The Art of Handling Pigs
A good stockmanship can reduce pigs’ fear levels and improve production. Pigs naturally resent handlers getting into their personal space. Handlers should learn to think like a pig and use a pig’s natural “flight zone” (Figure A) – the animal’s instinctive escape route– to help herd them. If a handler enters this circular zone, the pig will step away to maintain the circle’s size.
The direction the pigs will move depends on where handlers position themselves in relation to the circle’s “point of balance.” If handlers step behind the point of balance, pigs will move forward; if they step in front of them, animals will turn back. In effect, handlers who try to move animals by standing behind them in the animal’s blind spot only slow down the process. Pigs will turn to face the person entering their space rather than move forward.
Handlers should train their pigs to respond by using these flight zones. They should apply pressure by invading the animals flight zone then provide relief by stepping out once the animal has responded correctly.
FIGURE A
Pigs Need Space
Crowding livestock during transport is a costly practice. It may reduce transportation costs on a per animal basis but it is not worth the risk in terms of animal suffering and death loss risks. During the winter, overcrowding can result in frostbite damage; during the summer, overcrowded pigs may die from heat stress. Both problems are avoidable.
On short trips – those less than four hours – pigs may prefer to stand. On longer trips they will lie down. Groups of recumbent hogs will require more floor space so loading densities should be reduced for long trips.
There is a limit to the number of pigs you can squeeze into a given space, even without considering animal comfort. If loaded at 4 ft2 per 250 lb. hog, market-size animals will be snug when standing. Dividers should be used so no more than 30 market hogs are held in any section of the trailer during transport. If the trip will take longer than four hours and the animals are likely to lie down, space should be increased to about 4.8 ft2 per 250 lb. hog. Appendix A has charts which list the maximum recommended loading densities for hogs of various sizes. Hogs tire from standing on long trips and will compete for floor space if it’s not available. That kind of competition generates heat (and noise) and puts increased stress on the animals.
Pigs cannot sweat to cool them- selves. Excess heat will move by convection from the skin, but pigs will pant through their mouth when overheated. Overcrowding, as well as conditions such as atrophic rhinitis, can reduce an animal’s ability to cool itself by panting. Fighting for floor space and excessive panting contribute to more body heat being generated. These stresses increase the problems associated with summer confinement conditions.
There is a misconception that during cold weather you should pack more pigs into the load to generate heat. This is wrong. In fact, many truckers decrease the number of hogs in the load during the winter and add more bedding.
In overloaded trucks, pigs are unable to reposition themselves if they’re not comfortable. They can’t move away from drafts and cold spots. That leads to increased frostbite risk. Crowded hogs will also be pressed against the sides of metal trailers and will be more susceptible to frost- bite. Metal compartments should be lined with wood to prevent contact frostbite.
Remember that pigs of substantially different weights and ages must be penned separately during transportation. Cull sows over 375 lbs. must not be mixed up with market hogs. Sick or weak pigs should also be penned separately. Avoid transporting pregnant sows within 6 weeks of expected farrowing or sows with a suckling litter.
Loading density standards
At lower space allowances, pigs encounter higher ambient temperatures, decreased ventilation and air quality, as well as insufficient space to lie down in transit. At the other end of the spectrum, increased space allowance reduces vehicle temperature and increases ventilation, but it can also increase the incidence of fighting and aggression in transit.
Overcrowding can result in increased mortality rates, food safety concerns, and reduced meat quality (primarily the incidence of pale-soft-exudative (PSE) meat). Space allowances above 0.45-0.5 m2/100 kg pig can increase skin damage and the incidence of dark-firm-dry (DFD) meat.
Proper pig density can offset the effects of high temperatures by providing adequate ventilation through vehicle vents, regulating heat production within the vehicle, and providing animals with adequate space to accommodate their size, behavior and positions during transport.
The effect of extremely hot and extremely cold conditions during transport and its effect on loading density also needs to be studied in greater detail, This is of particular importance in Canada due to the extremes in temperature which are experienced throughout the country and over the course of a year.
During Transit
Farmers or handlers should check their pigs periodically during transit – once within the first hour after loading and every two hours after that. This is especially important in changeable weather. During the check stops, drivers should examine each load compartment and monitor all thermometers and heat sensors. The legislated maximum transport time for market hogs is 36 hours and the minimum time between feed, water and rest times is 5 hours.
Still, there’s no guarantee things still won’t go wrong during transit and handling. When they do, calming down the pigs is the priority. Stopping to give both pigs and handlers time to settle down is a much better idea than speeding up to hasten delivery.
