Feed Intake: Appendix A: Standard Operating Procedure Nottingham

Dry Matter Determination of Feed and Faecal Samples.

Equipment required:

1. Oven set at 80°C
2. Foil trays (ensure they are a suitable size for the sample you have)
3. Balance (PAT tested)
4. Lab coat and gloves
5. Heatproof safety gloves

Method:

1. Zero balance.
2. Weigh empty foil tray and record the weight.
3. Add your sample to the foil tray DO NOT zero the balance before adding your sample.
4. Record the weight of sample + foil.
5. For faecal samples a single tray is used for each sample and feed samples are usually dried in triplicate. This is dependent on the amount of sample you have.
6. Dry at 80°C for 5-7 days until samples are completely dry.
7. To check the dryness of samples, foil and sample should be weighed twice over two consecutive days. If the weight drops again (>0.3g) then they should be weighed a third time.
8. To calculate dry matter work out the pre and post drying sample weights by subtracting the weight of the foil tray from the weight of sample + foil.
9. Then Dry Matter = post sample weight/pre sample weight.
10. Multiply this value by 100 to get DM% and by a 1000 to get DM g/kg.
11. An average DM value can be calculated for samples run in duplicate or triplicate. If replicate values differ by >5%, repeat the determination.

Training:

Users should be supervised by a trained individual when first carrying out the procedure.