LiGAPS-Beef, a mechanistic model to explore potential and feed-limited beef production 3: model evaluation

Area of Science:

• Animal Science
• Agricultural Modeling
• Sustainable Production Systems

Background:

• Beef production systems face challenges in maximizing yield due to various biophysical limitations.
• Understanding and quantifying these limitations are crucial for improving efficiency and sustainability.
• The Livestock simulator for Generic analysis of Animal Production Systems - Beef cattle (LiGAPS-Beef) model aims to address these challenges.

Purpose of the Study:

• To evaluate the performance and accuracy of the LiGAPS-Beef model using independent experimental data.
• To assess the model's ability to simulate key factors influencing cattle growth and production.
• To validate the model's utility for identifying and mitigating yield gaps in beef production.

Main Methods:

• Model calibration using existing data.
• Validation of the LiGAPS-Beef model with independent experimental data from diverse global locations (Australia, Uruguay, Netherlands).
• Analysis of model performance based on simulated versus measured average daily gains (ADGs) and identification of limiting factors.

Main Results:

• The LiGAPS-Beef model demonstrated acceptable accuracy, with a mean difference of 137 g/day (20.1% of measured ADGs) and a root mean square error of 170 g/day (25.0% of measured ADGs).
• The model successfully simulated daily growth-limiting factors including genotype, heat stress, digestion capacity, energy, and protein deficiency.
• Simulated limiting factors aligned well with reported occurrences during experimental periods.

Conclusions:

• The LiGAPS-Beef model's accuracy is sufficient for understanding potential and feed-limited cattle production across diverse global systems.
• The model effectively identifies biophysical factors limiting growth, providing valuable insights for management strategies and yield gap analysis.
• LiGAPS-Beef serves as a robust tool for enhancing beef production efficiency and sustainability worldwide.