Growth Monitor: Compare Heifers to Breed Standards

Spreadsheet tools for tracking dairy heifer growth in comparison to breed standards.
Growth Monitor: Compare Heifers to Breed Standards - Articles

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Introduction

One way to evaluate the success of a heifer-rearing program is by monitoring the height and weight of calves and heifers and comparing the results to breed averages for specific age groups. Although most dairy producers, consultants, feed industry representatives, and veterinarians can recognize under- or overconditioned animals, it is difficult to visually determine whether a heifer's height or weight is normal for her age. The only real way to tell how heifers are growing is to weigh and measure them several times a year and compare them to standards. With this information, managers can identify potential problems in the rearing program. Whole groups of animals that are undersized, underweight, or overweight indicate improper feeding or management.

The Growth Monitor spreadsheet series provides a set of tools to evaluate heifer growth. Options within the series provide flexibility for monitoring multiple or individual animals, plotting heifer body weight or withers height against current growth standards, and calculating average daily weight gains. In addition, hip heights may be entered and evaluated for Holstein heifers.

This article describes operating and interpretation procedures for the Growth Monitor files. In each spreadsheet, the breed and units of measurement can be selected from a drop down menu. Links to all of these tools are provided at the end of this article.

Group Growth Monitor

  • Provides a snapshot comparing multiple heifers to recommended breed standards on a single measurement date.

Instructions

  1. Measure and record heifer body weight, withers height, and/or hip height (Holsteins).
  2. Open a new Group Growth Monitor file. A dialog box will open automatically with a message about macros. Choose to "enable macros". If you choose "disable macros", the spreadsheets will not work. If this dialog box does not open, you can change the default setting to disable macros. This allows you to choose whether or not to enable macros on a case-by-case basis (when you open the file).
  3. Click on the "Input" tab.
  4. Choose the breed and units of measurement from the drop down menus, and enter the measurement date and farm name.
  5. Enter identification information and growth measurements for each animal. Type over any example data present in the file. If you do not, the example will be included with your heifers and will affect your results. Enter data in cells containing blue text. Do not enter anything in cells with black text; these are formulas and changing them may cause them to stop working. You must enter an ID name or number and a group name or number for each heifer if you want to separate results by group.
  6. As you enter data, heifers that fall below recommended weights will be marked with a red "X" in the "Underweight Heifers" column. Similarly, heifers that fall below recommended heights will be marked with an orange "X" in the "Underheight Heifers" column. Check marked records for measurement accuracy, data entry error, or actual growth problems.
  7. Prepare graphs and summary table. Due to the spreadsheet's ability to handle a large number of heifers, most users will need to update the graphs and summary table. This is a simple matter of using pre-programmed commands called macros. Update the summary table by holding down "control" and typing "t". To display graphs display correctly, hold down "control" and type "h". This command hides all the blank rows in the "Input" sheet.
  8. View the summary table and graphs by clicking on the appropriate tabs at the bottom of the window. If the line for "Your Heifers" shoots off the scale or has extreme curves in it, see Step 7.
  9. If you need to enter more data into the spreadsheet, reveal hidden rows by holding down "control" and typing "u".
  10. The spreadsheet is currently set up to handle a maximum of 1200 heifers. Users can expand this number, but will have to make a few changes to maintain functionality. Detailed instructions for adding rows are provided in the spreadsheet files.
  11. Data for recommended weights and heights can be viewed on the Summary Table worksheet or by clicking on the "Recommendations" tab. Standards are based on the results of measuring a large number of heifers of various breeds throughout the United States. The Holstein population was part of a national USDA study conducted during 1991 and 1992. Most of the data was collected from herds in which the average age at first calving was slightly greater than 24 months. As a result, the heifers probably were smaller for any given age than those found on today's well-managed dairy farms that calve heifers at 22 to 24 months of age. Holstein growth standards are based on the median, 75th percentile, and 95th percentile of the national population. For all other breeds, the recommended growth ranges shown are the population mean plus one standard deviation. Hip height recommendations for Holstein heifers are also presented. These data are a compilation of USDA and Pennsylvania data sets and are available for Holstein heifers only. The range represents the population average plus one standard deviation above the average. These recommendations are based on a much smaller number of observations and, therefore, should not be interpreted as absolute standards.
  12. We suggest saving each measurement date as a separate file for future reference. It also may be useful to use the measurement date in the file name. This would be especially helpful to evaluate gains over time.
  13. Any worksheet may be printed by choosing "print" from the file menu.

Group ADG Monitor

    • Calculates ADG between two measurement dates for multiple animals.

