Effects of hatching on-farm on behaviour, first week performance, fear level and range use of organic broilers

Abstract

Hatching on-farm is an alternative to traditional hatching in the hatchery where incubated eggs are placed on the farm on embryonic day 18 for hatching to take place. Thus, several hatchery procedures and transport of newly hatched chicks are avoided, and chicks have access to feed and water immediately after hatching. In the present study, the aim was to examine the behaviour, first week performance, fear level and range use of hatching slower-growing organic broilers on-farm (OF). Chicks hatched in the hatchery (HC) and transported to the farm were used for comparison. The study included six flocks of both treatments, each consisting of approximately 3600 mixed-sex Hubbard JA57 ColorYield broilers, housed with veranda and range access. Compared to HC, the body weight was consistently higher for OF chicks at 0 h, 24 h, 48 h and D7 relative to arrival of HC chicks (P < 0.001). Feeding was more frequently observed in OF than HC chicks at 11 h and 35 h (P < 0.024). Generally, more HC than OF chicks were drinking (P < 0.001), and more OF than HC chicks were resting during the first 23 h (P < 0.016). The crop content differed between treatments at 6 h, 12 h, 24 h and 36 h, but not at 48 h: At 6 h, OF chicks had higher odds of having water (odds ratio (OR) = 2.45; P < 0.001) and lower odds of having feed in the crop (OR = 0.16; P < 0.001). In addition, they had higher odds of having an empty crop at 6 h (OR = 3.01; P < 0.001), 12 h (OR: = 1.56; P = 0.018) and 36 h (OR = 2.56; P < 0.001). Reduced fear of humans was found during the first week for OF chickens when assessed in a stationary person test (P < 0.030). OF chickens also tended to express less general fear than HC chickens in a novel object test (D7, D28, D53 and D60; P = 0.052). However, contrary to expected, the reduced general fearfulness expressed by OF chicks in the novel object test did not result in increased veranda and range use (P = 0.92 and P = 0.45, respectively). To conclude, on-farm hatching of slower-growing broilers appears to benefit animal welfare as, during early age, it reduces fearfulness and allows for more resting and feeding, likely being the cause of increased body weight.