Inference (R. Ze'ira): (Our Mishnah teaches that if he was Gozel a pregnant cow and it gave birth, he pays for a cow about to give birth.) This shows that if one was Gozel a fat animal, and it weakened, he returns to him [the value of] the [lost] fat.

Inference (Rav Chisda): [Our Mishnah] teaches that if one was Gozel a thin animal, and it fattened, he returns to him intact. [The Mishnah says that] because it became pregnant and gave birth, he pays the value at the time he stole it. (If it were still pregnant, he would return it intact.)

Question: Who taught [the general rule in our Mishnah, that all Gazlanim pay k'Sha'as ha'Gezeilah]?

Answer: It is R. Yakov, for a Beraisa teaches 'this is the general rule that R. Yakov used to say. Every Gezeilah that is intact, that did not change bodily, he tells him 'yours (what I stole) is in front of you';

And a Ganav (covert thief) always pays k'Sha'as ha'Geneivah. (NO'AM YERUSHALMI - the Yerushalmi holds that for Geneivah, he despairs immediately, and the Ganav acquires through despair alone.)