Event structure

The event structure is the combination and interaction of events for a particular herd.  When you create a new data file an event structure is copied from an appropriate template file. Events can be added, deleted or amended until you reach an event structure that is ideally suited to your farm and system of management. 

A basic fertility event structure for a dairy herd is described below. While this would satisfy some farms, for others it would be too limiting and require additional events to allow for activities such as pre-breeding examinations, chemical pregnancy diagnoses, synchronisation of oestrus etc. The follow-up to the service event would need editing if the farm did not target pregnancy diagnosis 42 days after service. Clearly increased complexity in the structure will require a higher level of data entry but this is a decision for the farmer, not a limitation of the program.

Example of a basic herd fertility event structure in a dairy herd:

Event Results (options) Remarks / follow-up events
Calving
(CALV)
(a) Breed You wish to breed from this animal again. A "heat deadline" (HT-DL) event is scheduled (a follow-up event) for 50 days after calving to warn in action lists if no other fertility event is recorded within 50 days
  (b) Cull Not to be bred again. She is thus scheduled to be culled (CULL) at the end of the current lactation and will not appear on any further action lists relating to fertility.
Heat deadline
(HT-DL)
(a) Vet examination This event will only appear in action lists as requiring attention if no other fertility event is recorded (heat or service).  In this example the only result is to schedule a vet examination to determine any underlying problem.
Heat
(HEAT)
(a) Breed The animal was seen showing oestrus but not served. You want to breed from this animal so the event will schedule an expected heat event for 21 days later.
  (b) Cull The animal was seen in oestrus, perhaps after repeated services so you decide to stop attempting to breed from her. A cull event is scheduled for later in the lactation.
Service
(SERV)
(a) A.I. Following the service a pregnancy diagnosis event (PD) is scheduled for 42 days time. 
  (b) Natural As with insemination a pregnancy diagnosis is scheduled for a set period after service 
Pregnancy
diagnosis
(PD)
(a) Pregnant Pregnant will schedule a calving event (CALV) for 282 days after the service event (SERV). A dry-off date may also be set for 252 days after the service to ensure a 30 day dry period
  (b) Not pregnant -
Re-try
Not pregnant but want to try again. So a heat deadline event is set for 21 days after the PD to give the animal time to show oestrus. 
  (c) Not pregnant - Cull The animal is not worth persevering with and scheduled for culling at the end of the lactation.

See How do I develop an event structure appropriate to my farm?