Sheep & Cattle Carrying Capacity
Godolphin is typical of a property in the High Rainfall Zone of Australia. Properties are smaller than those further west but have a higher carrying capacity. At around 850 metres altitude reflecting its proximity to the not long extinct volcano of Mt. Canobolas to the west, Godolphin has cold wet winters and relatively mild summers.
Our estimate of carrying capacity before “Super and Sub” began in earnest in the 1950’s, is around 1-2 DSE/acre (or 2-5 DSE/ha in metric units). Within perhaps five years of the program starting the levels had increased, initially to perhaps 20 DSE/ha due to the sudden increase in soil nitrogen from the newly sown clovers. Within a few years as the new grasses regained dominance over, and then equilibrium with, the legumes it settled back to current levels of around 10-14 DSE/ha.
The monthly figures for years 2006 to 2013 are shown in the image below.
There is a clear pattern of reduced stocking rate in winter months as about a third (5-6 DSE) of the stock are sold each year. The numbers increase naturally again in the Spring. The chart in the image below also shows how the lower winter stocking rates shown in the chart above reflect the depressed the pasture growth in winter. (The surrounding images also give a visual representation of how the feed supply can vary from time to time).
The proportion of sheep versus cattle has been fairly steady in this period as seen in the following chart.
Cattle suffer more than sheep in a drought as they cannot crop any available grass as closely due to their larger mouth. Conversely they do better than sheep when the grass becomes long and coarser. Their gestation period is longer ( 9 months compared to 5 months) and fecundity ( 90-100%) is less than the sheep (110-180%) and usually mean returns for sheep are higher unless there is a disproportionate change in the price of beef and lamb. On the other hand sheep husbandry can be more intensive and expensive.