MISHNAH: ONE MUST NOT STUFF A CAMEL. [WITH FOOD] NOR CRAM [IT]. BUT ONE MAY PUT FOOD INTO ITS MOUTH; AND ONE MUST NOT FATTEN CALVES, BUT ONE MAY PUT FOOD INTO THEIR MOUTH. AND FOWLS MAY BE MADE TO TAKE UP FOOD
Although one has a responsibility to take care of animals on Shabbat, including to feed them, this Mishnah specifically disallows the forced feeding used to artificially fatten an animal. The rabbis discuss various forms to glean the meaning – including forcing food down by hand and with a utensil. This practice was attested even as far back as ancient Egypt (2500 BCE) and would have been known to the rabbis through the practices of the Roman empire. It continues today, for example in the making foie gras.
. . . AND WATER MAY NOT BE PLACED FOR BEES OR FOR DOVES IN A DOVE-COTE, BUT IT MAY BE PLACED BEFORE GEESE, FOWLS AND HARDISIAN DOVES
Although it is a responsibility to care for animals (and not to overcare to their detriment) on Shabbat, it does not include when the animal has the ability to fend for itself – i.e. bees who can easily find their own water.
Dogs, for example, who were semi-domesticated – could barely scrap out a living and thus it was proper to throw them some raw meat. Domesticated pigs were fed, even though in theory they could find their own food.
Thus a saying of R. Papa:
None are poorer than a dog and none richer than a swine.