Bok.

Welfare Ranking of Bird Reactions During Insensibility Induction

Behavior	Ranking
No change in behavior from the time the birds enter the gas until they fall over (lose posture)	Excellent
Gasping only, with no other change in behavior from the time the birds enter the gas until they fall over (lose posture); Most birds with no wing flapping and a few birds with weak intermittant flapping	Acceptable
Gasping, combined with continuous wing flapping from the time the birds enter the gas until they fall over (lose posture)	Not Acceptable
All birds flap continuously or attempt to climb out of the container from the time the birds enter the gas until they fall over (lose posture)	Serious Problem

Animal Welfare Evaluation of Gas Stunning (Controlled Atmosphere Stunning) of Chickens and other Poultry