I'm going to put this down to over exuberance since you've only been a member for a day, but there are a reasonable number of us here that might take issue with such statements like: an animals purpose is to bring humans happiness, and they are meant to be Fucked Hardcore.
In any relationship or sexual encounter there must be respect. Otherwise it can be quite abusive!
You need to be sure that the animal is happy and comfortable with you being more forceful with them. When I am balls deep in a cow or bull, I can be slamming into them pretty hard, because they weigh 10x my weight and my thrusts are unlikely to barely move them if at all, yet I am constantly aware what they are doing, their body language, sounds they are making, etc. If they show even the slightest sign that they are unhappy or don't like the way I am humping them, I ease up if not stop completely depending on their reactions. They must be a willing participant in the activity not just a hole to get off in.
In comparison, even the largest Dogs are much smaller and I would never be as forceful with them. if they are really into it, most dogs will move back to meet your thrusts anyway, so there is no need to start off like a sledge hammer, if they want more they will let you know. But you must always listen to what they tell you through their body and actions.