Instructions

    1. Open a new Group ADG Monitor file. A dialog box will open automatically with a message about macros. Choose to "enable macros". If you choose "disable macros", the spreadsheets will not work.
    2. Click on the "Input" tab.
    3. Enter the farm name and two measurement dates.
    4. Enter identification name or number, birth date, and body weight on the two dates for each animal.
    5. If growth measurements previously have been entered into a Group Growth Monitor file and saved by measurement date, data can easily be found and copied into the ADG Monitor file. Sort data for both dates by ID number or name. Copy columns from the Growth Monitor file into the ADG Monitor file. Be sure to match information using ID number or name. Remember to paste in several steps to avoid copying over formulas.
    6. Type over any example data present in the file. If you do not, the example will be included with your heifers and will affect your results.
    7. Enter data in cells containing blue text. Do not enter anything in cells with black text; these are formulas and changing them may cause them to stop working.
    8. You must enter an ID name or number and a group name or number for each heifer if you want to separate results by group.
    9. Update the summary table by holding down "control" and typing "t".
    10. View the table by clicking on the "Summary Table" tab. Animals that were measured on only one of the two dates are automatically excluded from calculations of group averages. Animals that changed groups between measurements will be included in the average for their group on the second measurement date (that is, group averages are calculated for groups as of the second date).
    11. Any worksheet in the file can be printed by choosing "print" from the file menu.

Individual Growth Monitor

    • Compares growth of an individual animal to recommended breed standards over her lifetime.

Instructions

    1. Open a new Individual Growth Monitor file. A dialog box will open automatically with a message about macros. Choose to "enable macros". If you choose "disable macros", the spreadsheets will not work.
    2. Click on the "Input" tab.
    3. Enter the animal's identification information. Choose the breed and units of measurement from the drop down menus.
    4. Add growth measurements over time as they are taken.Type over any example data present in the file. If you do not, the example will be included with your heifers and will affect your results. Enter data in cells containing blue text. Do not enter anything in cells with black text; these are formulas and changing them may cause them to stop working.
    5. Prepare data for graphing by hiding blank rows; hold down "control" and type "h".
    6. View graphs by clicking on the appropriate tabs at the bottom of the window. Note: If the line for "Your Heifers" shoots off the scale or has extreme curves in it, see Step 7 under the Group Growth Monitor instructions.
    7. Before entering new observations, all hidden rows must be revealed; hold down "control" and type "u".
    8. Any worksheet in the file can be printed by choosing "print" from the file menu.

Multiple Measurements

    • Provides information about growth of multiple animals at a specific age over a period of time. This information differs from information gleaned from comparing the graphed results of two measurement dates. If the two graphs are compared, information about growth at specific ages over time can be seen. However, the advantage of the two-graph method is that management and feeding changes also can be detected and evaluated.

Instructions

    1. Measure and record heifer body weight, withers height, and/or hip height.
    2. Open a new Multiple Dates file. A dialog box will open automatically with a message about macros. Choose to "enable macros". If you choose "disable macros", the spreadsheets will not work. If this dialog box does not open, you can change the default setting to disable macros. This allows you to choose whether or not to enable macros on a case-by-case basis (when you open the file).
    3. Click on the "Input" tab.
    4. Select the breed and units of measurement from the drop down menus. Enter the measurement date and the farm name.
    5. Enter identification information and growth measurements for each animal. Type over any example data present in the file. If you do not, the example will be included with your heifers and will affect your results. Enter data in cells containing blue text. Do not enter anything in cells with black text; these are formulas and changing them may cause them to stop working. You must enter an ID name or number and a group name or number for each heifer if you want to separate results by group.
    6. Remove blank cells - they create problems for the graphs. Due to the spreadsheet's ability to handle a large number of heifers, most users will need to update the graphs and table. This is a simple matter of using pre-programmed filters. Go to the Summary worksheet. Each column has a filter that allows you to choose which cells to view. Click on the arrow button in the first row of any column and a list of filter options will appear. To remove blank cells, scroll to the bottom of the list and choose "NonBlanks." If one column has more blank cells than another, you may have to apply filters to more than one column to view graphs correctly. To remove a filter, click on the arrow button and choose "All."
    7. Update the Table worksheet. Go to the Table worksheet and click anywhere inside the first table. Go to the "Data" menu and choose "Refresh Data" (the red exclamation point icon). This icon also may appear on the Pivot Table toolbar.
    8. View graphs by clicking on the appropriate tabs at the bottom of the window. If the line for "Your Heifers" shoots off the scale or has extreme curves in it, see Step 6.
    9. The spreadsheet is currently set up to handle a maximum of 100 heifers measured 6 times. Users can expand this number, but will have to make a few changes to maintain functionality. Detailed instructions for adding rows are included in the spreadsheet file.
    10. Data for recommended weights and heights can be viewed on the Table worksheet or by clicking on the "Recommendations" tab. Standards are based on the results of measuring a large number of heifers of various breeds throughout the United States. The Holstein population was part of a national USDA study conducted during 1991 and 1992. Most of the data was collected from herds in which the average age at first calving was slightly greater than 24 months. As a result, the heifers probably were smaller for any given age than those found on today's well-managed dairy farms that calve heifers at 22 to 24 months of age. Holstein growth standards are based on the median, 75th percentile, and 95th percentile of the national population. For all other breeds, the recommended growth ranges shown are the population mean plus one standard deviation. Hip height recommendations for Holstein heifers are also presented. These data are a compilation of USDA and Pennsylvania data sets and are available for Holstein heifers only. The range represents the population average plus one standard deviation above the average. These recommendations are based on a much smaller number of observations and, therefore, should not be interpreted as absolute standards.
    11. Any worksheet may be printed by choosing "print" from the file menu.

