Perform predictive seasonal stocking

This activity forecasts the pasture biomass after a defined period of time and destocks the herd to ensure a minimum pasture biomass is retained. This aims to ensure that pasture is not overgrazed and there is no decline in land condition. It is assumed that there is no further pasture inputs through pasture growth during the assessment period as would be expected in monsoonal tropical/semi-arid dry season. The types of individuals that can be destocked are defined by a number of components supplied below this activity. For example, you may wish to destock all males not sires, followed by poor condition and dry breeders, then old breeders. The Manage ruminants activity has a parameter that defines the pasture level before re-stocking is again undertaken.

The following parameters are used to define this activity

Assessment Month

The month in which to perform the assessment and sale of individuals.

RequiredJanuarytoDecember

Number of Months to assess

The number of months to account for into the future.

Required>0

Minimum pasture at end of period

The minimum biomass of pasture (kg/ha) permitted at the end of the assessment period.

Required>0

Insufficient resources available action

This parameter will determine what action is taken if there are insufficient resources to perform this activity.

You can report an error and stop the simulation, skip this activity or use the resources available. See What to do when resources are limiting

The following components are required to use this activity

Ruminant groups

This activity contains any number of Ruminant group components where each defines the individuals that can be sold in order until the required reduction is achieved, or there are no more suitable animals to sell. These groups must have a style set to Reduce

The following components will add additional functionality to this activity

Labour Requirement

Any Labour requirement will include labour allocation to perform this activity based on any specified identifiers and units and may limit the outcomes if supported and OnPartialResourcesAvailableAction set to UseAvailableWithImplications

Activity Fee

Any Activity fee will include financial costs based on any specified identifiers and units and may limit the outcomes if supported and OnPartialResourcesAvailableAction set to UseAvailableWithImplications

Timers

This activity will occur in every time-step unless timers are used to restrict this activity (see Using timers).

Ruminant Activity group

This activity will obey all Ruminant activity group in the simulation tree at and above it's location.

Only one instance of this component is permitted in each Activity.

This activity performs a simple prediction of pasture biomass in the assessment month based on the specified assessment period. This is usually performed during periods where no pasture growth (rainfall) is expected such as the dry season in the rangelands of northern Australia. Therefore it assumes no pasture production will occur during the assessment period.

For each month of the assessment period, including the moth of assessment, the pasture lost through detachment is predicted. As two different detachment rates are provided when describing the Graze food store type and there is no easy way to predict the age of pasture through time, this activity uses a detachment rate 2/3 of the difference between the monthly detachment rate and the old pasture carryover detachment rate. This value (approx 9%, given 3% and 12% detachment and carryover detachment rates respectively) was found to best predict pasture biomass.

Each month of the assessment period, after the assessment month (as consumption has already occurred when this event is performed), the pasture consumption is removed based on the total adult equivalents present and a monthly feed required calculated as 2% of body weight.

The assessment does not consider mortality during the assessment, nor does it consider future sales and purchases. In order to influence other activities purchasing individuals in a period of low pasture biomass you would need to include a Pasture level timer on those activities.

You may need to investigate when and how successfully seasonal destocking was attempted. In order to achieve this a number of properties as well as a report status event are provided. The details for the event are provided in Seasonal destocking status report and will provide the estimated pasture biomass (kg/ha) at the end of the assessment period, the shortfall from the minimum pasture allowed, the number of adult equivalents that need to be destocked to preserve the pasture, the number actually available and marked for destocking based on your s and the shortfall in adult equivalents. This is only reported in months where destocking was required and so an empty report suggests no seasonal destocking was required.

This activity is performed during the Stock event of the setup and time-step events. This ensures that destocking can overrule decisions made by the herd management and mark for sale activities if needed.

The following status values apply to this activity and are shown in Activities performed report:

	blank	The activity was not considered in this time-step
	not needed	No destocking was requires
	success	Enough individuals were marked for sale to meet the required herd reduction
	partial	Individuals were marked for destocking, but not enough to meet the reduction needed. Add additional destock groups.