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Chapter 19 Dairy ration formulation.

TERMINOLOGY

Workbook A workbook is the spreadsheet program file including all its worksheets.

Worksheet A worksheet is the same as a spreadsheet. There may be more than one worksheet in a workbook.

Spreadsheet A spreadsheet is the same as a worksheet.

Cell A cell is a location within a worksheet or spreadsheet.

Comment A comment is a note that appears when the mouse pointer moves over the cell. A red triangle in the upper right corner of a cell indicates that it contains a comment. Comments are added to help explain the function and operations of workbooks.

Input box An input box is a programming technique that prompts the workbook user to type information. After typing the information in the input box, the user clicks OK or strikes ENTER to enter the typed information.

Message box A message box is a programming technique that displays a message. The message box disappears after the user clicks OK or strikes ENTER.

EXCEL SETTINGS

Security: Click on the Tools menu, Options command, Security tab, Macro Security button, Medium setting.

Screen resolution: This application was developed for a screen resolution of 1024 x 768. If the screen resolution on your machine needs to be changed, see Microsoft Excel Help, "Change the screen resolution" for instructions.

HANDS-ON EXERCISES

DAIRY RATION FORMULATION

Double click on the DairyRation icon. The message box in Figure 19-1 displays.
Figure 19-1

Macros may contain viruses. It is advisable to disable macros, but
if the macros are legitimate, you may lose some functionality.
Disable Macros or Enable Macros or More Info


Click on Enable macros. The message box in Figure 19-2 displays.
Figure 19-2

Function keys F1 to F10 are set up. You may return to this location
from anywhere by striking ENTER, then the F1 key. Workbook by David
A. Tisch. The author makes no claim for the accuracy of this
application and the user is solely responsible for risk of use.
You're good to go. TYPE ONLY IN THE GRAY CELLS! Note: This workbook
is made up of charts and a worksheet. The charts and worksheet are
selected by clicking on the tabs at the bottom of the display.
Never save the workbook from a chart; always return to the
worksheet before saving the Workbook.


Click OK.

Input Dairy Animal Procedure

Click on the Input Dairy Animal button. The input box shown in Figure 19-3 displays.
Figure 19-3

1. Lactating

2. Dry cow

3. Replacement heifer.

ENTER THE APPROPRIATE NUMBER:


Click OK to choose the default input of #1, the Lactating dairy animal. The input box shown in Figure 19-4 displays.
Figure 19-4

Enter measured DMI (pounds) if available or click OK to accept the
predicted value at CX26.


Click OK to accept the predicted dry matter intake. The message box shown in Figure 19-5 displays.
Figure 19-5

Enter the appropriate Cell Inputs in column CX; then click the
ENVIRONMENT INPUTS button to continue.


Click OK.

The Cell Inputs

Enter the cell inputs in Table 19-1. Comments associated with the cell inputs follow.

Animal Inputs

The comment behind the cell containing the Condition Score label is shown in Table 19-2.

The comment behind the cell containing the Breed label is shown in Figure 19-6.
Figure 19-6

Breed effects on nutrient requirements are minimal. The breed
selected will determine mature weight and calf birth weight, which
will affect growth requirements.


The information below the input section is shown in Figure 19-7. Note associated comments behind these cells.
Figure 19-7

84   Cow Milk Potential (lb.) based on where the cow is on the herd's
     lactation curve. NOT AN INPUT.
0.0  Target ADG (lb.) to meet growth targets. NOT AN INPUT.


Click on the button at the bottom of the Animal Inputs display to go to the Environment Inputs section and enter the values shown in Table 19-3.

The comment behind the cell containing the Heat Stress label is shown in Figure 19-8.
Figure 19-8

Enter 1 if no heat stress, 2 for rapid/shallow panting, 3 for
open-mouth panting.


Strike ENTER and F1 to return to the home display.

Select Feeds Procedure

Click on the Select Feeds button. The note in Figure 19-9 displays.
Figure 19-9

Nutrient content expressed on a dry matter basis. Feedstuffs are
listed first by selection status, then, within the same selection
status, by decreasing protein content, then, within the same
protein content, alphabetically. Feedstuff DE and NDFdig are
calculated values--strike F10 to calculate these values after
entering new analysis values.


Click OK.

Explore the table. Note the nutrients listed as column headings. Note also that the table ends at row 200. You select feedstuffs for use in making two different products: (1) a blend to be mixed and sold

bagged or bulk, and (2) the ration to be fed directly to livestock.

Select the feedstuffs in Table 19-4 by placing a 1 in the column to the left of the feedstuff name. All unselected feedstuffs should have a 0 value in the column to the left of the feedstuff name. If you wish to group feedstuffs but not select them, you would place a value between 0 and 1 to the left of the feedstuff name.

