TINY DETAILS THAT SCARE FARM ANIMALS
Here’s the checklist I give plant owners when their cattle or hogs are refusing to walk through an alley or a chute:
1. SPARKLING REFLECTIONS ON PUDDLES
I figured this out at a plant where the pigs were constantly backing up in the alley, so the employees were using electric prods to keep them moving forward. The plant was failing its animal welfare audit, because workers were supposed to be using the prods on no more than 25 percent of the pigs, and they were using them on every single animal. Normally a pig has no problem walking through a chute, but in this plant every single pig was stopping and backing up.
I got down on my hands and knees and went through the chute the same way the pigs did. The managers probably thought I looked crazy, but that’s the only way you can do it. You have to get to the same level as the animals, and look at things from the same angle of vision.
Sure enough, as soon as I got down on all fours I could see that there were lots of tiny, bright reflections glancing off the wet floor. Plant floors are always wet, because they’re always being hosed down to keep them clean. Nobody could have seen those reflections even if they did know what to look for, because the humans’ eyes weren’t on the same level as the pigs’.
Once we knew what the problem was I got back down on my hands and knees again, and while I was pretending I was a pig the employees moved the big hanging lights overhead with a stick until each little reflection was gone. And that was that. Once the reflections were gone the pigs walked right up the chute, and the plant passed its audit.
2. REFLECTIONS ON SMOOTH METAL
I first saw this with cattle walking up a single-file chute that was made of shiny stainless steel. Every time the sides jiggled the shiny reflections from the lights would vibrate and oscillate, and the cattle would stop. In that plant all we had to do was move the lights, but in another plant with the same problem, we had to bolt the sides down so they couldn’t move at all.
A still reflection is always less of a problem for an animal than a moving one, although any bright reflecting surface can scare an animal. A lot of times we have to move the lights and bolt down the metal sides. A number of things can cause reflections to move: machine vibrations, or cattle banging up against the metal, or water running off a ramp into the water that’s already on the floor, making the reflections on the surface jump and move like a sparkling brook.
3. CHAINS THAT JIGGLE
I learned about jiggling chains in a big beef plant in Colorado that had a chain hanging down at the entrance of the chute. The chain was part of a gate latch, and it wasn’t very long; maybe only one foot, and swinging back and forth three inches each way. But that was enough. The cattle would come around a curve, take one look at that chain, then stop and stare at it with their heads swinging back and forth in rhythm with the chain. You’d think that would be obvious to the employees, but it wasn’t. The humans just didn’t see it, even though the cows’ heads were going back and forth in rhythm to the swinging of the chain. I’m not sure the employees even noticed that the cows’ heads were moving; forget the chain. The employees were just using more force, zapping them with cattle prods, screaming and yelling and so on, to try to get the cattle moving.
4. METAL CLANGING OR BANGING
This one’s universal. You see it everywhere in feed yards and plants—metal gates, sliding doors, squeeze chutes—everywhere. People in the industry call it clatter, and clatter is something you always have with metal equipment. I recommend plastic tracks for sliding doors, so you don’t have metal sliding against metal, and now a company named Silencer makes an extra-quiet squeeze chute that’s good, too.
5. HIGH-PITCHED NOISE
Examples: backup alarms on trucks and high-pitched motor whining.
I remember my first experience with this at a big beef plant in Nebraska where they’d just put in one of my cattle-handling systems. They used a hydraulic system that gave off a high-pitched whining noise, and the noise would get the cattle all agitated so my system didn’t work. We changed the plumbing to eliminate the noise and the cattle became a lot calmer.
6. AIR HISSING
Another one you see everywhere. The problem with high-pitched sounds like hissing air and hydraulic squeals is that they’re too close to distress calls, which are almost always high-pitched. High-pitched sounds are one of the few things humans will usually notice, especially if they’re intermittent, because we inherited a built-in alarm system from our animal ancestors that’s still working. That’s why humans choose high-pitched intermittent sounds when they want to make sure they get people’s attention. Police cars, ambulances, garbage truck backup beeps—it’s almost always a high-pitched intermittent sound. The people who design these systems instinctively go for the kind of sound animals use to signal danger.
7. AIR DRAFTS BLOWING ON APPROACHING ANIMALS
I don’t know why cattle don’t like this; I just know they don’t. Whenever cattle are out in a big storm, they’ll turn their bottoms to the wind. I also hear stories about dogs hating to have air blown into their faces or their ears. This seems to be something kids like to do to dogs, so I’ve heard quite a few of these stories.
8. CLOTHING HUNG ON FENCE
I say “clothing” because the problem almost always is clothing, but anything hanging on a fence can scare animals. Usually what happens is that people get hot, take off their jackets and shirts, and hang them on the fence. Sometimes people will drape towels or rags on the fence, which is just as bad. Once I went to a ranch that had a wiggling plastic jug wired to the fence and that was causing problems.
The worst is when you have yellow clothing hanging on fences. I first saw this happen at a plant in Colorado. It’s the same problem as the bright yellow ladder against the gray wall I mentioned a while back. No cow will walk toward a sudden patch of bright yellow color.
