I get the feeling you donāt have much real life experience with cattle. The only practical difference between breeds is between dairy cattle and beef cattle. In a game about colonial warfare, this is a minor distinction and not worth the needless complexity.
The reason the euro civs donāt use cattle is because cows are gated behind cards and take a lot of APM to manage.
The first problem to solve is to make cattle accessible without needing to give up a card. I think the best way to implement that would be through buffing the Naturalist Politician.
The Naturalist
Ships 2 Settlers and 2 semi-fattened Cows & enables training cows at the livestock pen
To give a reason to still send the Ranching card, some adjustments would be needed. The base cost of cows should be increased to at least 100 to make the Naturalist buff a little more minor. Next, the Ranching card should be buffed as follows:
Ranching
Enables training cows at the livestock pen & -20% cost for all livestock (this keeps it the same for cows, but it now also buffs sheep). Possibly also deliver a couple of skinny cows.
The next step would be to give livestock a way to generate resources in a way that doesnāt require so much micromanagement. I think the best way to do this would be to have a card that enables livestock to be tasked to pens to be milked/sheared. The least intrusive way to do this would be to have them function like a Japanese shrine. This could be enabled through an Advanced Livestock Pen card.
Advanced Livestock Pen
Livestock Pens are cheaper and stronger & Livestock Pens generate a small trickle of resources when fully fattened livestock are tasked to them
Cows, water buffalo, goats, etc. produce milk (pens generate food)
Sheep, llamas, yaks, etc. produce wool (pens generate coin)
Larger animals would contribute more to resource generation
European civs already have decent economies so this ability should definitely be locked behind a card so they have to exclude something else to get the benefit. The rate of resource generation should also be modest, and not as fast as the rate African cows generate. The number of Livestock Pens should also be limited to prevent this from being abused in treaty games. A build limit of ~5 would be a good start, and shipments like 7 Sheep + 1 Homestead Wagon or Advanced Livestock Pen could increase the build limit by 1 for each one sent.