This mod changes the original cattle for new ones with real breed names and characteristics as it follows:
The Red Poll, Angus and Brahman won't produce milk, but its reproduction rate is faster so they're useful for raising and selling. The first two will eat more food and produce more manure, while the latter will drink more water and produce more slurry.
The Ayrshire and Holstein will produce milk in large quantities. Holsteins are a little bit more expensive and eat more than the Ayrshire, but they produce more milk.

Tried to make them as balanced as possible, so let me know if there's anything to be nerfed or buffed and I'll fix it. Also I'm not the creator of the base code for this, I edited Meliandah's "Animal Species" mod. Credits to him.