AAAP: Can controlled atmosphere stunning be used for Halal slaughter?

16 December 2025

1 minute read

By: Chris Wright

North America

The recently updated mandatory technical regulations regarding Halal slaughter regulation (UAE.S. 993/2022 “Animal Slaughtering Requirements According to Islamic Rules”), states that methods used to induce loss of consciousness in animals must not result “in heart stop of the animal” which would impede normal blood loss during slaughter, and that death of the animal is “caused by bleeding out during the slaughter process, not because of the loss of consciousness method.” 

Determining that there is heart activity beyond the controlled atmosphere stunning (CAS) process could potentially make broilers eligible for Halal slaughter, which has not historically been the case. 

Ken Opengart, Three Birds Consulting, LLC; Dianna Bourassa, Bourassa Consulting, LLC and researchers at Auburn University, USA, presented the results of a study at the 2025 annual meeting of the American Association of Avian Pathologists.

The study had two objectives: 

1. Evaluate the duration of rhythmic cardiac activity of market-age broilers following CAS. 

2. Evaluate whether there is sufficient duration of rhythmic cardiac activity post-CAS stunning to render broilers dead from volumetric blood loss. 

Electrocardiograms of market-age broilers were evaluated following CAS system exit. Rhythmic heart activity as measured was present in male broilers for an average of 390 ± 90 seconds, and in female broilers for an average of 366 ± 68 seconds. A typical time between CAS exit and entry into the scalder is 265 seconds.

These results demonstrate that rhythmic heart activity persists in market-age broilers after CAS-stunning for a period of time longer than necessary for a stunned bird to succumb from blood loss during normal stun and kill procedures, ensuring welfare and religious slaughter requirements are met so that meat from these broilers can enter appropriate Halal markets.