|
Items in cart [0] |
Questions? Call 888-624-8373 |
| ||||||||||||
| Copyright © 2009. National Academy of Sciences. All rights reserved. Terms of Use and Privacy Statement |
Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 153
-->
Appendix 4
A User's Guide For Model Application
Nutrtient Requirements of Swine
Tenth Revised Edition, 1998
Subcommittee on Swine Nutrition
Committee on Animal Nutrition
Board on Agriculture
National Research Council
OCR for page 154
-->
Subcommittee On Swine Nutrition
GARY L. CROMWELL, Chair, University of Kentucky
DAVID H. BAKER, University of Illinois
RICHARD C. EWAN, Iowa State University
E. T. KORNEGAY, Virginia Polytechnic Institute and State University
AUSTIN J. LEWIS, University of Nebraska
JAMES E. PETTIGREW, Pettigrew Consulting International, Louisiana, Missouri
NORMAN C. STEELE, U.S. Department of Agriculture, Agricultural Research Service, Beltsville, Maryland
PHILIP A. THACKER, University of Saskatchewan, Canada
Staff
CHARLOTTE KIRK BAER, Program Director
MELINDA SIMONS, Project Assistant
Software Interface Development
RONALD HAUGEN, Easy Systems, Inc., Welcome, Minnesota
OCR for page 155
-->
Table of Contents
Chapter 1. Introduction
156
Tutorials
156
Computer Model Programs
156
Feed Composition Tables
157
Hardware and Software Requirements and Program Installation
157
Getting Started
158
Chapter 2. Using the NRC Model Programs
159
About the Screen
160
Task Field
160
Report Field
161
Folder Field
161
Chapter 3. Tutorial Lesson 1
163
General Description of the Growth Model
163
Grow-Finish Case Study
164
Chapter 4. Tutorial Lesson 2
166
General Description of the Gestation Model
166
Gestating Sow Case Study
166
Chapter 5. Tutorial Lesson 3
167
General Description of the Lactation Model
167
Lactating Sow Case Study
167
OCR for page 156
-->
1 Introduction
A compact disk (CD-ROM) containing three models is provided as a companion to the National Research Council's (NRC's) Nutrient Requirements of Swine, Tenth Revised Edition, 1998. This User's Guide provides information with specific examples demonstrating the use of each of the three programs contained on the NRC computer disk. Three model program options for predicting nutrient requirements include programs that address (1) the growing pig, including the starting, growing, and finishing stages of growth from 3 to 120 kg body weight, (2) gestating sows, and (3) lactating sows.
These models allow the user to apply the modeling principles, interrelationships, and equations summarized in Chapter 3 of the report. A basic understanding of swine nutrition is required to properly use the programs, and knowledge of the underlying biological concepts presented in this report is essential for appropriate use of the computer models.
The computer model programs predict energy and amino acid requirements on a daily basis and on a diet concentration basis by estimating the amount of energy and amino acids needed for specific physiologic functions, such as maintenance, body protein accretion, and milk protein synthesis. Equations are given to predict mineral and vitamin requirements at various stages of growth. Numerous factors including body weight, lean growth potential, gender, environmental temperature, space per pig, number of pigs per litter born and weaned, weaning age, litter growth rate, and other factors enter into the equations for predicting nutrient requirements. Each program uses different prediction equations and the inputs required for each program vary according to the various physiologic and metabolic functions being described (i.e., growth, gestation, lactation).
The software was developed for accuracy and ease of use. The programs were developed in database format as the foundation for a Windows-based, menu-driven program. Program "help" screens provide guidelines for choosing inputs and in interpreting and applying outputs.
