Most dairy farmers in Northern Ireland will have sufficient silage stocks built up by this stage to get them through the coming winter, according to United Feeds nutritionist, Matt Bourne.

“The GrassCheck figures indicate that there was sufficient grass growth achieved up to this point to allow farmers make the quantities of silage they need,” he commented.

“The decent spell of weather in September was a genuine boost in this regard.

“In addition, an increasing number of milk producers throughout Northern Ireland are strategically committing to a four-cut silage regime.

“A survey carried out in 2021 confirmed that a four-cut silage system, when incorporated into a TMR [total mixed ration] feeding regime, relative to a three-cut option, improved the gross margin achieved by 32p/cow/day.

“The actual figures recorded were £5.50 and £5.18/head,” he explained.

Silage quality in Northern Ireland

The United Feeds nutritionist went on to confirm a significant variation in the quality of silages made in Northern Ireland this year.

He also pointed to a new ‘ash’ category within the quality criteria referenced in the silage analysis reports received by farmers this year.

According to Bourne, this is a development that has been specifically requested by farmers.

“The ‘ash’ value refers to the total mineral content of the forage analysed. The figure relates to the grams of ash per kg of forage on a dry matter basis,” he explained.

“So a value of 89 relates to an ‘ash’ value of 89g/kg of forage dry matter, or 8.9%.

“The threshold value that farmers should be mindful of is 90. Figures above this level would indicate that the silages submitted contain relatively high levels of soil contamination.”

Analysis

The United Feeds nutritionist also pointed out that high levels of soil in silages can increase the risk of mycotoxins contamination.

“Many mycotoxins are totally invisible to the naked eye,” he commented.

“The confirmation of high values in a silage would be a clear indicator of adding a mycoxtin binder within rations fed to cows and other stock.”

United Feeds has now analysed a significant number of first- and second-cut silages made throughout Northern Ireland in 2023.

On average, first-cut dry matters are up compared with 2022 – 28.0% versus 24.6%. Meanwhile,  pH values have remained pretty constant – 4.1 in 2023 compared with 4.0 in 2022.

The same principle holds where ME (metabolisable energy) values are concerned – 10.9 in 2023 versus 10.8 last year. Average D-values in 2023 are coming in at 66.5. The equivalent value for the previous year was 65.5.

Lactic acid values were no different, year-on-year. The figure has remained the same at 8.5.

However, there have been significant differences in a number of other quality criteria between 2022 and 2023.

Intake values have risen from 91 last year to 97.1 in 2023 while NDF (fibre in silage) values have fallen back from 53.6 in 2022 to 49.4 this year.

Matt Bourne has specifically highlighted the year-on-year differences in crude protein values.

“Crude protein values for this year’s first-cut silages are averaging 14.6. The equivalent figure for 2022 was 13.2,” he said.

“In addition, free ammonia values have dropped during the same period, from 7.7 in 2022 to 4.91 this year.

“Taken together, these trends point to the possibility of farmers feeding less protein in the concentrate fraction of dairy cow rations over the coming months.”