Animal Wellbeing

Transport of Commercial Slaughter Horses – Dehydration

The existing regulations for the transport of commercial slaughter horses in the United States and Canada are largely based on a series of studies conducted at Texas A&M funded by the USDA Veterinary Services. Also, these studies have been featured in federal litigation and state hearings on the issue. Past studies conducted at two other universities had found that stalled horses could be deprived of feed and water for 5 to 7 days and recover with no lasting problems.  However, our studies found that detectable dehydration starts occurring during transport in hot conditions after 24 hours, with significant dehydration and fatigue occurring after 28 hours.  Although providing horses with water during transport moderated dehydration, fatigue still became significant after 28 hours.

Transport Stress of Horses – Rest

Applied studies conducted at A&M demonstrated that the European Council’s proposal for regulations requiring frequent off vehicle rest stops and the associated unloading and reloading of food animals were detrimental to the wellbeing of most agricultural animals.  Horses and sheep did not actually “rest” during rest stops, but explored and remained active until they became fatigued.  Although many animals ate and drank water during stops, there is a tradeoff between getting the trip over as soon as possible and greatly prolonging the transport event when, for example, 6 hour rest stops are mandated at 8 hour intervals.  The European Council then revised and implemented more reasonable regulations, although some aspects of their regulations are still poorly researched.  When determining duration of transport for horses, “rest stops” should often be included as time spent in transport. The optimum duration for a rest stop to be useful in mitigating transport stress has not been determined, but 12 hours is not enough time for normal rest patterns to be re-established.

Horses Feeders for “Sloppy Eaters”

Horse owners are often faced with the dilemma of having one or more “sloppy eaters”.  These horses typically take up large amounts of feed in their mouths, raise their heads out of the feeder to apparently look around, and then much of the feed falls out of their mouths as they start mouthing and chewing the feed.  Much of their feed ends up on the floor of their stall or into the dirt or sand when fed outdoors.  In addition to wasting a good portion of the feed, such horses also then try to eat the contaminated feed after what was in their feeder ends up on the floor.  The contaminated feed is mixed with sand, manure, and other debris which are eaten by the horse and can cause major health issues for the horse.  Studies at A&M evaluated four different types of feeders, and determined that feeders with 8 cups molded into the bottom greatly increased time horses spent eating and significantly reduced the amount of feed dropped on the floor. The most wasteful horse on the study lost 32.8% of his ration when fed from a conventional bucket, but that was reduced to 8.7% when fed from the feeder with the molded cups in the bottom.  This type of feeder would be especially useful when managing sloppy eaters, but it is more expensive and requires more cleaning.

Transporting Horses in Groups or Individual Stalls

Whether it is better to transport horses in loose groups or in individual stalls has been a controversial issue. Studies at A&M have indicated that transport in loose groups is comparable or in some situations preferable than individual stalls, as long as the groups are observed in pens prior to loading and aggressive stallions or mares are removed from the group and transported individually.  The European Union, however, implemented regulations that all horses being transported to slaughter be transported in individual stalls.  The individual stall requirement has created a host of “unexpected” welfare problems for the horses that welfare groups have exposed and are campaigning to remedy, but there appears to be little interest among European regulators to revise the regulations.

Transporting Horses in Groups

There has long been a myth that when horses are transported in groups, they should be loaded very tightly so that they “hold each other up”.  Studies conducted at A&M have shown that horses do not hold each other up, but impede each other’s ability to maintain balance.  High density transport is also associated with more injuries and it makes a horse that does lie down during transport more likely to be trampled.  Horses also avoid contact with walls and others horses during rough roads, turns and abrupt stops.  When loose groups of horses are being transported, they should be given more room during shipments of 24 hours or longer than during shorter hauls.

On-truck Watering System for Groups

An on truck watering system for horses being transported in loose groups in commercial semi-trucks was developed and tested. A float valve plastic waterer that was mounted on a bracket that could be inserted into the animal compartments was utilized by horses when the truck drivers stopped at truck stops for a meal and rest brakes.  Most of the horses readily drank and did so within the first 30 minutes of access to the water, so the system appears to be practical in delaying dehydration during long shipments.  Implementing this or a similar watering system will require changes in our current regulations, which is not likely at present.

All the above research was conducted by retired animal science professor Dr. Ted Freind. For more information about any of the research above please email Chelsie Huseman at 

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