Introduction
In this part of the nutrient grids series, we bring everything together to formulate a complete calf ration including grain, forage, and liquid feeds. We’ll walk through how to use the nutrient grids to introduce different feeds and adjust nutrients accordingly.
Grain Program Setup
We begin with the grain program. Starting at the top menu, we select the grain program and then choose the feed composition.
To facilitate visibility, the window is moved to the side, allowing us to view feed composition, daily performance, and the graph simultaneously. On this farm, two types of grain feeds are used: a starter and a grower. The grower is of slightly lower quality, with 14% protein on an as-fed basis. Both the starter and the grower have a dry matter content of 90%.
To convert the 14% protein to a dry matter basis, we divide 14 by 0.9, giving us approximately 15.56% protein. This value is pasted directly into the cell using the calculator tool. Similarly, the 3% fat content is converted by dividing by 0.9, resulting in 3.33%.
Other nutrient values are adjusted as needed. For example, starch content is increased to around 20%. Amino acids like arginine and histidine are removed from view since they’re not a priority in this scenario. The calcium and phosphorus values are also displayed for monitoring. The nutrient grid allows alphabetizing nutrients, making it easy to locate and focus on specific ones.
Grain Feeding Program
Once the grain compositions are set, we configure the feeding program. The starter feed has a slightly higher cost compared to the grower. Feeding begins at birth and transitions to the grower feed with a 10-day transition starting on day 50.
The farmer prefers not to exceed 3 kg of starter feed per day. Once calves reach that limit, their forage intake will naturally increase. As the values are updated in the nutrient grid, the ration adjusts accordingly.
Forage Program
In this particular simulation, the forage used is wheat straw instead of sorghum hay. Wheat straw has about 5% protein and 75% NDF on a dry matter basis.
After updating the feed composition, some unexpected results appear in the program. By default, the forage intake was set at 100% starting on day 45, which is not practical. Since the calves are fed forage ad libitum, we adjust the percentage to a more realistic value of 8%. This means that calves will consume around 8% of their diet as forage until they reach the maximum grain intake, at which point forage intake increases further.
Liquid Feeding Program
The farm uses three types of liquid feeds: colostrum, transition milk, and a milk replacer. While the base ration includes similar feeds, this farm specifically uses a milk replacer with a 24/18 composition (24% protein, 18% fat).
The milk replacer values are converted to a dry matter basis. For instance, 24% protein divided by 0.95 gives us 25.26%, and 18% fat becomes 18.9% on a dry basis. These values are updated accordingly in the nutrient grid.
Liquid Feeding Schedule
The farm uses a straightforward feeding program, which is simplified into five steps. Costs are input: colostrum and transition milk are free, and milk replacer is set at around $3 per kilogram.
- Days 1–3: Calves receive only colostrum and transition milk.
- Day 4–10: Calves begin receiving 650 grams of milk replacer daily.
- Days 11–49: Milk replacer is increased to 800 grams per day.
- Days 50–56: Intake is reduced to 400 grams per day (once daily) before weaning.
The final feeding period is added, with day 56 marking the end of liquid feeding. All steps are visible and easily managed within the feeding grid.
Summary
This walkthrough demonstrates how nutrient grids can be used to adjust feed composition and feeding schedules for grain, forage, and liquid feeds. By updating nutrient values and configuring step-by-step feeding programs, we can build a complete, practical ration tailored to the needs of the farm and the growth goals for the calves.