Tutorials
The purpose of this user's guide is to demonstrate how to apply the NRC computer model programs to predict nutrient requirements of swine. Tutorials familiarize the user with program mechanics and options. In addition, they provide a quick overview of the program applications for each of the three models. Examples are provided that allow the user to input data, obtain predicted nutrient requirements, and evaluate the results. The user is strongly urged to read the comprehensive material provided in this report and is referred to the following chapters for detailed information on biological bases for equations and assumptions used in the software:
Energy, Chapter 1
Proteins and Amino Acids, Chapter 2
Models for Estimating Energy and Amino Acid Requirements, Chapter 3
Minerals, Chapter 4
Vitamins, Chapter 5
Diet Formulation, Chapter 9
Nutrient Requirement Tables, Chapter 10
Composition of Feed Ingredients, Chapter 11
Computer Model Programs
Growth
This model allows the user to compute the daily lysine requirement on a true ileal digestible basis for maintenance and whole body protein accretion. The program uses a lean tissue accretion curve, based on carcass fat-free lean tissue, to predict the lean tissue accretion rate at a given body weight. The carcass lean tissue accretion is then converted to whole body protein accretion by assuming there are 2.55 grams of carcass fat-free lean tissue per gram of whole body protein. The amount of true ileal digestible
OCR for page 157
-->
lysine needed to support that amount of whole body protein accretion is then calculated, based on the assumption that 0.12 gram of lysine is needed for every gram of whole body protein. This amount of lysine needed for protein synthesis plus the amount needed for maintenance are summed. The requirements for the other amino acids are based on the ideal protein system; that is, their ratio to lysine for maintenance and protein accretion. Equations are used to estimate digestible energy intake based on body weight, gender, environmental temperature, and space per pig. Feed intake is then determined from the estimate of digestible energy intake. Mineral and vitamin requirements are estimated for different body weights by equations.
Gestation
This model predicts the amount of dietary energy and amino acids needed by sows of different breeding weights to attain a targeted weight gain during pregnancy. The formula for prediction assumes that total tissue accretion is the sum of that in the maternal body plus the products of conception. The model predicts energy requirement for a given gestation weight gain, or predicts weight gain resulting from a given energy intake. Adjustments in energy intake are made for cold environments.
Lactation
This model predicts the amount of dietary energy and amino acids needed by sows based on their postfarrowing weight, the weight loss or gain during lactation, and the weight gain of the litter, a reflection of the sow's level of milk production. Amino acid requirements are based on the amino acid patterns in tissue protein gain or loss, milk protein, and maintenance. The model predicts energy requirements based on the sow's lactational weight change, or predicts lactation weight change resulting from a given energy intake.
Feed Composition Tables
These tables are provided to allow the user to view and print the composition of 79 different feed ingredients that are commonly used in swine feeding. The tables are also presented in Chapter 11.
Adobe Acrobat Reader is required to view and print the tables. Instructions for installing Adobe Acrobat Reader are provided in the section "Getting Started" in this chapter (Chapter 1) of the User's Guide.
After Adobe Acrobat Reader has been installed, the tables can be viewed by pressing "Tables" at the top of the screen (or if you are already in one of the model programs, by pressing "Feed Tables" at the bottom of the screen). The first screen to appear provides titles of each of the 11 tables. To access a particular table, click on its title and the table containing feed composition data will appear. To move around within individual tables, use the cursor (designated on the screen as a small hand, which points to certain locations as the mouse is moved to different areas on the table).
Various tool tips located on the tool bar at the top of the screen allow the user to move from page to page, to display entire tables on the screen, and to conduct other procedures. For instance, to zoom in on a certain area of the table, select the tool designated as a magnifying glass with a "+" in its center. Move the magnifying glass to the desired section of the screen and click. The portion of the screen being viewed will become magnified. By continuing to click, the image will continue to be enlarged. Portions of the table can also be magnified by selecting with the mouse while holding the mouse button down and outlining the area desired. When the mouse button is released, the area becomes enlarged. To return to the full view, click on the button that shows a full page on the tool bar.
Three buttons located on the left side of the tool bar provide the following useful options: the first button displays only the page, the second button from the left provides a list of tables in the margin of the screen, and the third button from the left provides a full-page view of several tables in the margin.
To exit the tables and return to the main menu, select "File" at the top of the screen and then "Exit." An alternate way to exit is to hold down the ''Alternate" key on the keyboard and press F4.
