The Animals in Context Ontology (ACO) includes classes that develop when animals are put to practical use. These classes are commonly invoked by individuals involved in animal husbandry, production and veterinary care. A few of these animal classes are imported from the recognized Linnaean hierarchy and are actually common synonyms for the scientific names. Most of the ontology extends the Linnaean hierarchy by referring to various life stages (e.g., calf), production classes (e.g., broiler chicken), circumstances of husbandry (e.g., zoo animal), physiologic and age-based classifications (e.g., heifer) and common non-Linnaean groupings (e.g., duck).
ACO was developed collaboratively by following the OBO Foundry principles. ACO is interoperable with other OBO ontologies because it is built under the upper level scientific ontologies Basic Formal Ontology (BFO) and BioTopLite, utilizes common relations, and re-uses classes from external ontologies such as NCBI Taxonomy, Environment Ontology (ENVO), Gene Ontology (GO), and Phenotypic Quality Ontology (PATO). Classes in ACO feature text definitions, formal definitions, synonyms, and a link to an equivalent VTSL SNOMED Extension class. The ontology is formatted in the common syntax OWL-DL and is open to additions.