Strike ENTER and F2.

Selected feedstuffs and their analyses are copied to several locations in the workbook.

Make Ration Procedure

Click on the Make Ration button. The message box shown in Figure 19-10 displays.
Figure 19-10

ENTER POUNDS TO FEED IN COLUMN B. TOGGLE BETWEEN NUTRIENT WEIGHTS
AND CONCENTRATIONS USING THE F5 KEY, RATION AND FEED CONTRIBUTIONS
USING THE F6 KEY, AMINO ACID FLOWS USING THE F7 KEY, AND ENERGY
CALCULATIONS USING THE F9 KEY. WHEN DONE STRIKE F1. Cell is
highlighted in red if nutrient provided is poorly matched with
nutrient target. The lower limit is taken as 94 to 98 percent of
target, depending on the nutrient. The upper limit of acceptable
mineral is taken from National Research Council. 1980. Mineral
Tolerance of Domestic Animals. National Academy Press. This
publication gives safe upper limits of minerals as salts of high
bioavailability, which corresponds to the values calculated here.
Vitamin limits are taken from the NRC, 1987. For other nutrients,
the upper limit is based on unreasonable excess and the expense of
unnecessary supplementation. See Table 19-6 for specifics.


Click OK.

The message box in Figure 19-11 displays.
Figure 19-11

The Goal Seek feature may be useful in finding the pounds of a
specific feedstuff needed to reach a particular nutrient target:

1. Select the red cell highlighting the deficient nutrient

2. From the menu bar, select Tools, then Goal Seek

3. In the text box, "To Value:" enter the target to the right of
the selected cell

4. Click in the text box, "By changing cell:" and then click in the
gray "Pounds fed" area for the feedstuff to supply the nutrient

5. Click OK. You may accept the value found by clicking OK or
reject it by clicking Cancel.

WARNING: Using Goal Seek to solve the unsolvable (e.g., asking it
to make up an iodine shortfall with iron sulfate) may result in
damage to the Workbook.

IMPORTANT: If you return to the Feedtable to remove more than 1 one
feedstuff from the selected list, you will lose your chosen amounts
fed in the developing ration.


Click OK.

In the gray area to the right of the feedstuff name, enter the pound values shown in Table 19-5.

The Nutrients Supplied Display

The application highlights ration nutrient levels, expressed as amount supplied per dairy animal per day, that fall outside the acceptable range.

The lower limit for DMI is 94 percent of the target. With the exception of energy and protein, the lower limit for all ration nutrients is taken as 98 percent of the target. Energy and protein levels are used to predict performance so no limits are set. Table 19-6 shows the upper limits of the acceptable range for the various inputs.

The Nutrients Supplied display shows nutrient amounts supplied in the diet and nutrient targets for the inputted lactating dairy animal. All nutrient levels appear to be within acceptable ranges as established by the application.

The cost of this ration using initial dollar-per-ton values is $3.49 per head per day.

Milk supported by energy (lb.): 87

The comment behind the cell containing the Milk Supported by Energy label is shown in Figure 19-12.
Figure 19-12

Note that the urea cost is a maintenance energy cost and that it
has been added to the maintenance energy required.


The comment behind the cell showing the predicted pounds milk supported by energy is shown in Figure 19-13.
Figure 19-13

This is the milk production (in pounds) that is supported by the
level of energy in the diet.


Milk supported by protein (lb.): 82

The comment behind the cell containing the Milk Supported by Protein label is shown in Figure 19-14.
Figure 19-14

Ration protein and energy content should support similar levels of
performance--otherwise nutrients are wasted. This waste may be
acceptable if it does not adversely affect profitability, the
environment, or animal health.

In early lactation, it may be desirable to formulate the ration so
that dietary protein will support slightly more milk production
than dietary energy, because the animal can use energy reserves in
body fat in addition to feed energy to support milk production. In
later lactation, the animal should receive a ration that allows her
to restore her energy reserves in body fat.


The comment behind the cell showing the predicted pounds milk supported by protein is shown in Figure 19-15.
Figure 19-15

This is the milk production (in pounds) that is supported by the
level of protein in the diet. The level of milk supported by the
protein content should be within 15 percent of that supported by
the energy content.


Milk supported by methionine: 119

The comment behind the cell showing the predicted pounds milk supported by the first limiting amino acid is shown in Figure 19-16.
Figure 19-16

This is the milk production (in pounds) that is supported by the
level of the first limiting amino acid in the diet (see notes at
F7).


Max milk supported: 82

The comment behind the cell containing this label is shown in Figure 19-17.
Figure 19-17

If the max milk supported is significantly greater than the cow
milk potential, cows may not be able to realize the milk production
supported by this ration. Excess nutrients will be excreted.


