The quality of silage made on Irish farms is up slightly on last year, according to Farm Business Advisers (FDA) Laboratories’ Conor Butler.

After analysing approximately 50% of the expected samples this year, he said that the average Dry Matter Digestibility (DMD) of this year’s crop is 67.2%, which represents a slight increase on last year.

This also represents a significant increase on figures from earlier in the season, which put the average DMD at close to 65.6%.

He said that dry matter itself is averaging just over 25%, which is desirable in crops.

However, despite the slight increase in quality, Butler said that the most striking thing about many of this year’s samples is the high level of ammonia.

This is a direct result of cutting grass swards too early in the season before the nitrogen had a chance to be utilised properly, he said.

Further the high protein content of silage samples tested to date is a direct indication that the Nitrogen content of the grass was excessively high at cutting, he said.

Farmers find it very difficult to get the cutting date right

Butler believes that this occurred as many farmers attempted to make high quality silage from leafy swards, but he advised farmers to get grass samples analysed before ensiling in the future.

Huge variation in silage quality

Butler also noted that there is a huge range in silage quality at farm level, with DMD values starting from a very low base of 41.9% and rising to 79% for very good quality crops.

A wide range was also found when FBA carried out tests on the protein content of silage, with samples varying from 5.5% up to 19.3% on a dry matter basis.

He went on to say that average protein levels were 12.3% for this year’s crop, indicating that silage was cut from high quality grass swards.