Interpretation of the American Meat Institute (AMI) Animal Handling Guidelines for auditing the welfare of cattle, pigs, and sheep at slaughter plants

Temple Grandin
Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523, USA

Updated October 2011

The American Institute guidelines which uses objective numerical scoring was first developed in 1997. The use of this objective scoring system for auditing animal welfare has resulted in great improvements. In 1999 before McDonald’s Corporation and Wendy’s International started auditing animal welfare only 30% of the plants rendered 95% or more of the cattle insensible with a single shot from a captive bolt stunner. Today over 90% of the plants that are regularly audited by a customer can do this. Over the years, auditors, plant managers, and customers have had many question s on the interpretation of the guidelines and how to do scoring. In the paper I have taken the 20 most common questions and answered. The questions are based on actual experiences in plants or questions from auditors, plant managers, and customers.

Frequently Asked Questions

Question 1: To pass a welfare audit does a plant have to have a passing score on all seven of the core criteria?

Answer: YES - To maintain an acceptable level of animal welfare a passing score on all seven of the core criteria is required. They are: 1) Effective stunning, 2) bleed rail insensibility, 3) slipping and falling, 4) vocalization, 5) electric prod use, 6) willful acts of abuse, and 7) access to water. The secondary audit items should not be used to determine whether a facility passes or fails an audit.

When a single audit is done in a very small plant, some adjustments in scoring have to be made to adjust for a small sample size. On a sample of 10 cattle or less they are allowed one non-compliance on falling, stunning, and vocalization. They must get a perfect score on 2 out of 3 of these variables. When data is pooled the standard scoring for 100 cattle should be used. The table below will assist in scoring small plants.

Recommendations for Scoring Based on Cattle Sample Size
When data is pooled, use 100 cattle sample percentages
Number of animals per audit 100 Cattle 50 Cattle 25 Cattle 10 Cattle or less
Stunning efficacy 95% 96% 96% *see note
Vocalization 3% 4% 4% *see note
Insensibility 0% 0% 0% 0%
Slipping 3% 4% 4% 10%
Falling 1% 2% 4% *see note
Willful Act of Abuse 0% 0% 0% 0%
Dragging Sensible Animals 0% 0% 0% 0%
Clean Water Available Yes Yes Yes Yes
Adequate Footing Yes Yes Yes Yes
Internal Audit Frequency Min. Weekly Min. Weekly Min. Weekly Min. Weekly
3rd Party Validation Yes Yes Yes Yes
3rd Party Validation Frequency Annual Annual Annual Annual
* In a 10 cattle sample, 2 out of 3 of the * items must be 0%. They are allowed one non-compliance on * items.

Question 2: Is the audit failed if a truck driver who is not a plant employee beats and kicks animals?

Answer: YES - The guideline states: “Any willful act of abuse is grounds for an audit failure.”

Question 3: A single beef steer vocalizes (moo or bellows) 8 times. Since 8% is over the 3% limit for cattle vocalizations, does the plant fail on vocalization?

Answer: NO - On the five core criteria of stunning efficiency, insensibility, vocalization, slips and falls, and electric prod use, all scores are on a PER ANIMAL basis. When 100 animals are scored, each animal is checked off on a yes/no basis. Some examples are: 1) Silent cow or a vocal cow or pig 2) Poked with an electric prod or an electric prod not used 3) Fall or did not fall 4) Effectively shot with one shot or shot more than once

Question 4: An employee touches an animal with an electric prod, but does not push the switch to administer a shock. Does that count as electric prod use?

Answer: YES - Practical experience has shown that it is extremely difficult to determine if a shock was given. If the animal is touched with the electrical device it always counts. If a single animal is shocked more than once it still counts as one animal. The plant fails on electric prod use if more than 25% of the cattle or pigs are touched with it. Electric prods should never be used on sheep.

Question 5: If cattle, pigs, or sheep vocalize (moo, bellow, squeal or baa baa) in the stockyards (lairage) does this count on the vocalization score?

