Do you know how much energy or protein is in your silage or what the actual dry matter is?

With input costs seemingly on a forever rising trajectory it is critical that farmers know these answers and feed stock accordingly this winter.

Darryl Boyd, CAFRE Senior Beef and Sheep Adviser explains the benefits of getting your silage tested now.

“It has never been as important to know what quantity and quality of forages you have on farm to minimise the need for expensive concentrate,” he said.

Whether you have a range of quality within your silages which you need to prioritise to the right groups of stock or whether you have silage which is all top quality but needs varying feed levels depending on the stock, you still need to know the facts about your silage which can only be achieved through testing.

Testing of silage in Northern Ireland during 2022 suggests good quality is out there on farms, however there are huge ranges within first cuts. D-Values have averaged 68.3 with a range of 57.9 – 76.2 and ME ranging from 9.4 – 12.2 and averaging at 11.

Research work with beef cattle in Ireland reported that every percentage increase in D-value resulted in an increase in daily carcase gain of 23 grams. Consequently a five per cent increase in D-value increased carcase gain by 115 grams per day, which is equivalent to an extra 17.25kg of carcase weight over a standard 150 day finishing period. At £4.20/kilo, that is an additional £72/carcase.

This comparison is based on concentrates at the same level of 52 per cent of total dry matter intake. The effect of high D-Value silage on cattle performance will decrease in diets with higher levels of concentrates as the silage is a smaller percentage of the animal’s total diet.

“It is clear to see the financial loss on farm of over £72/head if a farmer assumes top quality D-Value (76) when in reality it is average (68), highlighting the importance of having an analysis for your silage.”

“You may have a range of bales or pits of silage on farm, it is important to know the quality and target it to the right groups of stock.”

For example, a 650kg autumn calved suckler cow with a good milk yield may require around 120 MJ of energy per day. The same cow, only dry and 10 weeks before calving, would require less than 70 per cent of this energy.

There is no point in targeting your best silage to this dry cow. These two cows can’t be fed accurately in the same pen, therefore where cows at various stages are housed good facilities for batching are needed.

Growth is achieved when animals are fed beyond what they require for maintenance.

In terms of youngstock, SAC recently modelled the feeding of 300kg steers on poor (9.5 ME) and good (11 ME) silage fed ad-lib over 150 days.

Those on the good silage had a greater intake of 830 kilos of silage with 45 per cent of the intake used for maintenance and the remainder available for growth.

In comparison the group on the poor silage used over 70 per cent of their silage intake for maintenance leaving a lot less available for growth.

These silages require very different concentrate supplementation to ensure both groups grow at the same rate.

“Put simply you can’t manage what you don’t measure and the first measurement in feeding cattle is to know what quality your forage is.”

This can and should be done now rather than waiting to react to disappointing weight gains.

Those involved with CAFRE business development groups can speak to their adviser to have this arranged.