NASCalf – Supply Calculations
Hello, and welcome to this NASCalf Knowledge Base video. In this episode, we’ll review the Supply Calculations window, which is found in the Diagnostics section of NASCalf.
The Nutrient Requirements and Supply window is accessed from the Diagnostics screen by selecting Supply Calculations from the menu. When you click this option, a new window opens titled Daily Nutrient Requirements and Supply. This window reports detailed information about intake, nutrient supply, and requirements for a single day of the simulation.
The day of age displayed is selected using the drop-down list in the upper left corner of the screen. For this example, we’ll look at day 30. When a new day is selected, all values in the window update automatically to reflect intake, nutrient supply, and animal performance on that specific day.
Let’s walk through the sections of this window, starting in the upper left. This section is labeled Model Parameters. Here you’ll find basic information describing the simulation on the selected day, including birth body weight, environmental temperature, and the results of the growth calculations. In this example, the calf gained 0.68 kilograms on day 30. You’ll also see the metabolizable protein allowable gain, which is 0.68 kilograms, and the metabolizable energy allowable gain, which is 0.70 kilograms.
Directly below is the Ration Information section, shown on a dry matter basis. This section summarizes the overall diet composition for the selected day, combining both liquid and dry feeds into a single total ration. This allows you to quickly see the nutrient profile of the complete diet being consumed.
On the far right side of the window are two sections showing Cumulative Intake and Cumulative Growth. These values are summed from day one through the selected day. In this example, by day 30 the calf has consumed 23.5 kilograms of dry matter from liquids, 3.3 kilograms from grain, and no forage. Below that, cumulative growth from birth to day 30 is shown. In this case, calves gained 16.25 kilograms over the first 30 days, and the average daily gain over that period is reported along with related performance metrics.
In the lower right section, you’ll see the Ingredient Composition of the diet. Using the drop-down menus at the top of this section, you can switch between liquids, grains, or forages, and you can also choose which nutrient category to display, such as energy, protein, or macro- or micro-minerals. This allows you to examine the detailed composition of each component of the diet on the selected day.
Now let’s look at the center top section, which provides a detailed summary of daily intake and nutrient supply. At the top of this section, you’ll see dry matter intake from liquids, grains, and forages, along with total intake for the day. On day 30, the calves consumed 0.86 kilograms of liquid dry matter, 0.30 kilograms of grain dry matter, and no forage, for a total dry matter intake of 1.16 kilograms.
To the right, you’ll see energy intake reported in megacalories. In this example, total energy intake on day 30 was 4.89 megacalories. Next to that is metabolizable protein supply, broken out by liquids and dry feeds and shown as a total. Here, 205 grams of MP came from liquids and 50 grams from grain, for a total of 255 grams.
Additional calculated values are also displayed, including crude protein intake, gross energy intake, the ratio of metabolizable energy to gross energy, the ratio of metabolizable protein to crude protein, dietary crude protein percentage, and the average metabolizable energy concentration of the feeds offered.
In the section directly below, we see the animal requirements for the selected day. Maintenance metabolizable energy requirement is 2.23 megacalories. The energy required for growth at the actual average daily gain of 0.68 kilograms is 2.6 megacalories, for a total requirement of 4.82 megacalories. Since energy intake was 4.89 megacalories, energy supply exceeds requirement by 0.07 megacalories. This indicates that energy is not limiting growth on this day.
Looking at metabolizable protein requirements, maintenance requires 49 grams and growth requires 206 grams, for a total of 255 grams. The difference between supply and requirement is zero, meaning protein supply exactly meets the requirement for a gain of 0.68 kilograms per day. In this case, metabolizable protein is the limiting nutrient for growth.
At the top center of the window, you’ll notice a checkbox that allows you to switch between actual average daily gain and target average daily gain. When this box is checked, requirements are recalculated based on the target gain rather than the simulated gain. In this example, the target average daily gain is 0.7 kilograms per day. When we switch to target gain, we see that energy supply is 0.02 megacalories short and metabolizable protein supply is 6 grams short of what would be required to achieve that target. This feature allows you to directly compare actual versus target performance and identify which nutrients are limiting progress toward your goals.
Finally, the bottom center section shows the hypothetical amino acid supply from liquids, dry feeds, and microbial crude protein. For each amino acid, requirements for maintenance, gain, and total are listed, along with an indication of whether supply is in excess or deficit. These calculations are covered in more detail in other NASCalf Knowledge Base videos.
Overall, the Supply Calculations window is a powerful diagnostic tool. It allows you to identify the nutrients limiting growth on any specific day of the simulation, while also providing detailed information on diet composition, cumulative intake, and cumulative growth.
That concludes this NASCalf Knowledge Base video. Thanks for watching, and be sure to explore the other Knowledge Base resources to learn more about using NASCalf effectively.