Answer: NO - Vocalization scoring is done in the following places:

pigs - restrainer, stun box, stun pen, and bleed rail
cattle - restrainer, stun box, religious slaughter box. Vocalization scoring is also done while cattle are entering the stun box or religious slaughter box. Vocalization caused by electric prod use is scored.
sheep - no vocalization scoring is done
For cattle, all vocalizations in the stun box, religious slaughter box, or restrainer count. In the lead up chute (race) and crowd pen, cattle vocalizations only count during actual movement of the cattle by a person.

Question 6: Does falling down in the stun box count when it occurs BEFORE stunning or religious slaughter?

Answer: YES - If more than 1% of the animals fall, this is a failing fall score. Boxes that are designed to cause sensible animals to fall down (trip boxes) should never be used. They would receive a failing score.

Question 7: Will a plant fail on falling if 5% of the animals fall during truck unloading?

Answer: YES - Slips and falls are scored during truck unloading. The guideline states: “Good animal welfare and quiet calm handling is impossible if animals slip or fall on the floor. All areas where animals walk should have non-slip footing. Animals should be observed during all phases of handling and if slipping or falling is observed, steps should be taken to correct the problem.”

Question 8: If an animal slips and its rear end touches the floor, is that scored as a fall?

Answer: YES - A fall is scored if any part of the body touches the floor during handling. The falling score is failed if more than 1% of the animals fall.

Question 9: A beef cow is rolled out of a stun box and the shackler sees eye movement and re-stuns it BEFORE hoisting. Is this scored as a second shot?

Answer: YES - The stunning audit would be failed if the employee had hoisted the animal before the second shot. Since the employee re-stunned the animal before hoisting; it is scored as a second shot. It counts as a point on core criteria 1 on effective stunning. To pass the stunning audit the employee has to be able to effectively stun 95% of the cattle with a single shot.

Question 10: A pig vocalizes (squeals) when the electric stunning wand (tong) is accidentally energized before it is fully pressed against the animal. Does this count as a point off the pig vocalization score?

Answer: NO - This will count as a “hot wand” and will be a point off on the “hot wand” section of the electric stunning score. Hot wand scores over 1% fail on stunning. Hot wanding is a welfare issue because the sensible pig feels the shock.

Question 11: A pig squeals when it is halfway into the restrainer or stun box due to an electric prod. Does this count on the vocalization score?

Answer: NO - The pig’s rear must be past the restrainer entrance to count. A score of over 5% of the pigs vocalizing in the restrainer fails on vocalization. The reason why pigs are only scored in the restrainer is due to difficulty of counting individual pigs squealing in other parts of the facility. Cattle are scored for vocalization in both the stunning area and the lead up chutes during handling because counting individual cattle that vocalize is easier than identifying individual pigs.

Question 12: A plant employee starts to skin the head of an animal that has blinking eyes. Is the audit failed?

Answer: YES - This is an automatic audit failure. The guideline states, “There is a zero tolerance for beginning any procedure like skinning the head or leg removal on any animal that shows signs of return to sensibility.” This applies to both conventional and religious slaughter. Animals with eyes that do spontaneous natural blinking are sensible.

Question 13: The CO2 machine malfunctions and several pigs wake up on the bleed table, get up and attempt to jump off. Is the audit failed if an employee shackles and hoists these pigs to keep them from running away?

Answer: YES - This is an automatic audit failure. The guideline states: “Any sensible animal on the bleed rail constitutes an automatic audit failure.” It is obvious that these pigs were fully sensible.

Question 14: A beef cow is shot with a captive bolt and appears to be rendered insensible. It is hoisted onto the bleed rail. On the bleed rail the auditor observes that the tongue is moving in and out which is a sign of possible partial return to sensibility. It is not fully sensible at this point. The auditor follows it down the bleed rail to make sure the tongue movement’s stop before dressing procedures start. At the start of dressing procedures the animal had sufficient blood loss to eliminate the tongue movements. Is this a failed audit?

