Herd of 2500 breeding sows

{
  "resourceType" : "Group",
  "id" : "herd1",
  "extension" : [{
    "url" : "http://example.org/fhir/StructureDefinition/owner",
    "valueReference" : {
      "reference" : "RelatedPerson/peter",
      "display" : "Peter Chalmers"
    }
  }],
  "identifier" : [{
    "system" : "https://vetmed.iastate.edu/vdl",
    "value" : "20171120-1234"
  }],
  "name" : "Breeding herd",
  "status" : "active",
  "type" : "animal",
  "membership" : "enumerated",
  "code" : {
    "coding" : [{
      "system" : "http://snomed.info/sct",
      "code" : "388393002",
      "display" : "Genus Sus (organism)"
    },
    {
      "system" : "https://www.aphis.usda.gov",
      "code" : "POR",
      "display" : "porcine"
    }],
    "text" : "Porcine"
  },
  "quantity" : 2500,
  "characteristic" : [{
    "code" : {
      "text" : "gender"
    },
    "valueCodeableConcept" : {
      "text" : "female"
    },
    "exclude" : false
  }]
}