The chicken sheds I research in are massive—measuring over three-quarters the length of a football field and 20 meters wide. Within each house, we rear approximately 28,000 nearly identical broiler chickens, the type used for meat, in six-week production cycles. My research is focused on enhancing the welfare of these birds. This involves exploring various factors such as lighting adjustment, perch design improvements, and comparing different breeds. Considering the large number of animals housed together, it is crucial to evaluate how changes impact the entire flock. Given that broilers are typically considered as a relatively uniform group due to selective breeding for meat production, it is practically impossible to monitor an individual broiler under commercial conditions without sending someone to follow it for weeks. To overcome this challenge, researchers either monitor a subset of birds and assume they represent the entire population or keep a group of broilers in a controlled setting, apply changes, and hope the conditions are similar enough to obtain valid results. However, what if we want to understand how individual broilers perceive their environment? In collaboration with Locatify, an Icelandic software company, we at Queen’s University Belfast’s Animal Welfare Unit have been working on adapting a commercial indoor tracking system to precisely locate individual chickens within a house in real-time. By attaching specially designed backpacks to the chickens, we gained insight into the unique characteristics of each bird, which could ultimately drive improvements in meeting their welfare needs. Our research findings have been published in Scientific Reports.
The ultra-wideband tags utilized to track the chickens’ movements are typically used for monitoring forklifts in warehouses or attached to lanyards to track individuals in office or museum settings. Ultra-wideband is a radio technology that determines an object’s position with an accuracy of up to 30cm by measuring the time it takes for a signal to travel from a transmitter to a receiver. The tags were small enough to be placed in specially designed chicken backpacks, allowing us to track their movements over several weeks. This system provided valuable data on their locations and activities, offering a comprehensive understanding of how they utilized the house.
When I shared this concept with one farmer, he pointed at a corner of the house and confidently stated that he saw the same chicken in that spot every morning. Another farmer believed that the chickens roamed freely throughout the entire house. Surprisingly, both observations were correct. Despite the apparent homogeneity of the chickens and their surroundings, significant differences in movement patterns were revealed. In our initial trial with the tracking system, we monitored 17 chickens and discovered that while one mostly stayed within 10 meters of the original tag location, another explored over 97% of the house in a single week. To further examine their preferences, we collected and then released the tagged birds after the initial observation period. Some chickens returned to their original areas, while others did not. It was interesting to note that three out of nine chickens returned to the back of the house within 24 hours, while the remaining five never revisited their original spots throughout the production cycle.
The observed variation in broiler movements prompted us to investigate the factors influencing their behavior. Previous studies have indicated that heavier and older birds, as well as those with leg issues, tend to be less active. However, we struggled to establish a conclusive link between these factors and the movement patterns of our tagged broilers. Although the two heaviest broilers explored the house the least, there were lighter birds that utilized less space. Additionally, we found that one broiler with a limp covered 69% of the house, while a lighter broiler with a normal gait occupied 43%. While there was a general decrease in activity as the birds aged, this trend was not consistent across individuals. Interestingly, there was no clear correlation between space usage and activity level, indicating that broilers exploring a smaller area moved around just as much as those utilizing a larger space. Although our results did not yield the expected graphical representations, they provided evidence that broilers may be more diverse in their behaviors than previously believed. As with most animals, it is reasonable to assume that chicken behavior is influenced by individual personality traits. Bolder broilers may be more inclined to explore the house extensively, while more timid ones might be easily startled and therefore tend to move around frequently. It is also possible that some chickens possess better spatial awareness or are more predisposed to forming social bonds. To gain further insights into these individual differences, we plan to continue utilizing this tracking technology and further investigate how specific broilers utilize space and how environmental changes can be implemented to optimize welfare for both individual birds and the entire group.