Silage sampling for analysis

Collecting a representative sample on farm is vital if the laboratory analysis is to reflect what is actually being fed. Too little attention is often paid to correct sampling methods which can lead to unjustified criticism of laboratory results. To help ensure representative samples are taken, the Forage Analytical Assurance Group has produced a recommended procedure for on farm sampling of silage. The key points are:-

1. Core samples are best used to give an early assessment of the clamp prior to feeding. - Representative samples should be made by taking 3 full depth samples from the top of the clamp along the diagonal of the clamp.

2. The face of the clamp gives a better sample of the silage the animals are actually eating. If there are area's of the face which are mouldy or damaged in any way and this material is not being eaten this should be omitted from the sample sent to the laboratory.

3. Samples (from 6 - 9" behind the face) should be taken from side to side and top to bottom following a 'W' pattern. A total of 9 - 15 samples taken along the W ensuring that each sample is taken from a different horizontal and vertical position. Avoid mouldy patches if they are not fed to the animals.

4. Samples should be thoroughly mixed and if the final sample needs to be reduced before being sent to the laboratory this should be prepared by the quartering method outlined below

• Tip the sample onto a clean surface such as a clean board or worktop. Rough concrete is not adequate!!
• Thoroughly mix the sample ensuring an even distribution of material.
• Using a clean board or card, halve the sample by dividing across the pile and separating into 2 piles. If one pile is approximately 0.5 kg, carefully place this into a clean plastic bag ensuring ALL the material in this pile is included.
• If necessary quarter the sample by dividing across the pile at right angles to the first separation to give 4 separate piles. If one pile is approximately 0.5 kg, carefully place it into a clean plastic bag ensuring ALL the material in this pile is included.
• After placing in the plastic bag, remove as much of the air as possible by squeezing the bag and seal.

Quartering is essential for all silages but particularly so for cereal and maize silages.

5. Place the sample (min 0.5kg) within at least 2 plastic bags and label clearly. Store in a fridge (not freezer) until posted to the laboratory. Try to avoid sending on a Friday as the sample will spend the weekend in transit and may deteriorate.

FAA Group
Highfield, Little London, Andover, UK SP11 6JE
email: info@faagroup.co.uk