the gemara says that when you have a doubt as to when the animal was born it says just leave it by the one who has it, and the other person involved in the dispute will have to bring proof that it his, so i understood the gemara to mean a chezkat mamon, but i dont understand why that is a reaon to say that it is his, b/c over here the question is when was the animal born, so just because it is in my hands how does that prove that it was born by me, but the standard case of chezkat mamon where the claimer says you owe me 20 dollars and the defendant says no i dont then you can say since we know that he owned the money before this question arose, so bring me a proof that he no longer owns this money and this type of a doubt is a doubt if i still own the money or maybe its not mine, but the doubt in the gemara by us is a doubt if i ever owned the money so what is the chezkat mamon
samuel engle, new york , usa
TOSFOS (DH "v'Lechzi") addresses your concern, but concludes that the original owner of the animal is actually like the person in your parable who has a claim against him for twenty dollars. As you explained, since we know that the person owned twenty dollars previously, one would have to bring proof to take it out of his hands.
In the case of the animal, we know that the original owner owned an animal that was extremely pregnant. Though Tosfos concedes that we do not know that the original owner ever owned the animal, Tosfos concludes that the fact that he definitely owned the almost-born animal is enough to say that he is considered like a bonafide Muchzak of the animal.
Kol Tuv,
Yaakov Montrose