Overview of the Rotation Program.

 is a simulation program that takes the significant input variables of a rotationally grazed pastoral farm and dynamically models the results on a 12 hour or 24 hour basis by allocating each herd to the best matching paddocks according to preset grazing policies.

New users of will move through a sequence of pages to input the key data of their farm. Once the base farm is established users will simplyneed to modify elements as the seasons progress or stocking of the farm changes.

Regular Pasture Readings are the Main Input

The initial setup of the farm's paddocks and herd numbers and feeding rates and policies is retained in your individual and private record on the  database. Subsequent to setup the most important input for each run is today's cover or dry matter reading for each paddock of your farm.

Much effort can be put into obtaining accurate pasture cover readings with specialist equipment. Our experience showed that with capable managers and staff, visual readings could be obtained with sufficient accuracy for the simulation. However, these visual readings should be regularly recalibrated from time to time a grass meter, (such as a falling plate  or an electronic grass meter) to ensure ongoing accuracy.

We recommend grass readings are done every ten to fourteen days to ensure the paddock covers used by the program closely match the actual farm situation of the planned rotation. The more variable the daily growth rate the more frequently a new reading should be taken.

With each new farm pasture cover reading the simulation should be rerun to produce a new rotation plan.

The next most important input is the projected average daily growth rate of the farm for the period of the simulation. This figure is the basis of the simulation's individual paddock growth rate. Your experience with growth rates on your own farm will be the best guide, taking into account current local climate, soil moisture and temperature conditions.

The Model Growth Curve

The simulation's growth equation includes a model growth curve   reflecting the normal pasture growth pattern of recovery, sustained growth, followed by senescence according to the cover present on each paddock.

The growth and cover curves shown in the adjoining table are representative rather than a precise description of the growth formula employed by the simulation.

The simulation uses an individual paddock growth rate formula to compute each paddock's daily growth rate according to its daily cover. Therefore, paddocks grazed to a low cover will have a lower growth rate in the initial recovery period and conversely paddocks with a high cover will eventually reach a nil or even negative daily growth rate in accord with the standard pasture growth curve used in the model.

Rotation Reports

With all the relevant inputs entered, the simulation is run and a number of reports are produced.

The most important of these is the planned rotation report which lists the paddocks selected by herd, the in-going and out-going covers and the feed required and if necessary with supplements for each herd for that day.

The simulation can be run to produce a rotation plan for up to six weeks ahead. However, fine tuning is needed to ensure the model does not run out of feed for any herd if the model is run for the maxim period.

If available feed is insufficient on any day in the run the simulation stops and reports accordingly. Adjustments can then to be made to both the level of pasture fed and an amount of supplementation introduced to enable the program to complete its run.

Feed Supplementation

Feed supplementation options utilizing feed reserves in the form of hay, silage, green feed or concentrates are included in the inputs and these should to be set according to the planed herd feeding levels and the probable grass growth.

A further supplementation tool is available from the application of nitrogen to increase the projected grass growth of individual paddocks to be included in the rotation.

Harvesting of Surplus Feed

In situations where growth exceeds consumption and the cover of individual paddocks exceed the maximum grazing levels, paddocks are notionally harvested for hay or silage according to the settings and the harvested feed is added to the reserves held.

Although the  program was originally developed for dairy farm management it adapted well to bull beef production and it can be utilised by sheep managers who rotationally graze sheep or beef.