Introduction
GPS is a desktop program designed to simulate the intake and growth of young calves. As such, it can provide important insights into many aspects of growth and identify important bottlenecks in the feeding program.
Based in NASEM
The base composition of the software if the “Calf Model” developed as part of the 2021 Nutrient Requirments of Dairy Cattle by the National Academy of Sciences, Engineering, and Medicine (NASEM). The nutrient requirement calculations and many of the nutrient supply calculations were derived directly from Chapter 10 of the Publication, the software included with the book purchase (including the computer code provided in supplemental materials) or in the “Model Description and Evaluation” chapter. Discrepancies in specific equations were tested and the most reasonable result selected.
The Calf Model in NASEM predicts dry feed intake, nutrient requirements, and nutrient supply on one day and predicts growth allowed by intake of metabolizable protein (MP) and metabolizable energy (ME). It does not simulate growth over multiple days. Further, the number of adjustments to the model are limited to feeding of vegetable protein in CMR and the reduction in dry feed digestibillity to to immaturity of the rumen during the transition from monogastric to ruminant phase. Therefore, the Team at Calf Notes Consulting felt that a new approach was needed – one that provided greater flexibility and options to predict growth during an extended period.
Stand Alone Program
The program was designed to work on a user’s “local machine” – the computer in their home or office – rather than a web-based program. While web-based programs are increasingly popular, the intensity of the calculations and relatively complex graphics suggested that the prediction model would be a “heavy load” for a web based platform.
GPS Package
The GPS program is a package of files copied to the user’s hard drive. In addition to the .exe file, there are a number of support files used to manage access and several of the controls that appear on various dashboards (windows). Also, the package comes with default files, a feed library, and other miscellaneous files needed for the program to run.
Updates
GPS is housed on the Microsoft Store – you can find the link on the GPS Home Page. Microsoft provides for automatic updates – so when a new version of GPS is available, Microsoft will inform the user and will automatically update the software with the latest version. This eases the task of keeping the program up to date.