In transit, some pigs will vomit, a condition some people consider a form of “motion sickness.” Holding back some feed prior to transporting will reduce this risk.
When it comes to detecting cold spots in a trailer, the dumbest pig is smarter than the wisest trucker. Pigs huddling and attempting to root in straw bedding during transit is a good indication the animals are cold and under stress. Using lots of bedding and giving the animals enough room to reposition themselves for maximum comfort will eliminate most minor transportation problems.
When the weather changes significantly, trailers must be adjusted to protect the animals. On long distance shipments, only trailers in which ventilation can be adjusted from outside should be used. Many truckers have installed misting systems in their hog liners for hot weather transport.
Temperature sensors or regular thermometers should be installed in every load compartment – located so they can be easily read by the driver at check stops.
Farmers who follow these guidelines can make their pigs’ journey from farm to market a more comfortable one. There should be enough dividers available to limit the number of pigs in any one section of the transport vehicle to 30. Load compartments should be built so one or two pigs can be penned separately to isolate them from the rest of the load if necessary. Where possible, pen mates should be shipped together in the same compartment to reduce fighting and accompanying injury risks.
Travel duration
The scientific literature has yet to reach a consensus on maximum transport times or the precise impact of rest periods during transport, both of which can affect meat, points out Dr. Schaefer. In fact, there is one school of thought that says short journeys may be more detrimental – for instance higher mortality rates due to animals being unable to adjust to transport stress – than for longer ones and every effort to attenuate such stress during short transport journeys should be made.
The loading and unloading of animals is the most stressful component of livestock transport. Unloading animals for rest periods mid-transport may increase the stress experienced by transported animals. Research on loading and unloading during long distance travel and the methods used to load and unload animals is urgently needed from the point of view of animal welfare and meat quality. Further studies need to determine if it would be better to allow animals to remain on the transport truck and continue their journey, with access to food and water on a ‘higher standard’ vehicle, or if it would be better to transport them shorter distances on a ‘basic’ vehicle and unload them for a rest period with access to food and water.
Cold winter
Because of their thin hides and lack of fur, pigs have very little cold tolerance. They lose heat rapidly and burn large amounts of glycogen trying to maintain body temperature. They are also extremely susceptible to frostbite. Both factors can greatly devalue the carcass. Even when outdoor temperatures are above freezing, wind-chill can kill pigs. It’s important to keep direct, cold airflow off animals while making sure there’s adequate ventilation and fresh air flowing through. Hogs will suffocate in airtight compartments.
Cold pigs may pile up or crowd together to stay warm. When this happens, injuries or deaths often result. Proper bedding material, plenty of partitions, controlled ventilation and taking whatever steps are needed to keep pigs warm will prevent pile-ups and ensure high quality meat arrives at the market.
Hot summer
Pigs have a low tolerance to high temperatures and high humidity. Unless precautions are taken, summer transportation can cause heat stress which may prove fatal.
Farmers and handlers must do everything possible to keep pigs cool and calm in extreme summer conditions. Carefully following recommended loading densities is the first step. Heat builds quickly in a stopped truck but heat build-up can be reduced by avoiding straw or shavings as bedding material and keeping maximum airflow through all compartments. If possible, farmers should schedule their shipments during evenings or early mornings when weather is cooler. Heated pigs must be cooled carefully. Spray animals with a fine mist or run cold water on the floor of the compartment. Never pour cold water directly on heated pigs. The shock may kill them.
Humane Treatment of Sick or Injured Pigs
Nobody likes to see an injured animal suffer. People in the hog industry know these animals should be put down as quickly and humanely as possible.
If an animal will be condemned at slaughter anyway, it should not be shipped. Examples of these animals include severely emaciated pigs, downers and pigs with multiple abscesses, rectal strictures, severe hernias or prolapsed uteruses.
Pigs with less severe conditions such as minor abscesses, mild hernias and mild-to-moderate lameness should be shipped early to minimize the pain and to prevent the condition from deteriorating. These pigs must be segregated during transport to prevent trampling and trauma from other pigs.
Some insurance companies have revised their policies so handlers can put down injured or infirm pigs first, then deal with the details of the claim later. This reduces the chance of needless suffering while establishing the validity of an insurance claim.
Federal regulations forbid loading injured or infirm pigs. They also prohibit handlers from reloading and returning pigs injured in transit. Remember, pigs must be fit in order to be transported.
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