9. PIECE OF PLASTIC THAT IS MOVING
Anything moving is a problem for animals, but usually I find the problem will be a piece of plastic. That’s because people in the industry put plastic all over everything. They’ll tape it over a window to keep the cold air out, or wrap it around a pipe because the pipe is dripping, and it always vibrates and jiggles. Plastic just has a way of getting stuck all over the place, especially now, with the new food safety rules. Employees pull plastic off big rolls and make raincoats out of it, or aprons and leg guards; the plants let the employees make anything they want out of the stuff. Then it ends up getting caught on something where it jiggles and scares the animals. Paper towels will also scare pigs and cattle if the wind is blowing it. I had a paper towel problem at five or six different places.
10. SLOW FAN BLADE MOVEMENT
I’ve seen this in several different places. Animals don’t have a problem with an electric fan that’s turned on the way autistic children do. A lot of autistic children are riveted by the motion of the blades, or by just about anything that’s spinning fast. I don’t know why this happens, but I think they may be seeing the flicker of the fan blades even at very high speeds. I’ve met a number of dyslexic people who can see the flicker, so I assume many autistic people see it, too. Dyslexics who can see the blade flicker say it’s horribly distracting and fatiguing.
The motion is part of the attraction, too. I don’t get hooked on fans myself, but I do get stuck on those geometric screen savers a lot of computers have. I can’t stop looking at them, literally, so if I’m in an office where there’s a geometric screen saver either I have to sit with my back to the screen, or ask the owner to turn it off.
With fans, what drives an animal crazy is when the fan is turned off, but the blades are rotating slowly in the breeze. You have to put up big pieces of plywood or metal so the animals can’t see the fan. Otherwise, forget it. They’re going to balk. I went to one ranch where they had a windmill that was messing up the animals. On windy days the animals wouldn’t move.
11. SEEING PEOPLE MOVING UP AHEAD
; Another case for plywood. I mentioned this one earlier. Cattle are eighteen months old when they’re slaughtered, and pigs are only five months old, so it doesn’t pay to train them to lead. They’re not like horses who’ve been trained to accept a halter and a lead rope and walk calmly alongside a human being.
12. SMALL OBJECT ON THE FLOOR
Example: a white Styrofoam coffee cup on a muddy brown floor.
I had a bad experience with this one time when I was up on a catwalk above a cattle chute. An employee at the plant had been storing his white plastic water bottle on the catwalk, and I accidentally kicked it off. The minute it hit the ground, I said a bad word. It landed right at the entrance to the chute, where I knew it was going to cause a problem, and it did. That little plastic water bottle lying harmlessly on the ground was as big a barrier for those 1,200-pound cows as if I’d dropped a big pile of boulders there.
We had to shut the whole line down, because no animal would walk over it, and it was too dangerous for anyone to go in there and try to pick it up. A crowd pen is a small space, and there were fifteen big animals in it, none of them trained to lead; a human going inside the pen could have been crushed. So the employees had to stand outside and run at the cattle and chase them until finally one of the cows stepped on the bottle and crushed it into the manure so that it turned brown, not white. Then the cattle were fine. They all stepped over it and went on into the alley. That part of the line was shut down for fifteen minutes, and the plant as a whole lost five minutes. At $200 a minute that was a $1,000 delay.
13. CHANGES IN FLOORING AND TEXTURE
Example: cattle or pigs moving from a metal floor to a concrete floor or vice versa.
The problem is contrast.
14. DRAIN GRATE ON THE FLOOR
Same problem again: contrast. The drain grate looks too different from the floor.
15. SUDDEN CHANGES IN THE COLOR OF EQUIPMENT
High-contrast color changes are the worst. You can’t have the gates painted one color and the pens painted another. I’ve also seen problems with gray-painted alleys leading up to shiny metal equipment.
16. CHUTE ENTRANCE TOO DARK
Another contrast issue—going from light to dark.
17. BRIGHT LIGHT SUCH AS BLINDING SUN
If you have the sun coming up over the top of a building just as the cattle are approaching there is nothing you can do. It is a hell of a problem and there isn’t any way to fix it except maybe extend the roof out over the yards. Otherwise you just have to suffer through it.
18. ONE-WAY OR ANTI-BACKUP GATES
These are two different terms for the same thing. Anti-backup gates don’t look like the normal gates the cattle are used to seeing on a ranch. Anti-backup gates hang down from overhead instead of being attached on one side, and basically look like a cow- or pig-sized dog door in a house. Plants install one-way gates in single-file alleys to keep the cattle from backing up into the long line of animals behind them. The pig or cow pushes through the gate—the same way a dog pushes through a dog door—and the gate falls down behind each pig or cow after it walks through. It’s not flexible like a dog door, so you can’t push it backward, only forward.
The animals hate having to push through the gate. That’s the problem, the going-through. The anti-backup gates bother the animals so much I don’t like to use them. I work with the cattle gently enough that they’re all happy to keep walking forward, and I can just tie the doors up out of the way, where the cattle don’t see them and don’t have to deal with them.
You could make up the same kind of list for any animal, although it would be different for each one. Bats have sonar and dogs don’t, so the list of common distractions for bats is going to have some sonar distracters on it, while the dog’s distracter list won’t. But any list of common distractions for an animal would be highly, highly detailed, exactly like this one.
