Have you ever wondered the Importance Of Fibre does? Fibre is an energy source that is a vital component of a ruminant’s diet. It makes sure that cows chew and produce saliva which in turn makes sure that their rumen stays healthy and keeps functioning. Saliva acts as a buffer in the rumen to maintain pH levels and makes sure they don’t drop too low and cause stomach imbalances such as ruminal acidosis which can cause major declines in productivity. It is also essential in milk production in dairy cows as it is used to produce milk fat.
Two measures of dietary fibre are Neutral Detergent Fibre (NDF) and Acid Detergent Fibre (ADF). NDF is a measure of the structural or slowly digested fibrous components of the cell wall of plants such as hemicellulose, cellulose and lignin. As a plant matures the NDF level will gradually increase. A higher level of NDF will often lead to a lower feed intake and hence this value can be used as an indication of voluntary intake levels. Although a lower level of NDF is desirable it is important for NDF levels not to be too low so as to avoid stomach upsets such as acidosis.
ADF makes up a proportion of NDF levels which can be seen in Figure 1. and is a measure of the least digestible parts of a plant such as cellulose and lignin. As a rule, when ADF increases the digestibility of a feedstuff will decrease. This means that it is desirable for ADF levels to be low.
It is a good idea to know the normal NDF and ADF ranges for different forages so that you can estimate the quality and digestibility of your feed. The table below shows the different ranges of NDF and ADF levels for a variety of forages and how these levels also correspond to other important nutritional values.
CEREAL HAY/SILAGE - OATEN/WHEAT/BARLEY/Triticale
| V. POOR | POOR | AVERAGE | GOOD | EXCELLENT | |
|---|---|---|---|---|---|
| ME - Metaboliseable Energy | < 5 | 5.0-8.0 | 8-9.5y | 9.5-10.5 | 10.5+ |
| CP - Crude Protein | < 4 | 4-5.9 | 6.0-9.9 | 10.0-12.0 | 12+ |
| NDF - Neutral Detergent Fibre | 70+ | 60-70 | 54-60 | 50-54 | < 50 |
| NDF - Neutral Detergent Fibre | < 10 | 10-12.0 | 12-18.0 | 18-24.9 | > 25 |
|
RFV - Relative Feed Value |
< 80 | 80-99 | 90-100 | 101-120 | 120 + | |
|---|---|---|---|---|---|---|
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VETCH/LUCERNE HAY/SILAGE |
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| V. POOR | POOR | AVERAGE | GOOD | EXCELLENT | ||
| ME - Metaboliseable Energy | < 5 | 5.0-8.0 | 8-9.5 | 9.5-10.5 | 10.5+ | |
| CP - Crude Protein | < 12 | 12.1-15 | 15-19.5 | 19.6-22.0 | 22.1 + | |
| NDF - Neutral Detergent Fibre | 60 + | 53-60 | 41-52 | 138-41 | < 38 | |
| ADF - Acid Detergent Fibre | > 40 | 36-40 | 32-36 | 29-32 | < 29 | |
| ADF - Acid Detergent Fibre | < 9 | 9-10.9 | 11-14.9 | 15 + | ||
| RFV - Relative Feed Value | < 90 | 90-99 | 100-120 | 120-180 | 180 + | |
