Derrick felt really self-conscious for the first hour or so, moving around naked in full view of others. It helped some that no one else wore clothing, but that was also embarrassing for other reasons. The freakish horse-boy creatures were rather spectacularly endowed sexually, and lacked the bowel or bladder control that the centaurs displayed. True, they did clean up after themselves immediately, using their odd, flat three-fingered hands like rakes. There was also a lot of contact - these were very social creatures that lipped and nuzzled and stroked each other constantly when they were not busy mucking stalls or grooming residents.
He was shown how to muck stalls with his hands, which was gross, and the manure pile where the soiled straw was dumped, which was grosser. However, as he did more stalls, the job got easier and less disgusting. The stink and the flies and the sticky mess didn't change, but by early afternoon he realized none of that bothered him at all. Funny what you could get used to. His 'teacher' had him take a break, where he shared water from a spitty bucket and grain and oats from a large trough. Derrick hesitated when he saw the spittle and bits of grain floating on the water, but realized he was too thirsty to care. Three million would buy a lot of bottled water later on.
Oddly, the work got easier in the afternoon. though it seemed to be just as much as before. The horseboys were including him in their grooming and socializing, which was sort of like being surrounded by huge, friendly dogs. Not that he would admit it to anyone else, but Derrick found he was enjoying himself. While the work was repetitive and almost endless, the boy felt a sense of accomplishment when he left a stall clean and fresh.
The dinner break was like the lunch break, but this time Derrick did not hesitate either to drink or eat with the others. Work continued for a few hours afterwards, and then the horse-boys gathered in a common cleaning area to wash up. It was here that Derrick looked into the first mirror he had seen since he started. He did not realize it was a reflection at first - the image looked a lot like one of the horse-boys, but was smaller and far less bestial. Halfway between a human and a horseboy - and then Derrick realized that he was looking at his own reflection! His arms and legs had elongated, and his face with protruding out. A shadow of hair had spread over his entire body, and the shape of his skull was flatter. He was also a lot larger sexually, the shape more like one of the horseboy's dark shafts.
Derrick stared at the mirror for a couple of minutes, trying to pin down his feelings about the changes. He felt confused - knowing that he was human, but also understanding how much better the horseboy's shape was for the job. A couple of his coworkers came to press against him, and he had to admire their far horsier appearance. They looked 'right', while he looked incomplete. He was still musing over what he should look like when he drifted off to sleep in the arms of his teacher.