During the AAAP Welfare Meeting at the 2019 IPPE, Ryan Moyle described advanced technology applying carbon dioxide for mass euthanasia as an improvement on traditional “kill carts”. The installation uses a three-step conveyer system to obviate piling and to induce stress-free unconsciousness and euthanasia over a two-minute period. The module which can operate at 10,000 to 12,000 hens per hour subjects hens to progressively higher levels of carbon dioxide extending from an initial 30 percent to 70 percent concentration.
The Hen Sleeper was scientifically evaluated by Iowa State University in 2018. The system was 99.9 percent effective in inducing insensibility as evaluated using 11,000 hens. It was concluded that the Hen Sleeper is a humane and practical technology to depopulate caged flocks and conforms to the requirements outlined in AVMA guidelines for carbon dioxide euthanasia.
The benefits apart from welfare include lower labor requirements although the capital investment for equipment imposes costs for depreciation, interest, maintenance that may be a deterrent to more extensive adoption unless mandated by regulations imposed by states or customers. In a subsequent posting, EGG-NEWS will develop a projection of actual costs given that each unit costs $50,000 and operates at 2,000 hens per hour. To clear a house of 240,000 hens would require 40 operating hours with a projected total output of 6,000 hens per hour with three machines operating using a crew of three per unit.