Risk of use:
Because of the many variables involved and judgments that must be made in choosing inputs and interpreting outputs, the NRC makes no claim for the accuracy of this software and the user is solely responsible for risk of use.
Hardware And Software Requirements And Program Installation
This software is designed to operate in a Windows environment on microcomputers that run Windows 3.1 or higher versions (Windows 95 or NT). The NRC model requires the following hardware:
an IBM compatible computer with 80386sx processor (or higher) with mouse;
8 Megabytes random access memory (RAM) (16 Megabytes recommended);
16 Megabytes hard drive disk space; and
OCR for page 158
-->
a compact disk (CD-ROM) drive (internal or external) or floppy disk drive.
The NRC model requires the following software:
Windows version 3.1 or higher, Windows for Workgroups 3.11 (Windows 95 or NT recommended),
NRC model CD or floppy disks.
To Install This Software From The CD
Insert CD into drive. Setup will begin automatically if you are using Windows 95. If not, locate the "setup" folder (directory) named "Disk 1."
If you are using Windows 3.1, you will need to locate the "setup" folder (directory) named "Disk 1" on the CD to initiate the setup.
To Copy The Program From The CD To Floppy Disks
General instructions: Insert the CD. Locate the 13 disk folders (directories) on the CD. Copy all files in each folder to individual disks inserted into your floppy drive. You will need 13 individual floppy disks. You may also copy the contents of the CD to a directory on your hard drive and subsequently copy the 13 folders onto individual disks inserted in your floppy drive.
Using Windows 95: Use Explorer to locate your CD drive. Click on folder named "Disk 1." On the right-hand side you will see all files contained in this folder. Press "Alt-A" to select all files in this folder. Next, make sure your mouse is located over the selected files and RIGHT CLICK your mouse. Select "Copy" and move to the disk drive A: and PASTE onto the floppy disk located in drive A. Label this as "Disk #1." Repeat for each of the 13 disks, labeling each with the appropriate disk number.
Using Windows 3.1: Use File Manager to copy as described above.
To Install This Software From Floppy Disks
Enter Windows.
Select Program Manager.
Select File.
Select Run.
Insert NRC "Disk 1" into floppy drive.
Type "A:/SETUP" on the command line.
Press Enter.
Insert disks as prompted.
Getting Started
After you have installed the NRC model, an icon will be added to your workspace, if you are using Windows 3.1. If you are using Windows 3.1, double click on that icon to open the model software. If you are using Windows 95, select "Programs" and then select "NRC" to begin.
An introductory screen will appear. After reading the statement of use, click "OK"
When the main menu screen appears, choose one of the program options on the screen (Gestation, Lactation, Growth) to select the desired program. Note: preferences for the use of either digestible energy (DE) or metabolizable energy (ME) for inputs should be selected as well as preference for the use of "tool tips" (use of these tips is recommended). Preferences on this main menu screen should be selected before beginning the model programs.
To view and print the feed composition tables, Adobe Acrobat Reader is required. To activate this software from the CD (or if the software currently exists on your computer) click on the utilities button located on the menu bar of the NRC model. You will be presented with the option of installing or providing the location of Adobe Acrobat Reader. Select the installation option to activate Acrobat Reader. Once this software is installed, click on the "tables" button on the main menu bar to view and print the feed composition tables. You can also access and download Adobe Acrobat Reader software onto your computer by going to the Internet address: www.adobe.com
OCR for page 159
-->
2 Using the NRC Model Programs
Program features of the NRC model are presented in the following examples. These tutorials describe how to choose inputs and how to obtain, interpret, and apply outputs.
NRC Model Program MAIN MENU SCREEN
OCR for page 160
-->
Position the cursor over the appropriate program option and click or press {ENTER} to select that program.
About The Screen
From the main menu select the NRC model Growth program. The user will be presented with a screen that can be viewed as having three functional sections. Along the bottom is the task field with a series of task bars (Figure 1). Above the task field you will find the screen is divided into two equal sections; the report field on the right (Figure 2), and the folder field on the left (Figure 3).