Cow milk potential: 84

The comment behind the cell containing this label is shown in Figure 19-18.
Figure 19-18

This is the predicted amount of milk that this cow is capable of
making based on the inputs.


IOF (Income Over Feed) cost using max milk: $6.40

The comment behind the cell containing this label is shown in Figure 19-19.
Figure 19-19

IOF (Iincome Over Feed) cost is calculated here as follows:

[(inputted milk price/100) x max milk supported]--ration cost Note
that the IOF cost using max milk increases with increasing max milk
supported. However, if the max milk supported is greater than the
cow milk potential, the excess nutrients will go into storage or be
excreted.


IOF (Income Over Feed) cost using cow milk potential: $6.56

The comment behind the cell containing this label is shown in Figure 19-20.
Figure 19-20

IOF cost is calculated here as follows:

(inputted milk price/100 x cow milk potential)--ration cost Because
cow milk potential is a fixed value based on animal and environment
inputs, IOF cost using cow milk potential decreases with increasing
ration cost.

                  Pounds  Percent

RDP                6.13     64.02


The comment behind the cell containing this label is shown in Figure 19-21.
Figure 19-21

RDP is rumen degradable protein. It is the portion of feed protein that
rumen microbes can use for food. In most diets, RDP should be greater
than RUP because RDP is cheaper and usually the microbes grown on
RDP deliver a better-quality protein to the mammary gland.


The comment behind the cell containing the percent RDP value is shown in Figure 19-22.
Figure 19-22

Percentage of crude protein.

              Pounds   Percent
RUP            3.45     35.98


The comment behind the cell containing this label is shown in Figure 19-23.
Figure 19-23

RUP is rumen undegradable protein. This is the portion of feed
protein that bypasses the rumen microbes and goes directly to the
small intestine. If digestible and metabolizable, it then is
delivered to the tissues and mammary gland.


The comment behind the cell containing the percent RUP value is shown in Figure 19-24
Figure 19-24

Percentage of crude protein.

                  Pounds   Percent

MP-bacteria        2.87    48.15


The comment behind the cell containing this label is shown in Figure 19-25.
Figure 19-25

MP-Bacteria is the metabolizable protein from the bacterial cells
grown in the rumen on the feed's RDP (rumen degradable protein). 45
to 80 percent of the nitrogen reaching the small intestine is of
microbial origin.


The comment behind the cell containing the percent MP-bacteria value is shown in Figure 19-26.
Figure 19-26

MP-bacteria percentage: percentage of total metabolizable protein.

                    Pounds  Percent
MP-RUP               2.83    47.59


The comment behind the cell containing this label is shown in Figure 19-27.
Figure 19-27

MP-RUP is the portion of the feed protein that is not degraded in
the rumen (rumen undegradable protein), yet is digestible and
metabolizable. It is also known as bypass protein. Though most
nutritionists recommend that most of the total MP come from
MP-bacteria, higher producers will generally have to have a greater
proportion of their total MP coming from RUP.


The comment behind the cell containing the percent MP-RUP value is shown in Figure 19-28.
Figure 19-28

MP-RUP percentage: percentage of total metabolizable protein. In
most rations, this should not be as great as the MP produced in the
rumen by bacteria.

                       Pounds  Percent
MP-Endogenous           0.25    4.27


The comment behind the cell containing this label is shown in Figure 19-29.
Figure 19-29

MP-endogenous includes metabolizable protein coming from sloughed
epithelial cells in the digestive and respiratory systems as well
as enzyme secretions into the abomasum.


The comment behind the cell containing the percent MP-endogenous value is shown in Figure 19-30.
Figure 19-30

MP-endogenous percentage: percentage of total metabolizable
protein.

                      Pounds   Percent
MP total               5.95    11.06


The comment behind the cell containing this label is shown in Figure 19-31.
Figure 19-31

MP is Metabolizable Protein, and the total level provided is the
sum of MP from bacteria, MP from RUP and MP from endogenous
sources. Maximizing MP total is an important goal in feeding
ruminants and requires an understanding of the impact of different
feeding management strategies on the supply of MP-Bacteria and
MP-RUP.


The comment behind the cell containing the percent MP total value is shown in Figure 19-32.
Figure 19-32

MP total percentage: percentage of DMI.

                     Pounds   Percent

CP total              9.58    17.79


The comment behind the cell containing this label is shown in Figure 19-33.
Figure 19-33

Crude protein is measured as 6.25 x (the feed nitrogen content).
Because other feed components besides protein contain nitrogen, it
is described as crude protein.


The comment behind the cell containing the percent CP total value is shown in Figure 19-34.
Figure 19-34

CP total percentage: percentage of DMI.

