The first step in determining the feed supply is to construct a pasture supply curve and assess the variability between years. This requires knowledge of the annual rainfall and its variability, temperature patterns and pasture types.
To review the annual rainfall pattern, graph the average, long-term rainfall figures, or to find long-term rainfall information, visit the Bureau of Meteorology (BOM) Climate Data Online website.
Total farm feed supply determines how well an enterprise and stocking rate will suit the growing season. On any farm there may be a range of pasture and feed sources that can provide forage at different times of the year. In addition to total feed volume (i.e. pasture growth), consider pasture quality at different times of the year.
There are several methods available to determine annual pasture growth patterns for key pastures species:
- Pasture growth data can be entered into the MLA Feed Demand Calculator to generate an overall supply curve for any given location. The MLA Feed Demand Calculator can be used to trial different stocking rates, lambing times and determine pasture deficits or surpluses.
- Using the Daily pasture growth estimates tool, manually work out the average pasture growth each month This is relatively easy where there are only 2–3 common types of pasture.
- Local state agency staff or agronomists can advise on usual pasture growth patterns for the region.
- Use tools, such as the computer model GrassGro®, to get more specific data for pasture species, soil types and soil fertility levels and how changes to these will influence pasture growth and quality.