This is one of those debates where I believe there is no clear YES or NO answer.
I believe the reason why people feed hay during travel is because they feel that their horse is more relaxed and settled in the float/truck if they have something to eat.
And I think this is certainly a valid point.
I am one of those people who never feeds their horses on the float/truck and I’ll give you my reasons which might give you something to ponder on so you can make your own decision.
One reason I don’t feed hay during travel is that horses are often restricted how low they can put their head while tied up and possibly restricted by a chest rail.
The reason it is important for horses to lower their head while eating is because of the risk of choking.
If a horse is eating too quickly, greedily, or just doesn’t chew enough, there is a risk that the horse might choke. This happens when they get food stuck in their throat.
If the horse is not able to put its head down to get rid of some of the saliva that is building up, then that could cause problems.
Also the horse needs to lower its head to cough, to get rid of any food that might have irritated the horse during eating.
The other reason is that some vets believe that feeding horses during travel can increase the risk of travel sickness.
So, when you are traveling with your horse, maybe consider taking a hay net with you and feeding your horse as soon as you arrive at the venue you are going to.
Whenever I travelled long distances with my horses I would stop after 4-5 hours and get them off the truck to let them have a bit to eat and offer them fresh water. After a little rest they were ready to get back on the truck.
I made a point to never drive longer than 8 hours per day.
So if you are going to an event or to a clinic and you have a 2 hour drive, your horse will be absolutely fine to not eat for that period of time.
And like always, do your own research so you can make your own informed decision that you are happy with.