                    Mcal
UREA cost           0.00


The comment behind the cell containing this label is shown in Figure 19-35.
Figure 19-35

The urea cost is the cost in Mcal of ME to dispose of the nitrogen
in the ration's unused protein. This amount of energy becomes part
of the maintenance requirement at the expense of other functions.
Approximately 0.52 Mcal of ME is used to make 1 lb. of milk
containing 3.5 percent fat. Therefore, if energy is limiting
production, each multiple of 0.52 ME used in protein excretion
results in a pound of lost milk. The value here has been included
in the calculation of the maintenance energy (ME) requirement.


% Forage: 60.7%

The comment behind the cell containing this label is shown in Figure 19-36.
Figure 19-36

This is the percentage of forage in the feed dry matter. It is one
of the oldest ways of assessing effective fiber in the diet. The
usual recommendation is that the ration should contain more than 40
percent forage.


Predicted rumen pH: 6.46

The comment behind the cell containing this label is shown in Figure 19-37.
Figure 19-37

Dry matter intake (DMI) begins to fluctuate at a ruminal pH below
6.2. At a ruminal pH below 6.0, the ability of bacteria to derive
energy from forages declines.

Note that although it is advisable to feed buffer to help manage
ruminal pH on high-grain diets, buffer is not considered here in
the ruminal pH prediction.


The Nutrient Concentration Display (strike F5)

The nutrients in the ration and the predicted nutrient targets are expressed in terms of concentration. That is, the nutrients provided by the ration are divided by the amount of ration dry matter and the nutrient targets are divided by the target amount of ration dry matter. Concentration units include percentage, milligrams per kilogram or parts per million, calories per pound, and international units per pound.

DCAD: 137

The comment behind the cell containing this label is shown in Figure 19-38.
Figure 19-38

Dietary Cation--Anion Difference (DCAD). DCAD is used to assess the
impact of the ration's mineral content on the body's efforts to regulate
blood pH. It can also be manipulated to prevent milk fever. Feeding
anionic salts to dry cows for the 2 weeks prior to freshening reduces
the DCAD, forcing cows to mobilize calcium. This prepares cows for early
lactation in which they also must mobilize calcium. Because anionic
salts are generally unpalatable, there is a risk that feed intake will
be negatively impacted and, therefore, manipulation of DCAD should
probably only be considered where milk fever is a significant problem.
The equation used here is:

        (mEq (Ca_Mg_Na_K) - mEq (Cl + S+P))/kg DMI
                                               (Goff, J. 2000.)

To prevent milk fever, a goal would be to achieve a -40 to 50 DCAD.
The Goff reference is a personal communication reported in D. G. Fox,
T. P. Tylutki, M. E. Van Amburgh, L. E. Chase, A. N. Pell, T. R.
Overton, L. O. Tedeschi, C. N. Rasmussen, & V. M. Durbal. 2000. The
Net Carbohydrate and Protein System for Evaluating Herd Nutrition and
Nutrient Excretion, CNCPS version 4.0. Animal Science Department
Mimeo 213. Cornell University.


Ca:P(abs) 1.25

The comment behind the cell containing this label is shown in Figure 19-39.
Figure 19-39

Calcium-to-phosphorus ratio. This ratio is of little significance
if requirements for phosphorus and calcium are met. No differences
in milk yield, persistency of milk production, milk composition, or
reproductive performance were found in cows during early lactation
fed diets with calcium to phosphorus ratios ranging from 1:1 to
8:1.

        Dairy NRC, 2001.


N:S(abs) 14.2

The comment behind the cell containing this label is shown in Figure 19-40.
Figure 19-40

The dietary nitrogen-to-sulfur ratio should be between 10:1 and
12:1 for efficient utilization of nonprotein nitrogen (urea).
(Bouchard, R. and H. R. Conrad. 1973. J. Dairy Sci. 56, 1276-1282;
Qi et al., 1993. J. Anim. Sci.). This is because the rumen microbes
need a source of sulfur with nitrogen to synthesize the sulfur
containing amino acids. This recommendation is based on total
sulfur, not bioavailable sulfur. However, since most sulfur sources
are 100 percent bioavailable, little error is incurred when using
bioavailable sulfur. Nitrogen was calculated from crude protein
using 16 percent as the average nitrogen content of protein. This
ratio may be ignored if urea is not being fed.


LCT ([degrees]F) -39.46

The comment behind the cell containing this label is shown in Figure 19-41.
Figure 19-41

LCT (lower critical temperature) is calculated from body insulation
and heat production. Since heat production is dependent upon the
energy content of the ration, the LCT will change with the energy
content of the ration. Animals in environments below the LCT are
cold stressed and will use feed energy to maintain their body
temperature, leaving fewer nutrients available for other functions.


