The amino acid contents in grass and maize silages in the CVB Table will be updated with new research data.
From a recent study at ILVO it appears that the amino acid profile of grass and maize silage (in grams per 100 gram of crude protein) is hardly related to other silage characteristics, such as crude fiber in grass silages and dry matter or starch content in maize silages.
In 2019, Leen Vandaele, Johan De Boever and Dorien Van Wesemael analysed twelve grass silages and ten maize silages. The amino acids profile of these grass and maize silages resembled the existing values in the CVB Table quite well.
The ILVO researchers also looked at the availability of the amino acids at intestinal level. The amount of ileal digestible amino acid is calculated by adding the amount of ileal digestible rumen undegradable amino acid (dvBAA) to the amount of ileal digestible microbial amino acid (dvMAA), and subtracting the amount of ileal digestible metabolic faecal amino acid (dvMFAA). These calculations show that about 75% of the ileal digestible amino acids in grass and maize silages are provided by the microbial protein part. The production of microbial protein depends in the first place on the amount of fermentable organic matter in the rumen, therefore it remains crucial to aim for high quality grass and maize silages (with a high digestibility) for good animal performance and so for the production of less expensive roughages based milk.
The new analytical values from ILVO will be added to the database in the CVB Table.