Unsupervised exploratory cluster analysis of free range laying hens to determine the use of aviary feed chains and range access

Abstract

Clustering is a common data mining methodology used for improved subject understanding. The aim of this study was to identify sub-populations oflaying hens housed in an aviary system to understand the use of feeding chains which can affect hen performance and welfare. A total of 5,641 Lohmann Brown free-range laying hens placed amongst 3 commercial flocks equipped with a 3-tier aviary system were individually monitored using radio- frequency identification (RFID) technology. Individual body weights of all hens were obtained at 16, 22, and 72 weeks of age. K-Means cluster analysis optimised with the Calinski-Harabasz Criterion was performed. Hens of cluster 1 (n=2442 hens) spent significantly more time on the lower tier feeding chain (14.5 ± 2.36 hours/hen/day) compared to hens of cluster 2 (n=2083; 6.9 ±2.4 h/hen/day) and hens of cluster 3 (n=1116; 2.0 ± 1.9 h/hen/day), respectively (