Forage analysis is a tool used in order to formulate balanced rations so that animal performance is maximised at lowest feed cost. It is also important in assessing how good is your forage management and to further improve any areas that aren't so well managed to help reduce requirement for costly supplementation for next year's crop.
It is crucial to execute forage analysis before buying any other feedstuffs. With that being said, the analysis results are only as good as the sample collected. Therefore, make sure you collect a representative sample. Different labs will have different requirements. It is best to check with them first.
Interpreting the analysis
Routine silage testing is now done through Near Infrared Reflectance Spectroscopy (NIRS). For unusual silage mixture, it will be analysed using wet chemistry methods. Key results to look out for:
Dry Matter (DM) - Most analysis results are expressed as a % of DM. Therefore, it is important to know the amount of dry matter in your silage. This information will also affect the interpretation of other results. For example, wet silage needs to have a lower pH in order to have a good preservation than higher DM silages. If only one forage is being fed to the animals, then the DM will play a significant role on total diet intake.
pH - pH measures the acidity of the silage and is one of the most important indicators regarding the quality of silage as it shows how well the fermentation has been. Good fermentation will produce lactic acid, which will reduce the pH faster to a lower stable final pH. Recommended pH is around 4.5 as that is the pH required to stop the activity of most spoilage organisms and produce stable silage. For wetter silages, pH needs to be around 3.7 - 4.3 in order to prevent activity of spoilage organisms.