- O-ring
- O-ring seal
- oblique agitator blade
- OCB
- occupancy cycle
- occupational safety
- ocular anomaly
- odd number
- odour
- oestrus period
- oestrus synchronisation
- off state
- off-premises warehouse
- offer
- offer
- offset
- oil boiler
- oil change
- oink
- on the pressure side
- on the suction side
- on top of one another
- on-the-floor feeding
- on/off control
- one-arm
- one-line
- one-way gate
- one-way restrictor
- one-way valve
- online shop
- open combustion
- open float drinker
- open house
- open run
- open run
- open-air pig house
- open-air run
- open-ended spanner
- opening
- opening for rope
- operate
- operate manually
- operating and maintenance instructions
- operating frequency
- operating hours
- operating instructions
- operating lever
- operating medium
- operating rod
- operating voltage
- operation
- operation
- operation manual
- operation unit
- operational reliability
- operator
- optical scale(s)
- optional
- optional extra
- order
- order entry
- order expired
- order form
- order processing department
- order-related material
- organic house
- organic layer
- organization chart
- oscillator
- outage of power
- outdoor management
- outdoor sow farm
- outer aisle
- outgoing goods inspection
- outlet
- outlet valve
- outlet with shutter
- output
- output device
- output terminal
- outside air flap
- outside diameter
- outside silo
- outside temperature
- oval head screw
- over-transport
- overall farm sanitation management
- overall performance
- overflooding mechanism
- overhead tank
- overhead winch
- overheating protection
- overlap
- overlapping
- overload
- overload protection
- overload relay
- overpressure
- overshoe
- overvoltage category
- oxygen measuring unit