Introduction

The ME (Metabolizable Energy) requirements and supply chart is located in the center of the science screen. The X-axis represents the day of age, ranging from 14 to 112 days, while the Y-axis displays the mega calories of metabolizable energy per day. The chart consists of three series: the ME intake, shown by dark blue squares; the ME maintenance, represented by light blue bars; and the ME requirement for gain, indicated by dark green bars.

As we analyze the chart, we observe that the ME requirement and intake generally increase as the calf ages, from 14 days to 112 days. A quick evaluation shows that early in life, the intake is lower or equal to the requirements, but by the end of the simulation, the intake exceeds the requirements for both maintenance and growth.

It is important to note that the requirement for gain is based on the target average daily gain required. Changing the settings to adjust the calculation of the target average daily gain will alter these targets. For instance, switching from a polynomial to a fixed calculation of the target average daily gains results in a recalculation of the growth rate, which leads to slight changes in those values.

As we modify the feeding program, such as changing the fat composition of the grower feed, we can observe the impact on the ME intake. For example, setting the fat composition from 3% to a more extreme 15% results in a significant increase in ME intake, especially toward the end of the growth period.

The chart provides a valuable evaluation of the overall energy composition of the diet and how well it meets the animal’s requirements. Like other charts within GPS, if we left-click on the ME requirements and supply chart, we’ll see a short red flash, indicating that the data behind the chart has been copied to the clipboard. If we paste it into another application, we can view the values there. Similarly, a right-click on the chart triggers a green flash, signaling that the picture of the chart has been copied as well.