Pastures deteriorate over time
Pastures can grow indefinitely but factors such as drought, pests, and pugging damage will cause the pasture to deteriorate over time.
- Total DM production drops
- Decline in desirable species
- Increase in weeds
- Reducing feed value
Benefits of pasture renewal include
- Increased total pasture yield (1-8 tonnes DM/ha/yr)
- Control over seasonality of production
Makes pasture management easier by using late heading varieties to minimise the drop in pasture quality as seed heads appear in late spring.
- Higher ME
New pastures produce on average 0.5-0.9 MJME/kg DM more. Reasons for this include:
- Higher proportion of desirable species
- Later and more uniform flowering
- Leafier sward, with fewer seed heads produced
- Less dead leaf material.
- Access to new endophytes
Most new perennial ryegrass cultivars are available with 'novel' (new) endophytes developed to solve particular problems in different regions.
- Animals are fed better
Cows on new pasture graze more grass, and that grass is leafier, higher in ME and more palatable. This will be reflected in:
- More milksolids production
- Faster liveweight gains
- Higher stocking rates
- More contented cows
How much pasture to renew
Replacing poor-producing pasture is profitable. It is one of the simplest ways to invest on-farm for a significant and relatively predictable rate of return.
Although the rate of pasture renewal is often set by historic practices or the budgeted levels, the most profitable rate of renewal for an individual dairy farm is best determined by an analysis of paddock performance, and from this the cost/benefit for gains through renewal.
See the select and prepare paddocks section for measures of pasture performance.