Daily weight change, lb. (cows) 0.44

The comment behind the cell containing this label is shown in Figure 19-42.
Figure 19-42

This calculation is based on how the ration's energy status is
affecting daily body weight change. If there is excess energy, the
animal will be replenishing reserves and gaining weight; if there
is an energy shortage, the animal will be mobilizing body fat and
losing weight.

For dry cows, this value should be within 20 percent of the target
average daily gain (ADG).

For close-up dry cows, which will be on the ration for only a short
time, it may be acceptable to have a high predicted rate of gain
because the goal is to prepare the rumen for the high-grain ration
of a lactating group.


Days to gain 1 CS 471

The comment behind the cell containing this label is shown in Figure 19-43.
Figure 19-43

Based on whether dietary energy is deficient or in excess of
requirement, the animal may be gaining or losing body weight. The
value shown is the number of days to lose or gain enough body-fat
reserves to change a BCS (5 point scale). To calculate what one BCS
equates to in terms of pounds, multiply the days to gain/lose 1 BCS
by the daily weight change.

A cow's energy deficit should not be so deep that she is predicted
to lose a BCS in less than 100 days.

For close-up dry cows, see the comment under Daily weight change.


Strike F5.

The Feedstuffs Contributions Display (strike F6)

Shown here are the nutrients contributed by each feedstuff in the ration. This display is useful in troubleshooting problems with nutrient excesses.

Strike F6.

The Amino Acid Flows and Production Potentials Display (strike F7)

Shown here are the essential amino acids, their predicted flows to the small intestine, the percent of MP this represents, and the pounds of milk this could support. These calculations do not consider how shifting metabolic pathways affect amino acid supply and demand.

Strike F1.

The Graphic Display

At the bottom of the home display are tabs. The current tab selected is the Worksheet tab. Other tabs are graphs based on the current ration. Note that you may have to click the leftmost navigation button at the lower-left corner to find the first tab.

DMI

Click on this tab to display a graph titled Nutrient Status: Dry Matter Intake

Energy

Click on this tab to display a graph titled Nutrient Status: Energy

MP

Click on this tab to display a graph titled Sources of Metabolizable Protein (MP)

Macro

Click on this tab to display a graph titled Nutrient Status: Macrominerals

Micro

Click on this tab to display a graph titled Nutrient Status: Microminerals

Vitamins

Click on this tab to display a graph titled Nutrient Status: Vitamins A, D & E

Milk

Click on this tab to display a graph titled Nutrient Support for Milk Production

Click on the Worksheet tab.

Blend Feedstuffs Procedure

Click on the Blend Feedstuffs button. The note in Figure 19-44 displays.
Figure 19-44

YOU MUST HAVE ALREADY SELECTED THE FEEDSTUFFS YOU WANT TO BLEND.
When your analysis is acceptable, strike ENTER and F3 to name and
file the blend. NOTE: The formulas in this Workbook use measured
protein digestion rates, %/hr (Kd), mineral bioavailability and
fat, CP, RUP, NFC, & NDF digestibilities for individual feedstuffs.
When a blend is made and used in a ration, the blend is
"decomposed" and the characteristics of the blend's component
feedstuffs are used. For this reason, DO NOT use one blend as a
component of another blend.


Click OK.

We will plan on having one mineral/vitamin blend.

To the left of the feedstuff name, enter an amount of 0 for all ingredients except the mineral and vitamin sources as shown in Table 19-7.

Notice that as the amounts entered change in the gray area, a calculation is made of the appropriate pounds per ton in the blue area. Because feed mill mixers have capacities rated in tons, it is necessary that formulas to be mixed be expressed in pounds per ton.

Strike ENTER and F3. The input box in Figure 19-45 displays.
Figure 19-45

The name of this blend is BLEND1. This name is accessed in the
application to assign nutrient value; therefore, the name must not
be altered.


Click OK. The message box in Figure 19-46 displays.
Figure 19-46

The new blend has been filed at the bottom of the feed table. When
used in a ration, the blend will be "decomposed" and the digestion
characteristics of its component feedstuffs will be used in
calculations.


Click OK.

View Blends Procedure

Click on the View Blends button to confirm that the BLEND1 formula and analysis have been filed. The note in Figure 19-47 displays.
Figure 19-47

Cursor down for more nutrients. DO NOT TYPE IN THE BLUE AREAS.


Click OK.

After viewing BLEND1, strike F1 to return to the home display.

Using the Blended Feed in the Balanced Ration

Select Feeds Procedure

Click on the Select Feeds button and select the feeds shown in Table 19-8. Unselect all other feedstuffs. Remember that the BLEND1 blend is located at the bottom of the feed table (row 200).

