Based on 20 years of personal experience, this author describes three steps for improving the handling of hogs and cattle: selecting animals with a calm temperament, correcting facility problems that impede livestock movement, and training handlers.
Temple Grandin, PhD
Department of Animal Sciences
ColIege of Agricultural Sciences
Colorado State University
Fort Collins, Colorado 80523
To solve animal handling problems, veterinarians must determine if the difficulties arise from one or more of the following factors:During the past few years, I have observed an increasing number of handling problems caused by nervous, flighty, excitable hogs and cattle. Both producers and seed stock breeders should be encouraged to select animals with a calm temperament. Animals balking and refusing to move through a chute or other facility can also be caused by a wide array of facility defects, ranging from major mistakes in design to easily corrected problems such as inadequate lighting. The most common problems related to personnel are rough handling, excessive prodding, and overcrowding of animals in a crowd pen. Cattle and hogs remember bad experiences, and animals that have been handled roughly become more difficult to handle in the future.(1,2) Successful identification and correction of factors that contribute to animal handling problems can help produce better quality meat and provide a safer environment for both the animals and their handlers. Agitation and excitement during handling shortly before slaughter can increase the occurrence of meat-quality defects (pale soft exudative pork and dark cutting in beef). Both of these conditions reduce the quality and value of the meat.
- an animal temperament problem
- a facility problem, or
- a personnel problem.
Choosing less excitable genetic lines
One factor that contributes to handling problems is an excitable animal temperament. Hogs from excitable genetic lines are more difficult to drive through chutes because they tend to bunch together.(3) Both hogs and cattle from excitable genetic lines are more likely to balk or back up when being moved through chutes or into a restraint device. Excitable animals appear to be more vigilant and wary of novelty (such as sounds they have not heard before) than are animals with a calmer temperament. I have observed excitable animals balk at small distractions, such as a shadow or a puddle, that a calmer animal would ignore. Cattle with an excitable temperament are more likely to become agitated and injure themselves when they experience something new such as handling at an auction. Excitable cattle that have been handled gently may be quiet and calm when they are in familiar surroundings, but may become highly agitated at an auction or feedlot.
Nervous, excitable temperament appears to cause handling problems that are somewhat different from the agitated behavior caused by experiences with rough handling. When excitable cattle are restrained, their behavior appears to be similar to that of a frenzied horse that has caught its leg in a fence. Animals with an excitable temperament are more likely to vocalize or injure themselves during handling. I recently observed a group of feedlot heifers that constantly bellowed while standing in the crowd pen at a packing plant. These cattle were very nervous, and they jumped and reared much more often than the other cattle processed that day. These heifers also had a masculine appearance, probably due to the excessive use of androgenic growth implants. On a nother day, I observed a second group of European-continental-cross heifers that constantly bellowed and kicked at handlers. Three animals arrived at the plant with severe hoof injuries. The cattle appeared otherwise normal. The injuries seemed to have occurred when the animals panicked after their feet had been caught in a truck ramp at the feedlot.
The increasing occurrence of flighty, excitable livestock coincides with the drive to produce leaner pork and beef. In my opinion, indiscriminant selection for rapid growth and leanness tends to produce animals with a more excitable temperament. My observations at packing plants indicate that increased excitability is causing serious handling problems. Some groups of hogs or cattle are easy to drive and others constantly balk and show signs of agitation. This not only can reduce the quality of the meat but causes an animal welfare problem because excitable animals that refuse to move through a handling facility are more likely to be handled in an abusive manner by frustrated handlers. Practical experience has shown that flighty, excitable animals are more likely to have meat quality defects (e.g. pale soft exudative pork or dark cutting in beef).