Task Field
FIGURE 1
Screen for the Growth program with task field highlighted.
Reports
Allows the user to view the results of the program computations. The user can view input data, calculations, and nutrient requirements specific to the program used. Reports are given for basic calculations, true ileal digestible amino acids, apparent ileal digestible amino acids, total amino acids in a corn—soybean meal diet, minerals, vitamins, and fatty acids, by clicking on the A, B, C, D, E, F, or G button at the bottom of the report field, respectively. The report heading button allows the user to input a title for the report printout.
Min/Max
Changes the screen in the report field to allow input of new minimum and maximum parameter values. Within this screen, the user can also change the incremental step by which increases and decreases in values can be made using the arrow functions or the keyboard arrows. The user can also set the number of decimal places appearing in a parameter. After a change is made in the input range, incremental step, or decimal places, the appropriate save button becomes activated. Changes must be saved before moving to another parameter in order to retain the change.
OCR for page 161
-->
Conversions
Changes the screen in the report field to display the U.S. standard equivalents to the units displayed in the folder field.
Enter Dietary Energy Intake
Allows the user to calculate the nutrient requirements based on an actual energy intake or on the model's default energy intake.
Report Based On
Allows the user to view the nutrient requirements on an amount-per-day basis or on a diet concentration basis.
Auto Calc—Off
Allows the user to determine whether to have the program recalculate requirements after each input, or only after manually activating recalculation function. (Recommend setting to the "off" position when using slower machines.)
Reset
Returns all parameters to their original default values.
Feed Tables
Allows the user to access the feed composition tables.
Help
Allows the user to access help screens.
Preview
Allows the user to preview the report results of the model being used. This option provides a view of results that occur from changing inputs. The report includes information provided by the user to generate the report and the calculated requirements on both a percentage basis and an amount-per-day basis.
Print
Sends the current version of the report associated with the model program being used to the printer selected in the Windows control panel.
Exit
Allows the user to exit the computer model and return to the main menu.
Report Field
This field contains three separate functional screens. The user may toggle between the three screens by clicking on either the Report, Min/Max, or Conversions buttons.
Report Screen
The report screen allows the user to choose the view of one of seven different reports by clicking on the appropriate button.
A
Basic calculations and input data
B
Amino acids on a true ileal digestible basis
C
Amino acids on an apparent ileal digestible basis
D
Amino acids on a total basis (applies to corn—soybean meal diet)
E
Minerals
F
Vitamins
G
Fatty acids
Report Heading
Report Heading allows the user to define the title of the report.
Parameter Setting Screen
The parameter setting screen allows the user to change values for parameter inputs. This screen is accessed by clicking the Min/Max button.
Conversions Screen
Provides the user with standard U.S. equivalents to metric units shown in the folder field. This screen is accessed by clicking the Conversions button.
Folder Field
Within the folder field, the user can move between the gestation, lactation, and growth folders by clicking on the appropriate folder tab at the top.
OCR for page 162
-->
FIGURE 2
Screen for the Growth program with report field highlighted.
FIGURE 3
Screen for the Growth program with folder field highlighted.
OCR for page 163
-->
3 Tutorial Lesson 1
General Description Of The Growth Model
All programs, including the Growth program, can be initiated by selecting the appropriate NRC model button on the opening screen. However, before selecting the appropriate model button, DE or ME should be selected as your preference of input values. Once in the desired model program, using your mouse or tab key, you can begin entering inputs (Figure 1). To move from one input cell to another, press the "Enter" or "Tab" keys.
Inputs
To change values for inputs, highlight the appropriate cell by sweeping over the cell with the cursor or by triple-clicking on the cell, input the desired value, and hit enter. When the cursor is over the cell, a minimum and maximum value for input will appear. Values outside this range will not be accepted. Small incremental changes may be accomplished by one of two methods. After highlighting the cell incremental increases or decreases in the value can be made using the up or down arrows on the keyboard. Alternatively, these changes can be made by clicking on the up or down arrows to the right of the value in the appropriate cell. After you have attained the desired value, hit enter to move the cursor to the next input cell.
