Swedish researchers have found that stress during commercial hatching affects growth production and feather pecking in laying hens.
Every year, billions of layer chicks worldwide are hatched under industrial circumstances. Researchers at Linkoping University, Sweden, investigated how the stressful procedure in the commercial hatchery, including incubation, hatching, processing and transport, affects them.
The traits were compared to those of a control group hatched in a small incubator and handled gently in a quiet room without any processing and transport. The chicks were weighed at hatch and at an additional 8 time points: 4 days, 1 week, 2 weeks, 5 weeks, 8 weeks, 20 weeks and at 25 weeks.
Feather-pecking was studied at 15 weeks and damages to the feathers and injuries to the comb and wattle were assessed at 25 weeks of age. From 19 weeks, eggs were collected 3 days per week, counted and weighed.
The results found that chicks from a commercial hatchery had a lower hatch weight than control chicks. At 20 weeks, the weight of commercially hatched chicks were still numerically lower, although this did not reach statistical significance.
Commercially hatched chicks tended to show more feather-pecking behaviour at 15 weeks of age compared to control chicks (p<0.1), although feather condition at 25 weeks of age showed the opposite pattern. there was no difference in comb and wattle injuries.></0.1),>
Looking at production, the scientists found commercially hatched chickens laid fewer (p<0.05) and smaller (p><0.05) eggs than chicks hatched and handled under calm circumstances.></0.05)></0.05)>
The research concluded that stressful incubation, hatching and handling of chickens in a commercial hatchery was related to reduced post-hatch weight and a tendency for reduced weight gain. And, commercially hatched chicks had a reduced egg production and a tendency for increased feather-pecking behaviour. A poorer feather condition in control chickens could possibly be the result of environmental impact rather than related to hatchery effects.
Effects of stress during commercial hatching on growth, egg production and feather pecking in laying hens has been published in the journal