Reading and Interpreting Results

All graphs show both recommended weight and height and the actual weight and height of heifers entered in the spreadsheet. Holstein graphs display three recommended lines. The bottom line (green) represents the median of the population. The middle line (blue) represents the 75th percentile, and the top line (purple) represents the 95th percentile. An achievable goal is to keep a majority of heifers near the 75th percentile and the entire herd ranging between the median and the 95th percentile. Graphs for other breeds display only two lines. The bottom line (green) represents the mean, while the top line (blue) represents one standard deviation above the mean. An achievable goal is keeping a majority of heifers near the top of this range and the entire herd above the mean (bottom line).

Research has shown that heifers large enough to calve at 22 to 24 months old with acceptable levels of milk production must be near or above average in size. Keep in mind that producing extremely large heifers may not result in increased lifetime milk production. Growing extra large heifers also increases feed expenses, because daily energy requirements increase with body size. It also is important to realize that calving age is highly correlated to the profitability of the animal, and that body weight after calving (1,250 pounds for Holsteins) is highly correlated to first lactation milk production. The objective of a heifer-raising program is a relatively constant rate of growth. Rate of gain from 2 months of age to puberty should target 1.75 pounds per day. Growing heifers above or below this target will result in reduced milk production in the first lactation (and perhaps throughout her lifetime).

Holstein heifers should reach 750 to 800 pounds and 48 to 50 inches by breeding age (13 to 15 months). After calving, heifers should weigh 1,137 to 1,296 pounds and measure 52 to 55 inches at the withers. Recommended breeding heights and weights for all heifers are shown in Table 1.

Table 1. Suggested weights and heights for breeding-age heifers.
BreedBody Weight (pounds)Withers Height (inches)Hip Height (inches)
Jersey525 to 57543 to 4545 to 47
Ayrshire700 to 75046 to 4848 to 50
Guernsey700 to 75046 to 4948 to 51
Milking Shorthorn750 to 80046 to 4848 to 50
Holstein750 to 80048 to 5050 to 52
Brown Swiss750 to 80048 to 5150 to 53

Growth charts can help evaluate heifer management and can flag problem situations, such as entire groups of animals that are undersized, underweight, or overweight. Low- or poor-quality forages (hay and silage) generally are responsible for inferior growth performance in young heifers, but lack of a balanced grain supplement and overcrowded housing can add to the problem. Underfed calves do not receive adequate energy and protein to meet their growth requirements. Inadequate housing and ventilation can contribute to poor growth by causing subclinical respiratory problems, and can negate an adequate feeding program. The level of management and sanitation also can affect heifer growth.

Adequate weight but restricted skeletal growth may occur in a particular age group. Relying on poor-quality hay and corn silage for all or most of the heifers' diet usually causes this problem. Both of these forages typically have low protein, mineral, and vitamin levels. Feeding cereal grains with very little protein, mineral, and vitamin supplementation along with these forages may exacerbate the problem.

Feeding 2 to 4 pounds of grain per day and balancing the diet for protein, energy, minerals, and vitamins can solve a feeding problem, often within several months. Rations must be more than adequate, however, if heifers are to compensate with increased growth rates.

Overweight animals with normal skeletal growth for a their age group are another common scenario. Although heifers as young as 6 months of age may appear fat, this problem is more common in breeding-age heifers. Marginal to adequate dietary protein combined with excessive energy intake most often causes fat heifers. This can result from feeding free-choice corn silage and moderate levels of supplemental grain. Problems generally arise on farms where good- to excellent-quality forages are produced and fed to heifers in unrestricted amounts. Restricting heifers' intake of these high-quality forages usually corrects the problem.

Summary

Healthy, productive herd replacements are the result of good management that starts before calves are conceived and continues until they enter the milking herd. Proper attention to the entire process ensures that genetically superior animals with maximum potential for milk production enter the herd.

Growth Monitor Spreadsheets

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