in ksuvos 122a how were they allowed to give their animal 1/3 of their peach, one isn't allowed to give to animals human food?
Hello there and thanks for your interesting question. The source for the Halachah you mention can be found in Ta'anis 20b, where it mentions that on Erev Shabbos Rav Huna would purchase all the remaining vegetables from the vendors and dump them into the river. He would not feed them to animals since it is forbidden to feed an animal with food fit for human consumption. Rashi adds though that the vegetables would flow downstream and be eaten by people who found them. Clearly Rashi is of the opinion that it is preferable to feed them to animals rather than have them go to waste. But in this case they did not go to waste, as people discovered them further down the river. In our case, the option would be to either leave the remaining fruit to rot, or to feed it to the animals. Thus the correct thing is not to let it go to waste.
All the best.
1) There are two Pirushim in Rashi. See Mogein Avrohom O"C 171 s"k 1, Machatzitz haShekel there, E"R HaGohos C"S on the S"A whether the Halacha is like Rav Huna, see also M"B and Piskei Tshuvos Ois 1 and 8.
2) Where in Shulchan Aruch is the halacha about not feeding animals human food?
3) What are the restrictions on this? If the food would go to waste can it be fed to dogs?
4) What about food that you cook for yourself, for example chicken, can this be fed to a dog?
Halachic Disclaimer: For a halachic ruling, please consult your local orthodox Rabbi.
1) Yasher Koach.
2) Although the Shulchan Aruch does not seem to quote it, Yitzchok Zirkin above quoted many sources for this in the Acharonim.
3) If one wants, he can be strict and not feed human food to animals. However, there are many leniences in this matter. The Mishnah Berurah (171:11) quotes the Elyah Rabah as saying that we very possibly do not rule like Rav Huna, as indeed none of the primary codifiers (i.e. Rambam and Shulchan Aruch) quote this law. He also quotes the Machatzis Ha'Shekel who says that this is permitted according to everyone if one had nothing else to feed the animals besides human food. The Teshuvos Ksav Sofer (O.C. #33) says that there is no prohibition against giving your own animals human food, only giving it to the animals of others (see the responsa for other leniencies as well). Being permitted to give human food to birds seems to be the custom (see Mishnah Berurah ibid. and Minchas Yitzchak 3:45). In short, there are many leniencies in this issue. However, one should ascertain that he can be lenient in his particular situation.
4) See 3 above.
All the best,
P.S. The answers here are not halachic rulings, but rather information on the subject.