Strike ENTER and F2.

Make Ration Procedure

Click on the Make Ration button. Enter the ration shown in Table 19-9.

The amount of blood meal, soybean meal 49%, soybeans roasted, mixed grass/legume silage mid maturity, mixed grass/legume hay mid-maturity, corn grain ground, and corn silage have already been established. The amount of the BLEND1 to feed is the total amount of its component ingredients in the balanced ration. That value is:

0.25 + 0.000015 + 0.00062 + 0.03681 + 0.0000314 + 0.28 + 0.000023 + 0.02392 + 0.00848 + 0.02238 + 0.002 = 0.62 lb.

This value is recorded at View Blends under Formula, as entered. The ration is balanced as it was when the components of BLEND1 were fed unmixed.

Strike ENTER and F1.

Print Ration or Blend Procedure

Make sure your name is entered at cell C1.

Click on the Print Ration or Blend button. The input box in Figure 19-48 displays.
Figure 19-48

Are you printing a dairy ration evaluation or a blend formula and
analysis? (1-RATION, 2 BLEND)


Click OK to accept the default input of 1. A two-page ration printout will be produced by the machine's default printer.

Click on the Print Ration or Blend button. This time enter a value of 2 to print a blend. Click OK. The message box shown in Figure 19-49 displays.
Figure 19-49

Click on the green number above the blend you want to print and
press F4.


Click OK.

Find the blend named BLEND1. Click on the green number above it and strike F4. A one-page printout of the blend formula and analysis will be produced by the machine's default printer.

ACTIVITIES AND WHAT-IFS

In the Forms folder on the companion CD to this text is a DairyInput.doc file that may be used to collect the necessary inputs for use of the Dairy Ration.xls file. This form may be printed out and used during on-farm visits to assist in ration evaluation activities.

1. Remake the ration described in Table 19-5 for the lactating cow described in this chapter. Blend all feedstuffs. If there is not extensive sorting of the feed fed to the lactating cows, this blend represents the nutrient value of the refusals. Input a dry cow at 250 days pregnant. From the feed table, select the blend that represents the refusals. Meet the dry cow's DMI with the refusals blend. How many days are needed to gain a condition score for this dry cow? What problems might you expect due to this situation? What is the urea cost in this ration? Explain why this value indicates an excess of dietary protein.

2. Remake the ration described in Table 19-9 for the lactating cow described in this chapter. The answers to the following questions are found by striking F9. Given that metabolizable energy is used with similar efficiencies for the functions of maintenance and milk production, feed energy content is expressed as net energy for lactation (NEl) whether discussing maintenance or lactation energy needs. How many megacalories of NE1 are required to meet the maintenance needs of this cow? How many pounds of feed dry matter are needed to deliver this number of mega-calories? How many additional pounds of feed dry matter is this animal eating beyond that needed to supply maintenance energy? How many megacalories of NEl will these additional pounds provide? Given the megacalories of NE1 in one pound of milk as shown at F9, how many pounds of milk is the energy beyond maintenance in this ration capable of supporting? Based on the animal and environmental inputs, what is this cow's milk production potential? What is the difference between the pounds of milk that the energy content of the ration can support and the cow's milk production potential? How many megacalories of NE1 does this difference represent? Given the megacalories NEl per pound reserve change shown at F9, how many pounds of reserves will the cow replenish with the extra megacalories of NE1?

3. Remake the ration described in Table 19-9 for the lactating cow described in this chapter. What amount of milk is supported by the energy and protein levels of the ration? Strike F1 and click on Select Feeds. What is the digestible energy, Mcal/lb. of the corn silage? Change the NDF content for the corn silage from 45 to 35 percent. Strike ENTER and F10 to recalculate digestible energy and digestible NDF. What is the new digestible energy, Mcal/lb. for corn silage? Strike F2 to select this new corn silage. What are the new levels of milk supported by the ration? Back at the feed table, return the corn silage NDF to 45 percent. Strike ENTER and F10. In the mixed grass/legume silage, record the DE, Mcal/lb. and the digestibility of the NDF (NDFdig) lb./lb. Change the lignin percentage in the mixed grass/legume silage from 5.9 to 4 percent. Strike F10. What is the new NDFdig, lb./lb.? What is the new DE, Mcal/lb.? Strike F2 to select the new hay crop silage. What is the effect of this changed analysis on pounds of milk supported by the ration? Explain how changes in forage NDF and lignin affect digestible energy content and NDF digestibility.

REFERENCES

Bouchard, R. & Conrad, H. R. (1973). Sulfur requirement of lactating dairy cows. I. Sulfur balance and dietary supplementation. Journal of Dairy Science. 56, 1276-1282.

