Everybody hates how much livestock eats. But I think the real problem is how much livestock you have to breed to see decent quality growth. All those pregnant females hoovering up the troughs take fodder requirements much higher than they'd be if you were just feeding animals for your daily milk and wool needs. Also, breeding tons of babies to get lucky with the RNG leaves you with a lot of animal corpses that you don't really need, devaluing domestic meat to the point where you can't even be bothered to butcher it and removing corpses from the base becomes a chore. Not to mention how much of a chore it is to actually sort through the babies and select the next breeders, especially when you have to do it in crowded pens. And mass breeding is terrible from the LARPing perspective, it makes individual animals feel so generic and forgettable. I doubt anyone even bothers naming their animals any more, except maybe their horse.
What I propose is to change the animal stat raising system so we go through a lot less animals. Namely, instead of getting increases through RNG you'd get them on an individual animal by doing quests for that animal. These increases would be partially inheritable, ie the effective stat for producing offspring would be halfway between what the parent was born with and what it achieved via credos. No randomization from this base to remove baby spam, but breeding stat caps it as usual. The idea here is to prevent mass breeding of a high stat once you raise one animal up. Instead you'd have a limited supply of top tier products like milk from the credo cow that you'd save for the important recipes like butter steamed bulbs, and a bigger general use supply of lower quality milk from the unquested babies bred from that cow.
Retaining some RNG could be fun, though, and where I see room for that is in selecting the base stats for a new baby - instead of averaging both parents' stats it could roll randomly for each stat to inherit unmodified from either parent. This wouldn't really matter if you bred similarly statted parents, but it'd make combining breeds involve a bit of luck. And different breeds might actually be a thing if baby spam is reduced, because it'd increase the value of meat and wool quantity stats.
Now, the credos themselves would work pretty similar to your character credos. But instead of being tied to you, they'd be tied to an individual animal. This means you could be doing credos for multiple animals at a time, or even multiple people working on one animal. These credos' rewards would be a bit simpler, though. You just select one stat you want to work at, and each level gives +1 in that stat. Completing a credo lets you do another credo on the same stat, so there's no theoretical limit on how high you can push an individual animal. But quests per level would increase as it does for character credos, so there'd be a practical limit where you just have to stop and restart with the next generation.
The nature of the credo quests could vary, but I think there's room here for some interesting meta changes. For example, we could have quests that involve taking livestock outside of your base, which would open up a new PvP venue - cattle rustling. Off the top of my head, examples of such credos would be taking your animal to x terrain type, having it graze on x foragable (you have to bring the animal to the unpicked foragable), taking it to a questgiver or even sharing an experience event with it. Or we could have some safer quests that can be done at home, like bringing your animal some delicacy (carrot cake and stuff like that), playing a tune on an instrument for it or giving it a good scratch. A mix of both types would be best, and IMO it should be weighted more towards outside quests as the base quality of the animal increases.
Another use for animal credos could be learning tricks. When we get dogs we could teach them various commands and combat moves by doing appropriate credos. And hell, why not teaching horses tricks while we're at it? Unlike stats, tricks would be uninheritable. Not only is it realistic, but it'd drastically increase the value of a well trained animal, and all the time you invested working on that animal will make you care a lot about that special dog you got so you're definitely gonna name it.