Hi All, I had to put down a hen today and wanted to share a little-used method (in the US) that I found to be very humane. I have researched a lot on the subject, and I have personally used the ax method, cervical dislocation, CO2, and now Argon. The first 2 methods if done accurately are humane, and it is certainly not my intent to dispute anyone using these methods. What I would like to do is provide an alternative to those of us who find those methods hard to carry out. CO2 gas is painful to a chicken's airways unless in low percentages, in which case it takes several minutes for the chicken to die. I do not recommend trying it. Argon is an inert gas. If used to kill a chicken, it is humane so long as the chicken is breathing in less than 2% oxygen (Dr. Raj Mohan). Someone from *unmentionable-see rules* recommended a blend called Stargon to me, but I used straight up Argon with success. You need to prepare in advance, before you have a crisis or planned butcher day. It is best to have a chamber pre-filled with Argon to put the chicken in. I did not have that sophisticated of a set up so I used a low box in a large clear plastic bag, put the chicken in, pushed out as much air as I could, then filled the bag with argon using a tube attached to the bottom of the box on one end and the argon nozzle on the other. The chicken showed no signs of distress breathing in the argon. She got wobbly after about 30 seconds, then did some flapping, though I think she was already unconscious when the flapping started. She stopped breathing and moving about 15 seconds after the flapping started. It probably would have taken less time had I created a more tightly controlled environment to regulate the gases, according to the studies I have read. Despite not having the ideal set up, she suffered very little if at all. I don't think I succeeded in creating an environment with <2% O2, so I would recommend improving on my method rather than following it exactly. Studies have been done that show you can bleed out a chicken completely after argon killing, though it takes longer than the ax or throat cutting method. Gas killing is common in the UK for meat chickens and perfectly safe when inert gases are used. There is a very good paper called AVMA Guidelines on Euthanasia that you can Google if you want to learn more. One point they make in the guidelines about bleeding animals to death is; "Because of the anxiety associated with extreme hypovolemia, exsanguination should be done only in sedated, stunned, or anesthetized animals (AVMA, June 2007)." One downfall to the argon method is that it requires preparation and financial investment. They do sell and make these chambers for killing several birds at a time for thousands of dollars. If you are able to make your own chamber, you can buy or lease a tank of argon or Stargon for probably under $200. I bought a small tank off of EBay for $20 and spent $32 to fill it. My tank is quite small and I emptied it on the one bird, so I will be purchasing a larger one for future use. Anyway, I wish you and your flock well and hope this posting is beneficial.