Three other methods exist for moving between input cells. Any cell may be reached directly using the mouse cursor. You can move from one cell to the next using the tab key to move forwards, or use shift + tab to move backwards. Alternatively, the same task can be achieved using the left arrow key on the keyboard to move backwards and the right arrow key to move forwards.
It is very important to remember to hit the Re-Calc task bar every time that an input is made. Otherwise, the report will not be correct. If the Re-Calc bar is a red color, this means that an input change has occurred and that the equations must be recalculated.
Optional Inputs
The first entry is to indicate the caloric density of the diet, in kcal of DE per kg of diet assuming that DE was selected as the preferred input on the opening screen. Insert this value in the upper box. The default value is 3400 kcal/kg, which is the typical value for a corn–soybean meal diet.
The user should then indicate the weight of the pig. The model was developed for pigs weighing from 3 to 120 kg, and any weights outside this range may not have valid estimates of requirements.
Options exist for determining requirements of gilts, barrows, boars, or any combination of the three genders. This is attained by inserting the number of each sex in the appropriate box beside gilts, barrows, and boars.
The model uses a standard default lean growth curve for gilts, barrows, and boars, and this is done by pressing the radio button beside "std." Ordinarily, this is the lean growth curve that will be used. However, if the user prefers to use a different shape curve, that can be done also by pressing the button beside user. A new screen appears where you can enter the intercept and the coefficients of a cubic equation that best describes your alternative curve. A quadratic equation can also be used by using a zero as the fourth coefficient. Quadratic or cubic equations can be derived by using a spreadsheet program (See Appendix 3). Any new equations can be saved by pressing the appropriate buttons on this screen. Press "Return" to return to the main screen.
To incorporate the effect of stocking density (space per pig) or environmental temperature, click on the appropriate box. When successfully incorporated, a check mark will appear in the box. To remove the effects of space per pig or environmental temperature, click again on the box to remove the check mark.
The estimated requirements can be calculated with the option of either including the dietary energy intake or by excluding it and allowing the model to determine a default
OCR for page 164
-->
energy intake at a particular body weight. To change this from the default, click on the "Yes" option. Similarly, the program offers the option of having the reports given on a dietary concentration basis or on an amount-per-day basis. The default setting is for a dietary concentration basis. To obtain requirements on a daily basis, click on amount/day. At any time the user can return to the default settings by clicking on the "Reset" task bar.
Options exist allowing the user to view the general output or the requirements for amino acids on a true or apparent digestible basis or on a total basis, minerals, vitamins, and fatty acids by clicking on boxes A through G at the bottom of the report screen.
Conversion Factors
In addition to these features, the standard English equivalent conversions of the metric values can be viewed by clicking on the "Conversions" task bar in the task field. To return to the report screen click on the "Report" bar.
Maximum and Minimum Values
To view the minimum and maximum values that can be input, click on the "Min/Max" bar in the task field. To view the range for any parameter, click on the parameter cell of interest. The range of acceptable values can be changed. To change the value for any given parameter, click on either the minimum or maximum bar in the box labeled "input ranges" and input the new value. Save the new values before exiting the program. Within this screen, there also exists the option to increase or decrease the degree of incremental changes when using the arrows button option. The number of figures following the decimal point for any parameter can also be changed within this screen.
Grow-Finish Case Study
Begin the tutorial by selecting DE input values and then selecting the NRC Growth program. Both of these options are located on the main menu screen. At the Growth model working screen, enter information by placing the cursor in the appropriate cell. First, if the Re-Calc task bar says that it is on, turn it off. Otherwise, the program will recalculate between each entry and it will take several seconds for each recalculation. When you click on each input cell, the descriptor becomes highlighted; type information in highlighted cells. It may be necessary to sweep across the value with your mouse before entering the new number; or you can use the up and down arrows for minor changes. All entries are in metric units; conversions and conversion factors are available by clicking on the Conversion option, which displays information and converted equivalents in English units.