Fox, D. G., Tylutki. T. P., Van Amburgh, M. E., Chase, L. E., Pell, A. N., Overton, T. R., Tedeschi, L. O., Rasmussen, C. N., & Durbal, V. M. (2000). The Net Carbohydrate and Protein System for Evaluating Herd Nutrition and Nutrient Excretion, CNCPS version 4.0. Animal Science Department Mimeo 213. Cornell University.

National Research Council. 1980. Mineral Tolerance of Domestic Animals. Washington DC: National Academy Press.

National Research Council. 1987. Vitamin Tolerance of Animals. Washington DC: National Academy Press.

Qi, K., Lu, C. D., & Owens, F. N. (1993). Sulfate supplementation of growing goats: effects on performance, acid-base balance, and nutrient digestibilities. Journal of Animal Science. 71, 1579-1587.
Table 19-1
Animal inputs for the dairy
ration formulation example

    65   Age (months). If a lactating animal
           was chosen, this entry must be >21
           months.
  1400   Body weight (lb.)
   no    Ionophore inclusion (yes/no)
    70   Days pregnant. For dry cows, this
           value should be 220-282. For heifers
           < 55% mature weight, this value
           should be 0
     3   Condition Score (1-5)
   150   Days in milk (DIM). DIM should be
           greater than the number of days
           pregnant by the number of days
           past calving that you wait
           to rebreed.
    24   Age at first calving (months)
    12   Calving interval (months)
     4   Breed (1--Ayrshire, 2--Brown Swiss,
         3--Guernsey, 4--Holstein,
         Jersey, 6--Milking Shorthorn)
   3.5   Milk fat (%)
   3.3   Milk protein (% true protein)
   4.8   Milk lactose (%)
    12   Milk price, dollars per cwt (100 lb.)
24,000   Rolling herd average (used with
           lactation # to create a
           lactation curve for the herd)
     3   Lactation # (used with rolling
           herd average to create a
           lactation curve for
           the herd)

Table 19-2
Body condition score descriptions for dairy cattle

BCS            1                      2

Tailhead       Deep cavity            Shallow cavity

Pelvic bones   Sharp and easily       Prominent and easily
                 felt                   felt

Processes of   Distinct, giving a     Ends rounded, upper
lumbar           sawtooth               surfaces felt with
vertebrae        appearance             slight pressure

Area between   Deep depression        Depression still
processes of                            obvious
lumbar
vertebrae

BCS            3                      4

Tailhead       No cavity              Folds of fat

Pelvic bones   Smooth but felt        Rounded but felt
                 with pressure          with firm
                                        pressure

Processes of   Fat covering upper     Cannot be felt
lumbar           surfaces but still
vertebrae        felt with pressure

Area between   Slight depression      Nearly flat across
processes of                            back
lumbar
vertebrae

BCS            5

Tailhead       Buried in fat

Pelvic bones   Cannot be felt

Processes of   Rounded and
lumbar           covered
vertebrae        with fat

Area between   Rounded
processes of
lumbar
vertebrae

Table 19-3
Environmental inputs for the
dairy ration formulation
example

 60   Current temperature ([degrees]F)

 60   Temperature average for the
        previous month ([degrees]F)

  1   Wind speed (mph)

no    Grazing (yes/no)
      N/A
      N/A
      N/A

0.3   Hair depth, inches (in.)

  2   Coat condition (1--clean/dry, 2--some
        shud on legs, 3--shud on lower body,
        4--covered with shud)

  1   Heat stress unlikely--input
        should probably be 1 (see comment)

Yes   Is there significant relief from
        the heat at night? (Heat stress
        unlikely--input should
        probably be yes.)

Table 19-4

Feedstuffs to select for the
dairy ration formulation
example

Blood meal, flash dried
Soybean meal, 49%
Soybeans, roasted
Mixed grass/legume silage, mid maturity
Mixed grass/legume hay, mid maturity
Corn grain, ground
Corn silage, normal
Calcium carbonate
Cobalt carbonate
Copper sulfate
Dicalcium phosphate
EDDI (Ethylenediamine dihydroiodide)
Salt (sodium chloride)
Sodium selenite
Vitamin A supplement
Vitamin D supplement
Vitamin E supplement
Zinc oxide

Table 19-5
Inclusion rates for feedstuffs
in the dairy ration
formulation example

Blood meal, flash dried                        0.2
Soybean meal, 49%                              5.5
Soybeans, roasted                              1.5
Mixed grass/legume silage, mid maturity       38
Mixed grass/legume hay, mid maturity           3
Corn grain, ground                            16
Corn silage, normal                           38
Calcium carbonate                              0.25
Cobalt carbonate                               0.000015
Copper sulfate                                 0.00062
Dicalcium phosphate                            0.03681
EDDI (Ethylenediamine dihydroiodide)           0.0000314
Salt (sodium chloride)                         0.28
Sodium selenite                                0.0000237
Vitamin A supplement                           0.02392
Vitamin D supplement                           0.00848
Vitamin E supplement                           0.02238
Zinc oxide                                     0.002

Table 19-6
Upper limits for ration nutrients used
in the dairy ration application.

