Hatching on-farm under field conditions -a comparison of fear-related response and urofecal glucocorticoid metabolite levels in broiler chicks hatched on-farm and in the hatchery.

Broiler chicks are usually hatched in hatcheries, sorted, and transported to farms, which can cause stress. Alternatively, transporting eggs to farms and hatching chicks in their future environment may reduce stress and affect their behavior. The study was conducted on conventional farms to evaluate whether on-farm hatching can improve animal welfare. Behavioral responses to humans and novel objects, as well as stress levels measured by urofecal glucocorticoid metabolites (ufGCM) were compared between on-farm hatched (OH) and hatchery-hatched (HH) broiler chickens. Slow-growing broiler chickens were monitored on 1 farm comprising 2 houses, each containing approximately 5,700 chickens. Production parameters were recorded over 7 production periods (PP). The Human Approach Test (HAT) and Novel Object Test (NOT) were performed on day of life (DL) 1 and 7 and latency parameters were assessed (n = 7 PP). Fecal samples for ufGCM analysis were collected at DL 0, 1, 2, 4, and 5 (n = 2 PP). More OH chicks were counted in HAT on both observation days than in HH. A significant difference in latency to enter the 1 m radius was observed between DL 1 and 7 (P = 0.015). For NOT, significant latency differences appeared between hatching groups (25 cm radius: P = 0.004; touch: P < 0.001) and for touch latency between DL (P < 0.001). HH chicks showed slightly higher ufGCM values than OH chicks. Both groups started with a high ufGCM level on DL 1 (OH = 1,526.73 ng/g; SD = 439.63 ng/g; HH = 1,730.72 ng/g; SD = 399.84 ng/g), which dropped to approximately 400 ng/g at DL 4 and DL 5. The only difference in the production parameters was found in live weight at DL 1, 7, and 42 (OH > HH, P < 0.001). This field study showed that chicks hatched on-farm were more accustomed to humans, less fearful, and exhibited slightly lower stress hormone levels than hatchery-hatched chicks. However, a larger sample is needed to confirm these findings.