Cows are probably less productive per unit of work investment than sheep, but they're a prestige item. I bet there are Norse who manage to get a weak Orthstirr trickle out of their reputation as a cattle rancher. No one ever got an Orthstirr trickle out of their chickens or goats, I bet.
Cows can provide a lot of food in the form of milk, I think them providing objectively the most Goods per Property if you had unlimited money (since they're also very pricey) is fine. Sheep and Goats doing better if you put in two Property may be good enough that they should also provide an Orthstirr trickle, though.
So that'd be something like the following:
-One unit of Chickens requires 1/2 Property (rounded down) but produces only 1 Goods.
That means you can get 1 Goods per turn for free (well, for the money up front), but after that it's 2 Goods per Property, so it doesn't scale well beyond that. Every farm will have a few chickens but few will have many more.
-One goat will get you 2 Goods per Property invested (max of 2 Property per Goat), but don't get sick unless you put in zero.
Not any better than chickens, but presumably cheap, and gets you full use out of your Property even with only a few.
-One sheep will get you 3 Goods per Property invested (max of 2 Property per Sheep), but don't get sick unless you put in zero.
Best per animal return rate available. Very solid. Most farms will have some extra Property at some times of year and will thus want a few of these to utilize it (we, for example, use 6 more per turn in Summer than Winter due to Fields).
-One Cow will cost you 1 Property per turn but get you 4-5 Goods in exchange, and every X Cows (probably 3 or so?) get you +1 Orthstirr a year.
Best per Property return, on par with a field (or slightly better? Maybe if Fields cap the number of animals in some way...4 Animals at most per Field would make sense) and adds a small amount of Orthstirr to boot.
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That leaves out pigs because I'm still not sure how baby animals are being handled. If they still fall under 'Goods' then we can work something out like the above. If not, then we need a 'how much you get when you kill them' chart and Pigs provide nothing while alive, but a lot of meat when dead and breed extra fast (which lets you slaughter more of them).
That otherwise looks good, though it admittedly it's still missing anything for Animal Quality and how that would work.
Maybe we can just go full coweconomics? Just saying.
The thing is that the Norse didn't actually do this. They had cows, yes, but not
exclusively, so going All Cow should not actually be the optimal choice for reasons of verisimilitude.