                            Upper Limit

DMI                         6% over predicted requirement

Energy                      No upper limit. Excess beyond
                              maintenance is used
                              to predict performance.
Metabolizable protein       No upper limit. Excess beyond
                              maintenance is used
                              to predict performance.
Calcium--bioavailable       2% of diet dry matter
Phosphorus--bioavailable    1%
Magnesium--bioavailable     0.5%
Potassium--bioavailable     3%
Sulfur--bioavailable        0.4%
Sodium--bioavailable        1.6% lactating, 3.5%
                              nonlactating
Chloride--bioavailable      2.5 lactating, 5.5%
                              nonlactating
Iron--bioavailable          1000 mg/kg or ppm
Manganese--bioavailable     1000 mg/kg or ppm
Copper--bioavailable        100 mg/kg or ppm
Zinc--bioavailable          500 mg/kg or ppm
Iodine--bioavailable        50 mg/kg or ppm
Cobalt--bioavailable        10 mg/kg or ppm
Selenium--bioavailable      2 mg/kg or ppm
Vitamin A                   30 times the requirement
Vitamin D                   4 times the requirement
Vitamin E                   20 times the requirement

                            Source

DMI                         Author

Energy

Metabolizable protein

Calcium--bioavailable       NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle

Phosphorus--bioavailable    NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle

Magnesium--bioavailable     NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle

Potassium--bioavailable     NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle

Sulfur--bioavailable        NRC:Mineral Tolerance of Domestic
                              Animals (1980)

Sodium--bioavailable        NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle, based on
                              limit for salt (sodium
                              chloride)
Chloride--bioavailable      NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle, based on
                              limit for salt (sodium chloride)
Iron--bioavailable          NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle
Manganese--bioavailable     NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle
Copper--bioavailable        NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle
Zinc--bioavailable          NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle
Iodine--bioavailable        NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle
Cobalt--bioavailable        NRC:Mineral Tolerance of Domestic
                              Animals (1980)--cattle
Selenium--bioavailable      NRC:Mineral Tolerance of Domestic
                              Animals (1980)
Vitamin A                   NRC:Vitamin Tolerance of
                              Animals (1987)
Vitamin D                   NRC:Vitamin Tolerance of
                              Animals (1987)
Vitamin E                   NRC:Vitamin Tolerance of
                              Animals (1987)

Table 19-7
Inclusion rates for feedstuffs
in the dairy MinVit blend

Blood meal, flash dried                         0
Soybean meal, 49%                               0
Soybeans, roasted                               0
Mixed grass/legume silage mid maturity          0
Mixed grass/legume hay mid maturity             0
Corn grain, ground                              0
Corn silage, normal                             0
Calcium carbonate                               0.25
Cobalt carbonate                                0.000015
Copper sulfate                                  0.00062
Dicalcium phosphate                             0.03681
EDDI (Ethylenediamine dihydroiodide)            0.0000314
Salt (sodium chloride)                          0.28
Sodium selenite                                 0.0000237
Vitamin A supplement                            0.02392
Vitamin D supplement                            0.00848
Vitamin E supplement                            0.02238
Zinc oxide                                      0.002

Table 19-8

Feedstuffs and blend to select
for the dairy ration
formulation example

Blood meal, flash dried
Soybean meal, 49%
Soybeans, roasted
Mixed grass/legume silage, mid maturity
Mixed grass/legume hay, mid maturity
Corn grain, ground
Corn silage normal
BLEND1

Table 19-9

Feeding rates for feedstuffs
and blend in the dairy ration
formulation example

Blood meal, flash dried                        0.2
Soybean meal, 49%                              5.5
Soybeans, roasted                              1.5
Mixed grass/legume silage, mid maturity       38
Mixed grass/legume hay, mid maturity           3
Corn grain, ground                            16
Corn silage, normal                           38
BLEND1                                         0.62
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Article Details
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Author:Tish, David A.
Publication:Animal Feeds, Feeding and Nutrition, and Ration Evaluation
Geographic Code:1USA
Date:Jan 1, 2006
Words:6269
Previous Article:Chapter 18 Feeding dairy.
Next Article:Chapter 20 Feeding sheep.
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