Shabbos, Mishnah 3. Like the previous mishnah, this one also deals with matters that involve exertion - that is, doing an excessive amount of work in order to feed an animal.
Three levels of feeding an animal:
"Ein ovsin es hagamal" - one may not fatten a camel by force-feeding it. Camels are famous for their ability to go a long time without food, and therefore people would stuff them with food in advance so that they could manage far longer journeys. Fattening of this sort on Shabbos involves an excessive amount of work.
"V'lo dorsin" - this too is forbidden. Here the food is not pushed down the way it is when force-feeding, but it is placed into the throat in a manner that the animal cannot bring it back out.
"Aval mal'itin" - this is permitted: when the camel does not want to eat, one places the food into its mouth, and the swallowing is done by the camel itself.
"V'ein mamrim es hagozalim" - the way people do with calves: one takes food, mixes it with water and pours it down their throat, until they cannot bring it back up, and this is force-feeding. This is forbidden. "Aval mal'itin" - just as with the camel, one may place the food in a spot from which they can spit it back out if they wish.
Further permitted forms of feeding:
"U'mehalkitin la'tarnegolim" - one may place food into the mouths of chickens.
"V'nosnin mayim la'mursan" - one may put water into bran, since this does not create a doughy mixture. "Aval lo govlim" - one may not do so in a manner of actual kneading, for that already presents a problem.
Giving water to animals:
"V'ein nosnin mayim lifnei tziporim v'lifnei yonim shebashovach" - one may not put out water for birds to drink, nor for the doves that live in the dovecote, because they are able to find water on their own, so this is exertion that serves no need.
"Aval nosnin lifnei avazim v'sarnegolim v'lifnei yonei hardisios" - yonei hardisios are a type of dove that King Herod raised in his palace. All of these, since they generally stay near the house and do not go out into the open on their own, will not necessarily find water unless it is supplied to them - and therefore one may supply them with water.