Two major welfare problems can occur during slaughter without stunning. They are a prolonged period where the bovine remains sensible and aspiration of blood into the trachea (windpipe) and respiratory tract. Blood entering the respiratory tract is a welfare concern because the sensation caused by blood entering the respiratory system is likely to be very distressful.
Observations and research done by Neville Gregory, Ph.D., from Bristol Univ. in the UK, and other researchers indicates that cutting cattle close to the jawbone will eliminate the transmission of “potentially unpleasant sensory signals associated with blood contaminating the upper and lower respiratory tract.” When the cut is made close to the jawbone in the C1 (Cervical 1) position, the sensory nerve to the respiratory tract is severed. However, most Halal and Kosher cuts are made further away from the jaw in the C2 to C4 position. In this position, the sensory nerve remains intact and distressful sensations could be transmitted to the brain before the animal loses sensibility. These research findings were presented by Gregory at the Centenary International Symposium held in Portsmouth, England. This conference was hosted by the Humane Slaughter Association.
Cutting in the C1 position close to the jaw will also help prevent prolonged periods of sensibility caused by sealing off of the artery ends. Approximately 3 percent to 5 percent of the cattle have delayed onset of insensibility, according to Gregory. This small percentage is similar to observations I have made in plants that have expert Kosher slaughter. Most cattle that have delayed onset of insensibility will have occluded arteries caused by false aneurysms. Cutting close to the jawbone in the C1 position greatly reduces the formation of false aneurysms. When cattle were cut in the C1 position, only 1 percent of the arteries were occluded. When they were cut in the C3 position, which is further away from the jaw, one-third of the cattle had false aneurysms. Switching the position of the cut to the C1 position has the potential to greatly improve animal welfare.
Some Halal slaughter is already being performed by cutting close to the jawbone. In Halal, cutting in the C1 position is strongly recommended. For Kosher slaughter, the knife is not permitted to touch the jawbone. Research is needed to determine if Kosher cuts that are ritually correct will reliably sever the nerve to prevent distressful sensations from aspirated blood from being perceived by the cattle. Gregory concluded, “changing to a cut at C1 could partly reduce the potential for suffering during slaughter without stunning.”
Differences in anatomy
The problems discussed in this article mainly occur in cattle. Due to differences in anatomy, sheep and goats bleed out more quickly than cattle. Gregory also found that sealing off of the artery ends does not occur in sheep and goats. Numerous researchers have documented that cattle lose sensibility within 17 to 85 seconds. Insensibility can be prolonged if the arteries get sealed off. Sheep become unconscious in two to 14 seconds. These new findings on the advantages of cutting in the C1 position have the potential to improve animal welfare when slaughter is performed without stunning.
Dr. Temple Grandin operates Grandin Livestock Systems Inc., Fort Collins, Colo., and is a faculty member in the animal science department at Colorado State Univ.