You decide to make him act like you but you don't give him the ability to talk or intructions ,because someone could get suspicious if he said the wrong things or didn't know how to react due to insufficient instructions.
You DO decide to take his place though to keep an eye on him.
You immediatly go to work and start to influence the former bull into believing that she is a Queen, who happily turned herself into a dumb obedient cow for the farmer and his wife to use in any way they want.
The panicing cow is slowly starting to calm down by now but still looks slightly confused.
You consider for a moment wether this will really work, before adding that the reason why she isn't using her powers or speaking, is because she enjoys being treated like cattle by the farmer so much that she wants to have the full expirience of being a cow.
The cow's confusion is rapidly fading and completely disappears, when you transform yourself into a bull almost instantly and make her think that you are just normal livestock.
The sudden transformation makes you a bit dizzy and confused for a moment, before you can gather your bearings.
You look down to see that you are now a large muscular black bull with impressive horns.
And an even more impressive erection.
You stop for a moment to calm down, but only get more aroused when you get a whiff of a musky odor comming from somewhere close to you.
You look up to see the cow staring at your erect cock and with lust in her eyes.
The cow suddenly turns around and backs up, shoving her moist snatch into your face.
You try to back up but can't resist taking a deep sniff of her scent.
The pheromones immediatly get to you, makeing your mind sluggish and thoughts slow.
You feel yourself losing controll.