In cattle, the most serious temperament problems tend to occur in European continental breeds. Cattle from some genetic lines of these breeds are excitable. The history of the continental breeds may explain why the British breeds are less likely to go in to a frenzy in a squeeze chute. I speculate that breeds from countries such as France and Italy have more severe temperament problems than breeds from England because they have not been reared under extensive conditions on range land where they have little contact with people. For centuries, French beef cattle have been halter broken, milked, and tamed. Today in French packing plants, cattle are held in halter "tie up" stalls similar to a livestock show. When cattle are completely tamed and acclimated to people, milking machines, and vehicles, excitable temperament traits may be masked. Therefore, producers have never had to cull animals for temperament problems. British producers, on the other hand, have reared cattle semi-extensively on pasture. Their animals were seldom halter broken. Animals from excitable genetic lines would have been culled because handling them in primitive handling facilities is difficult and dangerous.
Practitioners should educate producers and breeders on choosing lean animals with calm temperaments. An easy method of scoring the temperament of breeding stock is to rank animals by temperament while each is held in a squeeze chute or a scale. Each animal needs to be rated individually because temperament differences are less apparent when animals are in a group. A simple ranking system is as follows:
It is also essential that each animal's temperament be evaluated more than once. In one study, 9% of 53 bulls received a 4 or 5 ranking during four different handling sessions, and about 50% of the bulls were always calm, receiving a ranking of 1 or 2 each time.(4) The rest of the animals had mixed ratings. Similar results were obtained when 102 steers were rated. Six percent of the steers became agitated every time they were handled, and 64% were always calm. This is why culling decisions should be base d on two or three evaluations. Animals that consistently exhibit bad dispositions when handled are the ones that need to be culled. Culling based on one evaluation may remove a good animal that became excited only because another animal nearby was excited . Excitement tends to spread through a group of cattle or hogs. One excited animal can excite other usually calm animals.
Troubleshooting Problems with Facilities
The first step in troubleshooting facility problems is to distinguish between major design mistakes and easily corrected faults. The most serious layout mistake is deadending a single file chute that leads up to a squeeze chute. The single file chute must not be bent sharply at the junction between the chute and the crowd pen. A facility with a deadended chute works very poorly because animals will refuse to enter the chute. To induce them to enter, cattle and hogs standing in a crowd pen must be able to see at least two body lengths ahead in a single file chute. For cattle, a curved chute is more efficient because it prevents them from seeing people up ahead. Figure 1 shows a curved handling facility I designed.
A curved processing facility designed by the author for handling feedlot cattle. To facilitate the movement of cattle, the single file chute, the crowd pen, and the curved approach alley all have solid sides. Curves improve cattle flow because the a nimals cannot see people standing by the squeeze chute. The chute must be designed so that cattle standing in the crowd pen can see two body lengths into the chute entrance.
Hogs will refuse to leave their building during truck loading when it is either cold or very bright outside. Enclosing the loading facilities usually will improve the hogs' movement. Animals also often refuse to enter a dark place. when single file chutes are used to direct cattle to a squeeze chute, a wall of the building should never fall at the junction between the crowd pen and the single file chute because the wall makes the entrance look dark. Cattle move more readily if they are lined up in the single file chute before they pass through an entrance in the wall of a building. Therefore, the single file chute should extend two or more body lengths from a wall. Both cattle and hogs have wide angle vision.(5) Many chutes and loading ramps can be greatly improved by adding solid sides to block the animal's peripheral vision. Solid sides on single file chutes, crowd pens, and loading ramps will facilitate animal movement (Figure 1).2 Crowd gates on crowd pens should also be solid to keep animals from trying to turn back.
Another common mistake is building chutes that are too wide. It is impossible to move animals quietly through a chute if they become jammed side by side. Single file chutes for market-weight hogs should be 41 cm wide, and cattle chutes should be 66 to 71 cm wide for cows and 76 cm wide for market weight feedlot cattle. Single-file chutes should be sized so that the largest animal has only 1 or 2 cm of clearance on each side.
Non slip flooring is absolutely essential for safe, humane livestock handling. It is impossible to handle animals calmly and quietly if they are constantly slipping or falling down. Falling on scales and in front of the squeeze chute can be prevented by installing a floor grating constructed from 1-in. steel rods placed on 12-in. centers.
