SwiftWeigh: A Rapid Calf Weighing System Using Top-Down 2D Point Cloud Data

Shuning Wang; Weijian Hu; Liyong Zhou; Minchao Li; Lizhen Cui; Yi Zhang; Jingfang Si; Yongxing Du

Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

SwiftWeigh: A Rapid Calf Weighing System Using Top-Down 2D Point Cloud Data

Shuning Wang , Weijian Hu, Liyong Zhou, Minchao Li, Lizhen Cui, Yi Zhang, Jingfang Si, Yongxing Du

Abstract

Context. Accurate calf weight measurement is essential for effective health management and production optimisation in dairy farming. Existing non-contact methods include 2D image-based approaches, which are easy to deploy but often suffer from low precision, and 3D point cloud-based methods, which offer higher accuracy but are computationally intensive and less practical for real-time applications. Aims. This study aims to develop a lightweight, accurate, and efficient calf weighing system that balances speed and precision by leveraging top-down 2D point cloud data. Methods. We propose SwiftWeigh, a system that captures overhead point cloud frames using a stereo camera and projects them into 2D images while preserving essential spatial features. A convolutional neural network (CNN) is employed to detect keypoints and derive body measurements such as shoulder width, abdominal width, height, area, and a newly defined rump width (distance between the hip and buttock regions). These measurements are input into an ensemble regression model comprising Gradient Boosting, ElasticNet, and Ridge regression for predicting calf body weight. Key results. SwiftWeigh was validated on a dataset of 100 Holstein calves, each with five frames. It achieved a root mean square error (RMSE) of 4.51 kg and a mean absolute error (MAE) of 4.04 kg, surpassing several existing methods in prediction accuracy. The system demonstrated efficient performance with minimal computational overhead. Conclusions. The proposed method delivers state-of-the-art accuracy while ensuring rapid processing and low system requirements, making it suitable for real-world dairy farm applications. Implications. SwiftWeigh provides a non-invasive, accurate, and scalable solution for calf weight measurement. Its low-stress, real-time capability enhances on-farm monitoring, supporting better decision-making in modern dairy management systems.

AN25230 Accepted 20 September 2025