Horse / donkey jump meter isn't the same length as the experience bar

Horse / donkey jump meter isn't the same length as the experience bar

 

Steps to reproduce :

Tame a horse or a donkey and ride it

Jump with the horse 

Observed results :

The horse / jump jump meter isn't the same length as the experience bar

Expected results :

The horse / donkey jump bar should be the same length as the experience bar