Commentary for Kiddushin 61:14

Pheasant: A prized and fatty bird. A type of quail (slav) that fell in the wilderness.

There is a son who feeds his father pheasant: The explanation - a prized bird. And it is a type of quail (slav) that is in the wilderness.

Causes him to be removed from the world: As he will be punished about him, since he showed him stinginess about his meal.

Causes him to be removed from the world: The explantion - as he will be punished about him, since he showed him stinginess about his meal. And there is [one] who makes him grind with a millstone - which is hard work - and brings him to the life of the World-to-Come: As he honors him by speaking good and consoling words to him. And the text in the Yerushalmi Gemara (Jerusalem Talmud Peah 1) has a story about both of them: The story of the one who feeds his father pheasant is [that] one day, his father said to him, "From where do you get all these?" He said to him, "Old man, what do you care, grind and eat" - meaning, chew and eat - "like dogs that are carefree and eat!" If so, he showed him that it was difficult for him. And also a story about the one who grinds with a millstone [is that] he had an old father and the king sent a requisition for mill grinders - meaning a command of the king for his father to come to [do] the king's work. His son said to him, "Father, grind; and I will go in your place to the king's work which has no limit. If it is for your disgrace, it will better for you; if it is for your lashes, it will be better for you."

And there is [one] who makes him grind with a millstone: Which is hard work.

This tradition is found more elaborated in the Yerushalmi, and it is basically impossible to understand the Bavli without the Yerushalmi. There we read:
There is one who feeds his father fatted birds and inherits Gehenom and one who ties his father to a mill and inherits heaven.
How is it that one can feed his father fatted birds and inherit Gehenom? There once was a man who fed his father fatted birds. Once, his father said to him, “Son, where did you get this?” He said back, “Old man, eat and shut up like a dog.” It turns out that while he feeds his father fatted birds, he still inherits Gehenom.
How is it that one can tie his father to a mill and still inherit heaven? There once was a man who was a wheat-grinder. A command came from the king to the grinder. The son said to his father, “Father, grind in my place so that if they come to disgrace or beat (one of us) better they should disgrace or beat me and not you.” [The king would first take those who were not working]. It turns out that he ties his father to the mill, and still inherits heaven.
We should note that it in all of these sources the parallel in the Yerushalmi is usually easier to understand. It seems that the Bavli inherited its sources in some sort of truncated form.