What is an Animal Unit?

An animal unit rating is an animal’s energy demand relative to that of the defined standard animal. Energy demand is largely a proxy for dry matter intake, i.e. how much pasture an animal eats.

Animal units are a way of comparing animals of different classes and species so they can be expressed in a standard format. The most common animal units are an AE (Adult Equivalent) for cattle and DSE (Dry Sheep Equivalent) for sheep.

Animal Units can be used for property valuations, business analysis, enterprise analysis, determining carrying capacity, feed budgeting, etc.

Therefor, they need to be calculated accurately and consistently for them to be useful in establishing accurate information to be used in any of the above situations.

Animal units are also primarily used to record your stocking rates and grazing load on pasture. These unit systems differ around the world. You can pick the most appropriate unit system for your property based on your current location or pick a different unit system.


AgriWebb allows selection between the following Animal Unit Systems for various countries:

Australia

  • Dry Sheep Equivalent (DSE)
    Based on a 2 year old 45 kg Merino sheep (wether or non-lactating, non-pregnant ewe) at maintenance.
    1 DSE = 7.6 MJ ME/day

  • Large Stock Unit (LSU)
    Based on a 400 kg steer at maintenance.
    1 LSU = 49.4 MJ ME/day

  • Livestock Unit (LSU)
    Based on a 425 kg feeder steer at maintenance.
    1 LSU = 52.4 MJ ME/day

  • Adult Equivalent (AE)
    Based on a 450 kg Bos Taurus steer at maintenance, 2.25 years of age, and walking 7 km each day.
    1 AE = 72.6 MJ ME/day

New Zealand

  • Stock Units (SU)
    The base ewe was assumed to weigh 55 kg (pre-mating), wean one lamb at 25 kg and consume 550 kg DM per annum.
    1 SU = 10.5 MJ ME/day

South Africa

  • Large Stock Unit (LSU)
    An ox with a weight of 450kg and a weight gain of 500g per day on grass pasture with a mean Digestible Energy (DE) concentration of 55%.
    1 LSU = 75.0 MJ ME/day

  • Small Stock Unit (SSU)
    The definition of the SSU is relative to the South African LSU where 1 LSU = 6 Small Stock Units.
    1 SSU = 12.5 MJ ME/day

UK

  • Livestock Units (LSU)
    Based on a 650 kg dairy cow producing 3000 kg of milk annually.
    1 LSU = 124.9 MJ ME/day

USA

  • Animal Units (AU)
    The animal unit is defined as one mature 1,000 pound cow and her suckling calf. It is assumed that such a cow nursing her calf will consume 26 pounds of dry matter (DM) of forage per day (20 lbs for the cow and 6 lbs for the calf).
    1 AU = 89.6 MJ ME/day


You can update your animal unit selection on either the Mobile App or Web App. The option is set per farm.

Mobile App

On the Menu tab select Settings

In the Units of Measurement section, tap Animal Units to select between the available options.

Web App

Select Account from the navigation, and then click Farm Management


Find your farm in the table, and from the Edit dropdown select Settings

A window will pop up allowing you to select from the Animal Units options.



Sources for definitions 

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