They shift weight to become more comfortable
it depends on the weight of the horse
The weight of an adult horse depends of the height and breed of the horse, also what type of work the horse is in.
to find a estimated Weight of a horse
No One can shape shift IRL. Unless you count weight loss/weight gain.
Another horse, or a saddle.
press shift
the horse head weigh as much as 11.5 or 26 in proportion its body weight..
Their weight is from 900 to 1000 lbs.
Yes the amount of exercise will affect a horses weight. If the horse is overweight it will slowly lose weight through exercise, just like humans. If the horse is a good weight and is being fed correctly then instead of weight lose you'll get muscle gain and the horse may go up in weight as muscle is heavier than fat.
To dismount a horse, just use the left shift button. This is the same for getting out of minecarts and boats.
If you go into sneak mode (hold left shift) and right click on the horse, you will open its inventory so you can equip it with horse armour and a saddle.
First, you must place a saddle on it and the horse must be tamed. Then, right click on the horse and left shift to dismount.