Answer: YES- According to a strict interpretation of the guideline wording this could be interpreted by some people as passing, because the animal is probably still insensible. The problem is that these weak signs are indicators of the beginning of the process of returning to sensibility. These weak signs are an indicator of poor stunning. They can be eliminated by better stunner maintenance or storing cartridges for a cartridge fired stunner in a dry place. It is my opinion that standards for return to sensibility must be strict. On audits I have conducted I failed several plants for nose twitching (rabbit nose) or slight tongue movements. All of these plants were able to abolish these movements. Many USDA inspectors would issue a citation NR for these movements. Allowing these weak signs to pass is not acceptable because it allows a less effective stunner to be used. This reduces the margin of safety and increases the probability that a fully sensible animal could be dismembered. Any animal that is showing any indicator of return to either full or partial sensibility must be immediately re-stunned.

Question 15: An animal’s rear leg is kicking while it is hung on the bleed rail. Is the audit failed?

Answer: NO - Kicking may occur in totally insensible animals; it is just a reflex. People evaluating insensibility must look at the head. Refer to the AMI guideline for detailed instructions on determining insensibility.

Question 16: A pig falls down and becomes non-ambulatory on the unloading ramp. The truck driver drags it out of the way so that he can unload the rest of the pigs. Is the audit failed?

Answer: YES - Dragging a sensible animal is an act of abuse and is grounds for automatic audit failure. Dragging a sensible animal is also a violation of the Humane Slaughter Act. Animals must be rendered insensible with a stunning device BEFORE dragging, or a sensible animal can be carefully rolled onto a sled or other device for moving it.

Question 17: A steer rears up and knocks the electric prod out of an employee’s hand, and the end of the prod accidentally hits another steer in the eye. Is the audit failed for an act of abuse?

Answer: NO - The guideline clearly states that acts of abuse have to be done intentionally. The guideline states under core criteria 6: “Any willful act of abuse is grounds for automatic audit failure. 1) dragging a conscious, non-ambulatory animal; 2) intentionally applying prods to sensitive parts of the animal like the eyes, ears, nose or rectum; 3) deliberate slamming of gates on livestock; 4) purposeful driving of livestock on top of one another; 5) hitting/beating an animal. Note any such acts observed.”

Question 18: A plant that conducts religious slaughter shackles and hoists live animals BEFORE the throat is cut. Does this plant fail the audit?

Answer: YES - The AMI guideline states: “Cattle, calves, sheep or other animals that are ritually slaughtered without prior stunning should be restrained in a comfortable upright position. For both humane and safety reasons, plants should install modern upright restraining equipment whenever possible. Shackling and hoisting, shackling and dragging, trip floor boxes, and leg clamping boxes should never be used. In a very limited number of glatt Kosher plants in the United States and more commonly in South America and Europe, restrainers that position animals on their backs are used. For information about those systems and evaluating animal welfare, refer to (Ritual Slaughter Section). The throat cut should be made immediately after the head is restrained (within 10 seconds). Small animals such as sheep and goats can be held manually by a person during the ritual slaughter. Plants that conduct ritual slaughter should use the same scoring procedures except for stunning scoring, which should be omitted in plants that conduct ritual slaughter without stunning. Cattle vocalization percentages should be five percent or less of the cattle in the crowd pen, lead up chute, and restraint device. A slightly higher vocalization percentage is acceptable because the animal must be held longer in the restraint device compared to conventional slaughter. A five percent or less vocalization score can reasonably achieved. Scoring criteria for electric prod use and slipping on the floor should be the same as for conventional slaughter.”

Question 19: The employee stunning pigs with an electric stunner places the wand (tongs) on the middle of the pig’s neck and body on 10% of the pigs. Is the stunning audit failed?

Answer: YES - Electric stunners must be placed so that the current goes through the brain. Stunning on the neck bypasses the brain and will not induce instantaneous insensibility. To pass the stunning audit the wand (tong) must be placed in the correct position on 99% of the animals. Refer to the guideline for more detail.

Question 20: The animal moves it's head and the captive bolt stunner is shot in the air. Is this counted as a second shot?

Answer: NO - A stunner shot that shoots in the air does not count. If the bolt of the stunner touches or partially penetrates the animal, it is counted as a missed shot.

