Evaluating the impact of age, sex, and lameness on the problem-solving ability of broiler chickens

Abstract

Problem-solving abilities help individuals analyze, understand and solve challenges effectively. These abilities are important for adaptability and environmental changes. This study aimed to evaluate how sex, age, and lameness affect problem-solving abilities of broiler chickens. A total of 75 broiler chickens (Ross 708), 39 females and 36 males underwent three different problem-solving tasks at 14, 28 and 42 days of age. Birds were tested individually and in groups. Birds were given five minutes to solve the task. Latency of the first movement, latency of the first interaction with the task, duration to solve the task, number of attempts and their success rate were measured. Gait score (GS) was determined for each bird after the problem-solving task. For individual birds, age impacted the latency to first movement and latency to first interaction, with birds at 14 and 28 d taking longer than birds at 42 d. Birds at 42 days solved the task faster and had a higher success rate, then birds at 14 d (0.54 and 0.31, respectively). There was also a difference in sex, with males being faster to interact with and solve the task, as well as being more successful at solving the task then females (0.47 and 0.37, respectively). GS only impacted the duration, birds with a GS of 0, 1, and 2 (183.3s, 201.5s, and 194.9s, respectively) solved the task faster than birds with GS of 3 (216.1s). Pathway analysis showed that birds that took longer to interact with task were more likely to complete the task, birds who took longer to solve the task were less likely to succeed, and birds that made more attempts were more likely to succeed. Presence of conspecifics impacted the success rate, birds presented the task in groups (0.89) were more successful than individually (0.69). Paired success outcomes of birds tested individually and in groups, showed that 56% were successful both in a group and individually and 40% were successful in a group but not individually. The likelihood of success on the task increased when birds were in a group, indicating a social effect. Sex, age, and presence of conspecifics all impact problem solving abilities. Broilers already have problem-solving skills at 14 d and this improve with age.