I have learned of an increasing number of injuries to cattle caused by headgates. The problem may partially be due to more excitable cattle, but many of these injuries are caused by failure to slow the animal down in the squeeze chute before it hits the headgate. Excessive use of electric prods also contributes to injuries because excited cattle hit the headgate too hard. Flighty cattle remain calmer if the standard open barred sides of a squeeze chute are covered. Simple, solid, drop down panels can be constructed to allow access to the animal.
For hydraulic squeeze chutes, the pressure relief valve must be set properly to prevent excessive pressure from injuring the animals. Some examples of injuries caused by excessive pressure are broken ribs, a ruptured diaphragm, or a fractured pelvis. when the squeeze control lever is pressed all the way down, the relief valve must automatically bypass to the hydraulic reservoir to prevent excessive pressure on the animal. Animals must be held snugly to provide the feeling of being held, but excessive pressure causes pain and animals will fight restraint. If the squeeze chute is too tight, the pressure should be reduced slowly; a sudden or jerky motion causes excitement, but a slow, steady motion is calming.
Simple Improvements in Facilities
Some excitability problems in hogs are caused by a lack of environmental stimulation in indoor growing and finishing buildings. Playing a radio in the finishing building can help prevent an excessive startle reaction to a sudden noise, such as a door slamming shut. Providing finishing hogs with hanging rubber hose toys to chew and ensuring weekly contact with people in their pens will produce calmer animals that are easier to handle. The animals do distinguish between interacting with people in their pens and seeing people in the aisles, so it is important to have personnel actually enter each pen. If people remain only in the aisles, the animals are more likely to be fearful when a person enters their pen for truck loading.
Distractions that appear to be insignificant, such as a wiggling chain in a chute, and lighting mistakes, such as a chute entrance that looks like a black cave to the animal, can ruin the efficiency of the best chutes and crowd pens. Simple changes in lighting can improve animal movement. At night, lamps can be used to attract animals to trucks, and, in indoor facilities, chutes must be illuminated so animals can see where they are going. Both cattle and hogs tend to move from darker places to brighter areas.(2,6) To attract the animals, the lamps must be aimed toward the place the animals are entering. A good example is using a spotlight to encourage animals to move into a chute. The lamp must not shine into the eyes of approaching animals because glaring, blinding light impedes movement.
Both cattle and hogs will balk if they see a sparkling reflection in a puddle or a moving reflection on a sheet of metal. To locate these problems, someone must get into the empty chute and see what the animal is seeing. Moving a lamp away from the center line of a chute can eliminate a reflection on a wet floor. Any object on a fence or in a chute that appears novel also causes balking. A piece of paper lying in an alley causes both cattle and hogs to stop. A hat or coat hanging on a fence causes balkin g. I have seen cattle balk at a small chain hanging down in a single-file chute. In one location, the leader of an approaching group of cattle stopped to watch a small, jiggling chain. In another facility, hogs balked when they had to pass by a jiggling gate. Some of these distractions are subtle and require careful observation for people to detect them. To determine if small distractions are causing the balking, the animals have to be calm. It is almost impossible to determine the cause of balking when c attle or hogs are excited. Calm animals will stop and look directly at what is distracting them.
Both cattle and hogs are sensitive to changes in the color and texture of floors and fences. Animals tend to balk when moving between areas with different types of fences. Painting facilities a single color improves movement. Most colors work well, but light colors should be used in warmer areas of the country to keep the facility cooler. Contrary to popular belief, cattle and hogs do see color.(7,) Drain grates and metal plates on the floor also cause balking when animals are driven over them. In beef facilities, drains should be located outside of main drive alleys, chutes, and crowd pens. A dairy cow that walks over a grate every day learns to ignore it, but an animal that has just arrived at the dairy will balk at the grate for several days. In swine confinement facilities, hogs will balk at white plastic strips used as door thresholds. Figure 2 shows a plastic threshold that hogs refused to walk over.
Hogs may refuse to walk over this plastic strip on the floor. Animals will move more easily if the same type of flooring is used throughout a facility.
Grower, finishing, or nursery pigs that have never walked on concrete floors often refuse to move on such a surface. Pigs raised on metal mesh or plastic floors walk more readily on concrete if they are allowed to explore a concrete floor for 30 to 60 minutes before driving or other handling is attempted.
