As an aid to more accurate pasture assessment, lifetimewool has developed sets of photo standards of different pasture types and seasons. At present there are photos for annual clover based pastures(WA & SA) and High Rainfall Zone (eastern Australia) pastures in the green phase using Feed on Offer (FOO).
Hardcopy booklets of FOO photos are available for the High Rainfall and Medium Rainfall (annuals) Zones are availalbe free of charge. Contact AWI for your copy on +61 2 8295 3100 or Simon Crump at AWI.
Use these photos as a guide only. More detailed methods of assessment will give more accurate results. Feed on Offer (FOO) is measured as kilograms of dry matter per hectare. These levels include all above ground green plant matter. For those using Herbage Mass (HM) please see the conversion details provided here.
Tips for Assessment:
- Bare Ground % - has a big effect on the amount of dry matter per hectare.
- Density - it is important to feel how thick the pasture is.
- Height -usually autumn FOO is at least twice that of Spring FOO for the same amount
- Grazing Pressure - this will affect how dense the pasture is and its height. Closely grazed clover pastures can be very high in FOO for their height.
- Season - pasture moisture content rapidly changes towards flowering and senesence. This affects the weight of the pasture dramatically.
Perennial and Annual mixed pastures (High Rainfall Zone)
There are four steps involved in pasture assessment for the High Rainfall Zone.
1. Identify thepaddock the ewe mob will graze during a selected time period (10 - 30 days recommended).
Note: Where the ewe mob will be rotated through more than one paddock within this time period, an average FOO can be calculated by assessing FOO when the animals enter and leave each paddock.
eg. FOO at entry = 2000 kg, FOO at exit = 1000 kg, average FOO = 1500 kg.
2. Determine whether pasture is in 'green' or 'dry' state .
Pasture is in a 'green' state when it is in the vegetative or early flowering stage (generally from the seasonal break to sometime in spring). Once plants have entered the late flowering stage the pasture is considered to be in a 'dry' state. A pasture will switch back to a 'green' state when new plant growth commences following the break, by which time 'dry' feed reserves generally have been eaten back considerably due to grazing over summer.
With a pasture containing both 'green' and 'dry' feed, the contribution of each pasture component to ewe energy intake generally needs to be considered. However, the contribution of the 'dry' component can be ignored if 'green' FOO is greater than 1000 kg or 'dry' FOO is less than 400 kg. In this case, only the green component is considered when calculating ewe energy intake
3. Assess pasture quantity on 10 to 15 random locations across the paddock.
Use the 'FOO Photo Gallery' as a reference to make pasture quantity assessments. After recording quantity assessments, add all the values together and divide by the number of assessments to give an average pasture quantity for 'green' FOO.
These photos are at a resolution for on screen viewing. To download a hard copy of these pictures, please click on the image.
4. Evaluate pasture quality by estimating the pasture composition in paddock.
For 'Green' feed: To evaluate pasture quality of herbage in the 'green' state, the assessor needs to choose one of four pasture quality descriptions. These descriptions are summarised in the following table:
|Pasture Quality for mixed swards
||Consists of a high proportion of legumes such as sub-clover, white clover, medics or lucerne.
Grass pasture species that present are generally highly digestible perennials.
There is a very low proportion of low digestibility annuals and 'dead' pasture within the sward.
||Comprised of predominantly highly digestible perennial grass species such as ryegrass, phalaris or fescue.
Have a reasonable proportion of clover present (around 30%).
Very low amounts of 'dead' plant material in the pasture sward.
||Typically consists of a mix of highly digestible perennial grasses and moderate to low digestibility annual grass species.
The legume content of pasture species within the sward is typically low at 15%. The amount of 'dead' plant herbage generally around 20%.
||5% or less
|| Up to 50%
||Typically has a large proportion of low digestibility species (e.g. Onion grass, silver grass).
May contain a proportion of moderate digestibility species (e.g. Cocksfoot, barley grass).
Very low clover content.
May also have high levels of dead plant material in the sward.
For 'Dry' feed: As a general rule, when pasture begins to 'hay-off' (during late flowering), digestibility of feed is around 60%, depending on the pasture species present. Depending on seasonal conditions, this period may extend beyond the break into winter.
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