Add breed for small set of "livestock" species

[brianraymor]

Context

There may be a different open issue for livestock in general - breed metadata. FAANG defines separate fields for organisms and breeds - - using the Livestock Breed Ontology (unavailable on OLS) and this guidance. Also see samples.

Breeds are limited to:

• buffalo breed
• cattle breed
• chicken breed
• goat breed
• horse breed
• pig breed
• sheep breed