Question 21: How do you score plants that routinely shoot bulls, bison, and other heavy livestock twice? Do they fail?

Answer: NO - To verify that 95% or more are rendered insensible with one shot from a captive bolt, the auditor must check for signs of insensibilty BEFORE the second shot and record the stunning score. To pass the audit, 100% must be rendered insensible before hoisting or the beginning of dressing procedures.

Question 22: A plant claims to have a new type of electric stunner where an animal is rendered insensible because rythmic breathign is absent, but other signs of return to sensibility are present, such as vocalization and natural spontaneous blinking. Is the audit failed?

Answer: YES - To pass the insensibility audit, all five of the indicators of returning to sensibility must be absent. They are: 1) rythmic breathing, 2) vocalization, 3)natural spontaneous blinking like live animals in the lairage, and 4) arched back righting reflex with the head bent back while hanging on the rail. The following signs are NOT signs of return to sensibility: nystagmus (rapidly vibrating eye) and gasping like a fish out of water. An eye with nystagmus movements moves much more quickly than natural blinking. Nystagmus and gasping are not scored as return to sensibility after electric stunning. After captive bolt stunning nystagmus and grasping must be absent. The eye should open into a wide blank stare and not be rotated. After captive bolt stunning, the corneal reflex must be absent. See chart in 2010 AMS guidelines.


Well written comments are essential. On all core criteria that do not pass, the auditor should write a description of what happened. Below are examples of poor descriptions and examples of complete, good descriptions. Good descriptions are essential for evaluating problems and determining the severity of a problem. Auditors should also write a description of other welfare problems that they observe that are not one of the core criteria. Really good practices should also be described.

Insensibility Failure Description Examples

Poor Description Example -Animal not properly stunned and rendered insensible.

Good Description Examples -

A. The animal had spontaneous natural blinking without touching the eye.
B. The animal was squealing after stunning.
C. The animal had a corneal reflex and the eyelid moved when the cornea was touched with the tip of a pen.
D. The animal was walking around after stunning.
E. The animal had a full righting reflex while hanging on the shackle and it oriented and turned its head towards people walking by it.

Stunning Failure Description Examples

Poor Description Example - Bad stunning.

Good Description Examples -

A. The operator placed the stunner in the correct position, but the dirty corroded captive bolt stunner did not have sufficient power to stun the animal.
B. The electric stunner wand was placed on the pig’s shoulder instead of in the correct location behind the pig’s ear.
C. The operator got nervous and failed on stunning while I was standing on the stunner platform. He was able to pass the audit when I stood in a location where he could not see me and thought I was gone.

Vocalization Failure Description Examples

Poor Description Example – There was a lot of vocalization.

Good Description Examples -

A. Cattle vocalized in response to electric prod use when they balked and refused to enter the stun box.
B. Cattle vocalized in the stun box when they became agitated due to repeated rapid slips.
C. Pigs squealed in the restrainer when they contacted a broken sharp metal edge.
D. Cattle vocalized when the head holder was applied just prior to religious slaughter.
E. Cattle made little soft moos in the lead up chute that were not associated with an aversive event such as electric prod use or repeated rapid slips.

Electric Prod Use Failure Description Examples

Poor Description Example – There was overuse of the electric prod.

Good Description Examples -

A. The animals constantly backed up and refused to move forward so they had to be moved with and electric prod.
B. The crowd pen was filled completely full and the pigs were rearing and squealing. The electric prod was used to move them into the single file chute.
C. The employees were screaming and yelling and agitated animals kept turning back.
D. An untrained employee used the electric prod as his primary driving tool. He had no alternative aid such as a paddle or flag.

Falling Failure Description Examples

Poor Description Example - Many animals slipped.

Good Description Examples -

A. The animal stumbled and went down on its knee in the stun box.
B. Three animals slid about three feet in the truck unloading area. Even though this is not a failure it is a deficiency that should be corrected.

These are just examples of good comments. They can serve as a guide on how to write clean descriptive comments. There are many other problems that can cause failure and auditors should write comments to describe them.

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