Animals may also refuse to move if they can see people ahead. Practitioners need to look up the chutes to determine if the animals can see other people ahead. Installing shields to prevent animals from seeing people farther ahead often facilitates movement. Gates can also be rigged with remote controls so that they can be opened by a handler standing behind the cattle.
Noise reduction in facilities
High-frequency sounds or loud intermittent noises are likely to cause animals to balk Although no studies are available on sound sensitivity in hogs, cattle and sheep are more sensitive to high-pitched sounds than people are.(9,10) The high-pitched whine from a hydraulic pump on a squeeze chute may increase balking in cattle. The pump and motor should be moved off the squeeze chute or a low-noise pump and motor must be purchased. At packing plants, I have seen cattle balk at a high-pitched noise, such as the whine of undersized hydraulic plumbing, but ignore a low-frequency sound, such as the rumbling of a chain conveyor. Cattle voluntarily entered chutes near equipment that made a low-frequency rumbling. The sound of metal clanging and banging causes a startle reaction, but I have seen an even greater startle reaction to air exhausts that hissed. Hissing air exhausts should be piped outside or quieted with mufflers that can be purchased from an industrial supplier.
Perfecting handling procedures
Quiet, calm handling of animals is impossible in facilities where animals constantly balk or stop. However, once problems with the facilities are fixed, the next step is to perfect calm, quiet handling methods. Handlers need to be trained in the basic principles of livestock behavior. The most important principles relate to the animal's flight zone and point of balance. The point of balance is located at the animal's shoulder. To make an animal move forward, the handler must be positioned behind the point of balance.(11,12) To make an animal move backward, the handler must stand in front of the point of balance. Handlers often make the mistake of standing in front of an animal while attempting to move it forward. Handlers must also learn to position thems elves on the edge of the animal's flight zone. The flight zone is the animal's personal space, and its size is determined by the wildness or tameness of the animal. when a person enters the flight zone, the animal will move away. The size of the flight zone varies from 0 m for tame, halter-broken cattle, to 2 to 5 m for feedlot cattle, to 5 to 20 m for range cattle. Cattle that have been treated roughly have a larger flight zone. The animal's experiences have a tremendous effect on its current behavior and response to stress.(1,13)
One of the most common handling mistakes is placing too many animals in a crowd pen. A crowd pen should never be more than three quarters full. Livestock will move into a chute more efficiently if handlers wait until the chute is half empty before bringing another group into the crowd pen. This provides sufficient chute space so that several animals can follow a leader into it.
Overuse of electric prods is another frequent handling problem. The prod should be used only if an animal refuses to enter a squeeze chute or truck. Cattle must never be prodded when there is no place to go. Electric prods should never be used on breedin g swine, and should be used sparingly when loading market hogs. The use of electric prods on breeding swine may cause them to fear people.
Australian research has shown that sows that are fearful of people will farrow fewer piglets.(13) Cows will learn to move promptly to avoid electric prodding, and may even learn to move when they simply hear the buzz of an electric prod.
If tail twisting is used to move cattle, the handler must release the tail when the animal moves forward. This rewards the animal for moving. The next time, the animal will move when the handler touches its tail. Many handlers make the mistake of continuously twisting the tail.
Both cattle and hogs can be moved and turned in a crowd pen by using a stick with either plastic streamers or a plastic garbage bag tied on the end (Figure 3). The plastic is used to block the animal's vision on one side and make it turn. Cattle can be easily turned and guided with the plastic streamers.
A stick with a plastic streamer on the end is a useful tool for moving cattle out of a crowd pen and into the single file chute. The streamer is waved beside an animal's head to turn it.
I have observed that many handling problems related to personnel have resulted from poor management or a lack of employee training. On many large operations, I have seen handling practices either improve or become rougher when a new manager is hired. From 20 years of experience, I have concluded that management's attitude is the single most important determinant of how animals are treated. The best facilities in the world are worthless unless they are managed well.
In conclusion, the three steps to improving livestock handling are selecting animals with a calm temperament, correcting problems in the facility that impede livestock movement, and training handlers.
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