Proper design of restraint equipment is essential to prevent stress on animals during handling, stunning and slaughter. A small design mistake which may appear to be insignificant to the engineer can be extremely detrimental to animal welfare. Operators of restraint equipment must be properly trained. Cattle will place their heads into stanchion (yoke) or chin-lift types of head-restrainers if they are gently moved forward by a rear pusher gate. Cattle confined in an upright ASPCA pen for religious slaughter will remain calmer if the apparatus is gently closed around them. The vertical travel of the belly lift should be restricted to 71 cm (28 in) — it should not lift the animals off the floor. The rear pusher gates should be equipped with a separate regulator to prevent excessive pressure from being applied. Stunning or ritual slaughter should be carried out within 10 seconds of the animal’s head being restrained. The modified ASPCA pen described in the paper was seemingly humane when operated by people concerned about animal welfare.
Grandin, T., UFAW, Volume 1, Number 2, May 1992 , pp. 85-90(6)