ration
     Corn 31.8/36.9x100=86.2%
     Soybean oil meal 5.1/36.9x100=13.8%
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.
STEP 6
   Check the mix to ensure that the protein need is met.
    Multiply the pounds of the feed in the it’s 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!
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
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 3:1. How many
    pounds of corn, oats and soybean oil meal are
    needed?
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.
STEP 1 cont…
   3 x 7.1=21.3 (Corn)
   1 x 9.9= 9.9 (Oats)
            31.2
   31.2/4= 7.8% Digestible Protein in the corn-
    oats mix
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

       3 parts Corn, 1 part oats 7.8


                                       16

           Soybean oil meal 41.7
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
Balancing A Swine Ration
   See p. 178-179 in Text
Balancing a Ration for Beef
   See p. 179-181 in Text
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
       X+Y= Total Pounds of Mix Needed
   Equation # 2
       (% Nutrient in grain) x (X) + (% Nutrient in Supplement)
        x (Y)= pounds of nutrient desired in mix
EXAMPLE
   Same problem as the 1st Pearson Square
    Example
   Mix of 2,000 lbs is to be balanced for protein
    using two feeds.
EXAMPLE cont…
   Place the desired values in equation 2
       REMEMBER TO EXPRESS % AS DECIMALS


   0.089X+0.458Y=280
       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)
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
       0.089X+0.089Y=178 (178 is found by
        multiplying 0.089 times 2,000 lbs)
EXAMPLE cont…
   SUBTRACT equation 3 from equation 2
        0.089X+0.458Y=280
        -0.089X-0.089Y= -178
                 0.369Y=102
                       Y= 276 lbs soybean meal
   X may then be found by substituting the value of Y
    in equation 1 and solving
       X+276=2,000
       X=2,000-276
       X= 1,724 lbs of corn
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 Square—group 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.

				
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