Interpreting pasture tests
When you receive the laboratory results, you may not immediately know what they mean. Find out how to interpret the results.
You’ll receive lab results with readings of “low”, “medium”, and “high”. These are relative to ideal levels in pasture – not the animal. Since requirements vary depending on stock class, these results need to be adequately factored in.
Consider the appropriate range of levels for your situation; regardless whether your objective is to prevent signs of deficiency, to optimise herd performance or to feed for sufficiency.
The assessment of nutritional components – energy, crude protein, fibre, sugars and starch – follows accepted standards:
- Energy is reported as MJME (Megajoules of Metabolisable Energy). Bear in mind that a sample that has been collected some time before being sent for analysis can drop in MJME.
- Crude Protein is shown as a percentage and calculated from the amount of nitrogen within the sample. Remember, this is only a crude estimate of the protein and does not distinguish between the nitrogen and the amount of true protein.
- Fibre is identified as NDF (Neutral Detergent Fibre) and ADF (Acid Detergent Fibre). To achieve optimal rumen function, ADF should be >16% and NDF should be <55% of the total diet.
- Sugars are shown as % but be mindful that values will fluctuate throughout the day. Sugar levels are naturally higher after extended exposure to sunlight, thus higher in the afternoon than in the morning.
- Starch is also shown as a %. However this is commonly very low in pasture. If results are high, this can represent the pasture going to seed.
Armed with this information you can make appropriate adjustments to your animals’ nutrition in order to achieve your objectives.