THE DIFFERENCE BETWEEN ANIMAL VISION AND HUMAN VISION
Although I created this list for cattle and hogs, you can use this list to predict trouble spots for any other animal if you think about what these eighteen distracters have in common.
First of all, fourteen out of the eighteen distracters are visual, and I wouldn’t be surprised to find a ratio like that for most animals. But to predict what kind of visual object will distract or frighten an animal, you have to know more about what animal vision is like.
It’s pretty different from ours. For instance, you always hear that dogs “don’t see well,” which is true as far as it goes. Dogs don’t have very good visual acuity, which is the ability to see the tiny details of what you’re looking at clearly and crisply. People with 20/20 vision have excellent visual acuity, and a lot of animals don’t. That means that most animals aren’t going to be frightened by tiny objects, simply because they can’t see them well.
A typical dog has a visual acuity of 20/75, which means that a dog has to stand twenty feet away to clearly see an object a person with normal vision sees well standing seventy-five feet away. The dog has to get much closer to the object than we do. This isn’t due to nearsightedness but to the fact that dogs have fewer cones in their retinas than people do. Everyone probably remembers from biology class that cones handle color and daytime vision, and rods handle nighttime vision. Basically dogs have traded good visual acuity for good nighttime vision. A dog doesn’t see any objects as sharply as a person does, including an object that’s right under his nose. That’s why it’s so hard for dogs to see a piece of kibble you’ve dropped on the floor for them to eat. If they didn’t watch it fall, most dogs can’t see it lying on a mottle-colored tile floor (though some can).
There’s also a lot of variation in visual acuity among the different breeds of dogs, as well as among individuals of a breed. One study found that 53 percent of German shepherds and 64 percent of Rottweilers were nearsighted. You might wonder whether being nearsighted matters to a dog since everything it sees is fuzzy to start out with, but tests show that it does. A nearsighted dog has much worse visual acuity than a normal-sighted dog. Interestingly, although German shepherds tend to be nearsighted, only 15 percent of the Shepherds in a demanding program for guide dogs were myopic.2 Probably the nearsighted dogs were flunking out of the program without the trainers’ knowing why.
Another huge difference between animals and people is that most animals have panoramic vision. The eyes of prey animals like horses, sheep, and cows are set so far apart that they can literally see behind their heads. That’s why some hansom cab horses wear blinkers; they can see everything going on behind them, and they get distracted. Most racehorses don’t wear blinkers for the same reason: their trainers want them to know exactly where the horses behind them are, and how fast they’re moving.
Prey animals don’t have perfect 360-degree vision, although they come close. There’s one small blind spot directly behind a cow or horse that you have to be careful not to sneak up to. The animal can’t tell what you are, and he might get scared and lash out and kick you. Prey animals also have a small blind spot directly in front of their heads because their eyes are set so far to the sides.
Even though their eyes are so far apart, prey animals do have depth perception, though it seems to be different from ours. We use binocular vision, which means each eye is seeing the same thing from a slightly different angle. When our brains combine the angles, we get our sense of depth.
Prey animals’ eyes are so far apart that a lot of researchers have assumed their left eye was seeing something completely different from the right eye, so they couldn’t have binocular vision. But they’ve tested this in sheep, and sheep do have at least some binocular vision. We know this because sheep can see the cliff in visual cliff experiments. In the original visual cliff studies the experimenters put a baby on top of a table covered in a sheet of glass thick enough to crawl on. Directly underneath the glass there was a checkered surface that, midway across the table, suddenly dropped off way below the glass surface. It was a visual cliff, not a re
al one, so the baby couldn’t actually fall over the edge if he crawled out over the drop-off. Very young babies will refuse to crawl over the cliff even if their mothers stand on the opposite side of the table and call them. They can see the cliff, and they instinctively know it’s dangerous. It turns out that sheep won’t walk over the cliff, either, which means they have to be seeing the difference in depth. (On the other hand, sheep don’t appear to have depth perception while they’re moving, only when they stand still.)
You’ve probably seen bulls in bullfights lower their heads before they charge the matador. Border collies do the exact same thing when they’re herding sheep. They lower their heads below their shoulders and stare at the sheep. They do this because their retinas are different from ours. The human retina has a fovea, which is a round spot in the back of the eye where you get your best vision. Domestic animals and fast animals who live on the open plains like antelopes and gazelles have a visual streak instead of a fovea. The visual streak is a straight line across the back of the retina. When you see an animal lower its head to look at something, it’s probably getting the image lined up on its visual streak. Most experts think the streak helps animals scan the horizon.
Researchers have also found that of the meat-eating animals that have been tested so far, the two fastest animals—the cheetah and the greyhound—also have the most highly developed visual streaks. Their visual streaks are dense with photoreceptors, giving them extra-acute vision. To test visual acuity you can use a bar code design. The more acute your vision, the tinier a bar code you can look at, from a greater distance, and still see the stripes as separate rather than as a gray square. Animals with super-acute vision can also see separate grains of sand on the beach.
Animals in Translation Page 5