Dietary Energy Concentration
Enter the dietary digestible energy (DE) concentration of the diet in kcal of DE per kg of diet. This is on an "as fed" basis and assumes 90% dry matter in the diet. In this example, the dietary energy concentration is 3,400 kcal of DE/kg. For practical results, this value cannot be below 2,000 or above 5,000 kcal/kg. The default value for this entry is 3,400.
Daily Energy Intake
In this example, we will not enter DE intake, but let the model calculate it from the default equation. Press the radio button beside "no" in the lower left task bar.
Pig Weight
Enter the average weight of the pigs for which requirements will be determined. For this example, the average weight is 70 kg, so enter 70.
Distribution Of Sex
In this example, we will determine the requirement for a mix of barrows and gilt, assuming a 1:1 ratio. Enter a "1" in the space following gilts, a "1" in the space following barrows, and a "0" in the space following boars. If you enter 10 gilts and 10 barrows, you will get the same answer.
Lean Gain
The average lean growth rate of the pigs is now entered. Lean gain is defined as the carcass fat-free lean tissue gain averaged over the range of 20 to 120 kg body weight. This value is estimated from the final lean content of the carcass minus an initial lean content of the carcass divided by the number of days from start to finish. In this example, we will assume that the lean gain is 330 grams per day for gilts and 320 grams for day for barrows. Enter these two values beside gilts and barrows, respectively. It does not matter what value is entered beside boars, because we are not including any boars in this determination (i.e., the number of boars is 0).
Lean Growth Curve
We will use the default growth curve for both genders, so press the radio button beside Std for barrows and for gilts.
Space/Pig
We will enter the space allocation, so click on the box to the left of space/pig. Let's assume that there is 0.9 square meters per pig. Enter 0.9 in the box following space/pig. Note: Caution should be used in making adjustments for crowding because the adjustments are not precise. Adjustments may be too great at the lower end of each weight range category.
Temperature
We will enter 22 degrees C as an average temperature for these pigs. Check the box to the left of
OCR for page 165
-->
temperature and enter 22 in the box to the right of temperature. Click on the box marked Conversions, and you will notice that the space in more familiar units is 9.68 square feet and the temperature is 71 degrees Fahrenheit. Click on the box called "Reports" to return the main screen.
Go to the box marked "Report based on" and click the radio button next to "%" or "amount/kg."
You are now ready to look at the report. But, remember, it will not be correct until you first hit the Re-Cale task bar, which is red in color. Press it and after a few seconds, the task bar will say "Auto Calc Off."
Press box "A" under the report. You will now see much of the data that you have already entered. In addition, you will see the carcass daily lean growth rate and the whole body daily protein accretion rate of the pigs at the particular weight that you have chosen. The estimated whole body gain of protein tissue and fat tissue is also displayed. You will also see the DE and ME concentrations of the diet, the daily DE and ME intakes under the conditions that you have specified, the daily feed intake, and the expected daily gain and feed conversion efficiency (feed/gain) of the pigs at this particular body weight. The approximate crude protein level in the diet is also given. You will have to use the scroll bar on the right side of the screen to see the crude protein level of the diet.
Click on "B" and the amino acid requirements, on a true ileal digestible basis, are listed. Click on C for the apparent ileal digestible amino acid requirements, and click on D for the total amino acid requirements assuming that a corn-soybean meal diet is fed. Note that the total lysine requirement is 0.75% of the diet. Click on E, F, and G for the mineral, vitamin, and linoleic acid requirements, respectively.
Now click once again on D. Again, what you see are the amino acid requirements of a group of barrows and gilts (1:1 ratio) at 70 kg body weight with lean growth rates as you previously specified. Now go to the box marked "Report based on" and click on the radio button to the left of "amount/day." Note that the report screen now shows that the daily lysine requirement is 19.7 grams/day. Now go back and click on % or amount/kg.
