Explanation of Silage Terms

All values are reported on a dry mater basis, except the dry matter itself.

Dry Matter: What is left after the moisture is removed. Needed to work out the dry matter intake of the ration.
Ash: The mineral content of the silage. High values are indicative of possible soil contamination
Intake Factor: The theoretical intake of this silage assuming 6kg of concentrates are being fed. The number given is expressed per kg of metabolic bodyweight. A 625kg cow has a metabolic weight of 125kg.

Energy Supply

D Value: The digestibility of the silage, used to calculate ME
ME: The metabolisable energy – i.e., what energy the cow will actually use. A main driver for milk production and rationing models.
NDF: Neutral detergent fibre. A measure of the cellulose, hemi-cellulose and lignin in the silage. High values indicate more mature silages.
ADF: A guide to how far the seed head has travelled through the plant. This is the NDF minus the hemi-cellulose.
Lignin: The indigestible fibre portion.  High values indicate stemmier material and lower digestibility.
Sugar: The residual sugar left after fermentation. Wet silages will have lower values, dry silages higher. The bacteria in the clamp use the sugar during fermentation.
Oil: Residual oil left in the clamp.

Protein Supply

Crude Protein: The crude protein is the nitrogen in the clamp multiplied by 6.25.
NH3-N: A guide to how well the fermentation has proceeded. High values indicate butyric or secondary fermentation or significant soluble nitrogen in the crop.
MPB: The metabolisable protein from by-pass protein. See The FiMLAC Story.
MPN: The metabolisable protein based on the nitrogen in the crop. See The FiMLAC Story.
MPE: The metabolisable protein based on rumen available energy. See The FiMLAC Story.
Sn/sdm etc: The degradability coefficients used to calculate MPB/N & E

Fermentation Characteristics

pH: A measure of the acidity of the clamp. Low values may give rise to acidosis in the rumen, high values may suggest poor fermentation (depending on the clamp dry matter)
Lactic Acid: The main silage acid, needed to preserve the clamp. Too much may cause acidosis, too little may allow for secondary fermentation.
VFAs: The volatile fatty acids – butyrate, acetate and propionate. These should be lower in number than the lactic otherwise there may be secondary fermentation.
Alcohols A guide to other fermentation products.  Alcohols are mainly ethanol but other alcohols may be present.  high levels may impair rumen function.
PAL: The potential acid load. A direct measure from the NIRS giving a further guide to the likelihood of rumen problems.
RSV: The rumen stability value. Based on the PAL and NDF. In a silage, values above 260 are good. In the overall ration, it needs to be above 20.
FiMLAC Range

FiMLAC Range

Forage Analysis

Forage Analysis

Grain Exchange

Grain Exchange

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