One of my villagers has gone inactive for a month vacation and I have been taking care of the rabbits that belonged to her. I was always told by other players that rabbits are not worth it and make no sense in the game. After a month of trying to find a good use for them I come to the same conclusion.
Lets take the two coop animals in the game side by side.
Quality-
After a month of breeding these rabbits I have gained 10 quality. That is 4 coops, ran just like my chicken coops. However, my chickens raised 30+ points.
Feed-
Rabbits SEEM to require alot more swill/water as well. I dont have proof for this other than me thinking "Did I not feed these guys just the other day?" Maybe its contributed to the fact that giving them swill is not as worth it as giving it to chickens, next point.
Products-
rabbits give bones, meat, and pelt. Same as wild rabbits. 1 fur or 1 leather value. 2 meat. and 1 bone. Chickens however give raw chicken meat (1x), feathers (3x), and bone material (1). Aswell as sometimes a wishbone (Common, extra bone material). We will ignore lucky rabbit foot and golden egg. However; lets not forget that chickens give EGGS. The bread and butter of baking (not literally). Rabbits give nothing else. Cows or pigs give 4 leather as well as meat/milk which overshadow rabbits making them worthless. Chickens give eggs and feathers which make them unique and valuable.
Breeding time-
Chickens breed way faster than rabbits in game. Not sure the exact numbers. IRL Eggs take 21 weeks to fully grow into fertile adults. Rabbits take 24 weeks from impregnation to being fertile adults. not much of a difference in real life. An egg takes 24 hours to be lain in real life as well in game. Rabbits take 30 days to lay a litter of 8 kits. I can fit 11 rabbits in with one buck. I should be getting 3 babies PER day PER hutch. That is not whats happening as far as I can tell.
A quick fix would be to make baby rabbits not eat as much as adult rabbits and increase birth rate of baby rabbits. Not sure the growth rate of rabbits but its about the same in real life as chickens so it should match chickens as well.