Automated tracking of broiler breeder activity and functional area use in a commercial housing system: differences between sexes and time of day

Broiler breeders are in the EU traditionally housed in large flocks, yet little information is available regarding the birds' movement patterns in these flocks and their use of functional areas within the house (e.g., nest boxes, litter area). This exploratory study aimed to gain some first insights into individual differences in spatial area use of broiler breeders under commercial conditions, using an ultra-wideband (UWB) tracking system. The broiler breeder house (59 × 14 m; 826 m²) under study housed 5,600 Ross 308 breeder females and 350 Ross 308 breeder males and consisted of two compartments that the birds could not move between, each containing three functional zones: a litter area, an elevated slatted area, and a nest box area. A small subset of birds was fitted with a backpack containing an UWB tag, and data on 7 male (M) and 8 female (F) birds from 52 to 55 weeks of age were examined here. Four aspects of activity and functional area use were investigated: 1) overall area use, 2) distances moved, 3) relative time spent in functional areas, and 4) consistency in resting locations at night. On average, broiler breeders used more than half of the area available to them within a day, although this varied between individuals and/or days. In general, M birds covered larger distances in a day than F birds, and distances moved were larger during the light period (04:00-17:00) and transition period (17:00-17:30) than during the dark period (17:30-04:00). Furthermore, M birds spent less time in the nest and slats zones, and more time in the litter zone, than F birds. No differences between the sexes were observed in the average distance between resting locations at night. Although the sample size was very limited and these findings should therefore be considered as preliminary, they do offer a first step towards providing insight into broiler breeders' movement patterns and preferred locations, which can in the future inform housing design and management.