Let's make some further changes to see what effect they have on the lysine requirement. Change the temperature, space/pig, lean growth rate of the pigs, number of pigs and you will see the resulting changes in the predicted lysine requirement. Click on the "Yes" button in the box marked "Enter Dietary Energy Intake" and reenter another daily energy intake. Note the change in the lysine requirement, as well as all of the other requirements when they are expressed on a concentration basis. This is because the feed intake changes; thus the concentration of nutrients must change to give an equivalent daily amount of that nutrient.
Note that when you make a change in energy concentration, space per pig, or temperature, a warning sign will appear. The warning indicates that with low-energy diets, pigs may not be able to eat sufficient feed to meet their predicted energy requirement and that with crowding or high temperatures, lean gain may be reduced.
Note that every time you make a change in any of the variables, the Re-Calc task bar below the report will be in bright red, and you must click on this bar in order for the model to make recalculations.
The recalculation box can be turned on or off. When turned on, recalculation occurs every time you make a change in your input, but it takes more time that way. When turned off, time consuming recalculations are avoided whenever you change an input, but you must remember to click on the box to recalculate.
Press the "Print" task bar and the report will be printed. If you want to assign a title to the report before printing it, press the "Report Heading" button and entire the desired title. The printed report for the conditions that you have entered is shown at the end of this exercise. If you want to view the report before it is printed, press the preview bar.
Anytime that you need help, hit the "Help" task bar and a help screen will appear. The index will first appear and you can click on the area that you need help and that area will appear. Or, you can scroll through the entire help screen.
If you want to exit the program, press "exit." If you want to access one of the other models, click on the appropriate tab at the top left of the screen.
OCR for page 166
-->
4 Tutorial Lesson 2
General Description Of The Gestation Model
The Gestation model is quite similar to the Growth model in terms of data entry and output of reports. The user is referred to the general description of the Growth model, discussed in the previous chapter for details.
Gestating Sow Case Study
Begin the tutorial by selecting the Gestation tab if you are already in one of the other programs or select Gestation from the main menu screen. Enter information by placing the cursor in the appropriate cell. First, if the Auto Calc is on, click on the task bar to turn it off. Otherwise, the program will recalculate between each entry and it will take several seconds for each recalculation. When you click on each input cell, the descriptor becomes highlighted; type information in highlighted cells. It may be necessary to sweep across the value with your mouse or triple-click on the cell before entering the new number; or you can use the up and down arrows for minor changes. All entries are in metric units; conversions and conversion factors are available by clicking on the Conversion option, which displays information and converted equivalents in English units.
Enter the energy concentration of your diet. Let's assume that you are feeding a diet with 3,200 kcal of DE per kg, which is slightly lower in energy than a corn—soy diet. Enter 3200.
Daily energy intake will be calculated by the model. If there is a value in this box, then go the lower part of the screen and find Enter Dietary Energy Intake and click on the "no" box. The energy intake entry box will now be blank.
Let's assume that the sow weighs approximately 180 kg at breeding and we want it to gain 45 kg of weight during pregnancy. Enter 180 and 45 in the appropriate boxes. Assume that the sow will farrow 13 pigs, so make that entry. In this instance, we will assume that there is no temperature effect, so the small check box beside temperature should be blank. If there is already a value in the temperature box, click on the check mark beside it and the temperature box will go blank.
Press the red "Re-Calc" button to make the calculations. Press the "A" box, and you will see the data that you entered. You will also see estimates of how the weight gain will be distributed, that is, 29.64 kg for the pigs and the placental tissues and 15.36 kg for maternal tissues. Of the maternal tissue, 14.64 kg is protein or lean tissue, and only 0.72 kg is fat tissue. The model predicts that the sow will consume 8809 kcal of DE per day, which is equivalent to 2.13 kg of feed per day.
Click on boxes B, C, and D for estimates of the amino acid requirements of this sow, on a true digestible basis, apparent digestible basis, and total basis, respectively. Note that the model predicts that the sow requires 0.52% total lysine in the diet. Press boxes E, F, and G to see the mineral, vitamin, and linoleic acid requirements.
Go to the "Report Based On" task bar and press "Amount/day." Now look at the reports after pressing B, C, D, etc. and you will see estimated requirements expressed on a daily basis.
