VentVision: A Multimodal Vision-Based System for Automated Vent-Based Chick Sexing

Marta Veganzones-Rodriguez1, Thinh Phan1, Arthur F. A. Fernandes2, Vivian Breen2, Jesus Arango2, Michael T. Kidd1, and Ngan Le1

1 University of Arkansas · 2 Cobb-Vantress, Inc

Abstract

Chick sexing has been a crucial practice for many years due to the need for early gender identification in poultry production. Traditional methods, such as vent sexing, are highly effective but labor-intensive, requiring expert knowledge and years of training, making it a challenging and time-consuming process. Moreover, skilled professionals are increasingly scarce, making the process difficult to scale. To address this challenge, we proposed VentVision, an automated vision-based classification system that leverages computer vision and deep learning techniques to improve the efficiency and scalability of chick gender classification. Our system follows a four-step pipeline: multi-modality video capture, temporal segment selection, vent region detection, and gender classification, automating vent-based sexing. We evaluated our approach using RGB imaging, infrared (IR) imaging, and a multimodal RGB-IR feature-level fusion framework based on a dual-stream architecture. The multimodal model achieved an accuracy of 98.09%, outperforming single-modality approaches. These results demonstrate that VentVision achieves expert-level chick sexing performance while eliminating the need for years of specialized training, with manual handling limited to vent exposure, thereby simplifying the sexing workflow.

System overview

Overview of the VentVision pipeline
Overall pipeline of the proposed VentVision system, consisting of four main components: multi-modality video capture, temporal segment selection, vent region localization, and gender classification.

Experimental setup

RGB and infrared camera setup for VentVision
The setup used two side-by-side Reolink 842A cameras, one recording RGB and the other infrared video, positioned approximately 50 cm from the target area. A light source mounted above and aligned with the cameras provided uniform illumination during recording.

Dataset statistics

VentVision dataset statistics

Qualitative results

Grad-CAM++ heatmaps for the VentVision system
Grad-CAM++ heatmaps show that the model consistently focuses on the vent region, where sex-specific anatomical features are located. For males, attention is concentrated on the small white cloacal bump, highlighted with a green circle, while female predictions rely more on patterns within the inner vent region. Each example presents the original RGB image alongside its corresponding heatmap.

Quantitative results

Table 1 summarizes the RGB-based gender classification results across five folds. ResNet-50 achieves an average ID-level accuracy of 97.17%, with precision, recall, and F1-score also consistently exceeding 97%. Fold 3 reaches 100% accuracy, demonstrating that RGB images contain distinctive visual features for gender classification, while the lower accuracy in fold 0 may reflect greater variation in lighting and chick positioning.

VentVision Table 1 quantitative results

Table 2 presents the infrared-based classification results. The model achieves a slightly higher average ID-level accuracy of 97.46%, with folds 1, 2, and 3 reaching 100%. Since predictions from multiple images are aggregated for each chick, the ID-level evaluation provides a more stable classification decision and demonstrates strong generalization to unseen individuals.

VentVision Table 2 quantitative results

Table 3 reports the results of the RGB–infrared feature-fusion model, which jointly learns from paired features extracted by two ResNet-50 backbones. The multimodal approach achieves the best overall performance, with an average accuracy of 98.09%, precision of 98.60%, recall of 97.07%, F1-score of 97.80%, and AUC of 99.18%. No fold falls below 96% accuracy, and the fused model outperforms both RGB-only and infrared-only approaches, confirming that the two modalities provide complementary information and improve classification consistency and robustness.

VentVision Table 3 quantitative results

BibTeX

@article{rodriguez2026ventvision,
  title={VentVision: A Multimodal Vision-Based System for Automated Vent-Based Chick Sexing},
  author={Rodriguez, Marta Veganzones and Phan, Thinh and Fernandes, ArthurF A and Breen, Vivian and Arango, Jesus and Kidd, Michael T and Le, Ngan},
  journal={Smart Agricultural Technology},
  pages={102236},
  year={2026},
  publisher={Elsevier}
}