Huts are a favored enrichment of birds in broiler houses and can have a positive impact on welfare, according to University of Arkansas research.
The effect is even more profound when the enrichment is combined with variable lighting regimes, suggested the results of the study,1 presented at the 2023 International Poultry Scientific Forum.
In the work using 4,800 broiler chicks, scientists led by program associate Seong Kang, PhD, tested bird engagement with three different enrichments — ramp, perching board and hut — in either consistent 20 lux light or variable light, where feed lines were lit at 40 lux and side walls at 2 to 5 lux.
Investigators found that in pens that featured huts as the enrichment, the engagement of birds was significantly greater than in pens containing the perching board and ramp.
Daily activity and numbers of dust bathing holes — an indicator of natural behavior — were shown to be greatest in pens with huts in the house with variable lighting, while numbers of birds that needed to be culled due to a leg health issue were lower in pens with huts under both lighting regimes than those with the other enrichments.
Combined factors have profound effects
In a follow-up experiment, the researchers sampled birds kept in 20 lux light with huts and variable light with and without huts, testing their brains to assess for specific welfare indicators. Eight birds were sampled at 14, 28 and 42 days of age.
They used quantitative PCR testing to measure a number of molecular indicators of welfare, observing indicators associated with higher stability and both lower stress susceptibility and chronic social stress in birds in variable lighting areas which also had access to the hut enrichment. This suggests a positive combined effect of the two measures, the scientists suggested.
“It would be very practical for producers to make average light intensity to the birds under the feedline about 40 lux and at the sidewall or middle of the house about 2 to 5 lux, with a huge impact for the cost,” Kang said.
“It brings the best welfare of broilers and a great quality of meat. I propose that this is because birds perceive light information through deep brain photoreception, and it may change their behavior and physiological response.”
1 Kang S, et al. Effect of environmental enrichments on behavior, leg and mental health of broilers in the commercial houses. International Poultry Scientific Forum, 2023, Atlanta, USA.