What would happen if this sow were fed either more or less feed during gestation? Go to the task bar marked "Daily Dietary Energy Intake" and press "Yes." You can now enter DE intake in Mcal. Remember that there are 1000 kcal in 1 Mcal. Enter a different value, press the "Re-Calc" bar and observe the changes in pregnancy weight gain and nutrient requirements that result from this change.
To print the report, press "Print." If you want to assign a title to the report before printing it, press the "Report Heading" button and entire the desired title. An example of a printed report based on the original entries is shown in the attached gestation table.
OCR for page 167
-->
5 Tutorial Lesson 3
General Description Of The Lactation Model
The Lactation model is quite similar to the Growth model in terms of data entry and output of reports. The user is referred to the general description of the Growth model, discussed in Chapter 3 of this User's Guide for details.
Lactating Sow Case Study
Begin the tutorial by selecting the ''Lactation" tab if you are already in one of the other programs or select "Lactation" from the main menu screen. Enter information by placing the cursor in the appropriate cell. First, if the Auto Calc is on, click on the task bar to turn it off. Otherwise, the program will recalculate between each entry and it will take several seconds for each recalculation. When you click on each input cell, the descriptor becomes highlighted; type information in highlighted cells. It may be necessary to sweep across the value with your mouse or triple-click on the cell before entering the new number; or you can use the up and down arrows for minor changes. All entries are in metric units; conversions and conversion factors are available by clicking on the Conversion option, which displays information and converted equivalents in English units.
Enter the energy concentration of your diet. Let's assume that you are feeding a diet with 3,400 kcal of DE per kg; enter 3400.
Daily energy intake will be calculated by the model. If there is a value in this box, then go to the lower part of the screen and find Enter Dietary Energy Intake and click on the "no" box. The energy intake entry box will now be blank.
Let's assume that the sow weighs approximately 175 kg after farrowing and that we expect it to lose approximately 5 kg of weight during a 21-day lactation period. The sow will be nursing 10 pigs, and the average daily gain per pig will be 200 grams. Enter these values in the appropriate boxes. Let's assume that there will be no temperature effect so the small box beside temperature should not be checked. If there is already a value in the temperature box, click on the check mark beside it and the temperature box will go blank.
Press the red "Re-Calc" button to make the calculations. Press the "A" box and you will see the data that you entered. You will also see that the sow will probably lose about 1.9 kg of lean tissue and 3.1 kg of fat tissue during the 21-day lactation, and it will be expected to produce about 7.4 kg of milk per day. The model predicts that the sow will consume about 16,942 kcal of DE per day, which is equal to 4.98 kg of feed.
Click on boxes B, C, and D for estimates of the amino acid requirements of this sow, on an true digestible basis, apparent digestible basis, and total basis, respectively. Note that the model predicts that the sow requires 0.94% total lysine in the diet. Press boxes E, F, and G to see the mineral, vitamin, and linoleic acid requirements.
Go to the "Report Based On" task bar and press "Amount/day." Now look at the reports after pressing B, C, D, etc. and you will see estimated requirements expressed on a daily basis.
What would happen if this sow were fed more feed during lactation? Go to the task bar marked "Daily Dietary Energy Intake" and press "Yes." You can now enter DE intake in Mcal. Remember that there are 1000 kcal in 1 Mcal. Enter 18.5 Mcal, press the "Re-Calc" bar, and notice the increased feed intake. The sow now will gain about 1.1 kg of weight during lactation and the percentages of amino acids are less (the lysine requirement is now 0.90%) because feed intake is higher.
To print the report, press "Print." If you want to assign a title to the report before printing it, press the "Report Heading" button and entire the desired title. An example of a printed report based on the original entries is shown in the following lactation table.
OCR for page 168
-->
TABLE 1 Growth Model Report Printout.
OCR for page 169
-->
TABLE 2 Gestation Model Report Printout.
OCR for page 170
-->
TABLE 3 Lactation Model Report Printout.
Representative terms from entire chapter:
task bar
