As an alternative to traditional hatching in the hatchery, fertilized incubated eggs can be placed in the rearing barn on embryonic d 18 for hatching to occur on-farm, omitting several hatchery procedures, and transport of day-old chicks. In addition, this practice further allows newly hatched chicks access to feed and water immediately post-hatch. The aim of the present study was to examine welfare implications of hatching slower-growing organic broilers on-farm (
OF
) using the One2Born system (One2Born, Uden, the Netherlands). Hatchery-hatched chicks (
HC
) transported to the farm were used as control. Six flocks of both treatments, each comprising approximately 3,600 mixed-sex Hubbard JA57 ColorYield broilers, housed with veranda and outdoor access were included in the study. Compared to HC, the hatchability was higher in OF chicks (95.3% vs. 94.8%;
P
= 0.0097), whereas the number of second grade chicks was lower (11.6% vs. 16.1%;
P
< 0.0001). The chick quality was lower for OF than HC (odds ratio: 1.79;
P
= 0.0009), but this was not reflected in the first week mortality (OF: 0.41%, HC: 0.99%;
P
< 0.0001) or total mortality (OF: 1.51%, HC: 2.20%;
P
< 0.0001). No difference was found between treatments for the live body weight at slaughter age (
P
= 0.73). Breast blisters were more common in HC males than in OF males and in females from both treatments (
P
= 0.038), whereas OF males and females from the 2 treatments did not differ (
P
= 0.91). There was no effect of treatment on litter quality, footpad dermatitis, gait, skin injuries, and rejection rates at slaughter (
P
≥ 0.35). In conclusion, OF hatching appears to be a viable concept, resulting in reduced mortality and increased hatchability, though knowledge on the topic is sparse. Therefore, more research should be addressed to the welfare implications of hatching OF, specifically to impacts on litter quality, footpad dermatitis, and how chick quality impacts other animal welfare indicators.
