Shabbos 20:3-4

Shabbos 20:3

One may not soak root sap in warm water on Shabbos but one may dip it in vinegar. One may not soak or rub animal fodder but one may put them into a sieve or a basket. One may not sift straw using a sieve, nor may one place it high up so that the wind will blow away the chaff, but one may place it into a sieve and bring it to the barn (even though some chaff will fall off on its own).

Shabbos 20:4

Rabbi Dosa says that, on Shabbos, one may sweep up in front of an animal that is being fattened and one may move the straw to the sides so that it won’t be ruined by the animal’s dung; the Sages do not permit this. One may take food from one animal and give it to another on Shabbos.