Most Irish farmers are feeding silage to their herds this winter without knowing what’s actually in it. In last year’s Teagasc Fodder Survey, only 30% of farmers said they intended to test the quality of their silage. That’s a costly blind spot. Poor-quality silage silently drains milk yields, weight gain, and fertility all winter long, and by the time you notice, the damage is already done.
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Why This Year’s Silage Needs Checking
A difficult spring pushed back first-cut dates on many farms. Drought conditions through the summer are now delaying second and third cuts too. Both factors point in the same direction: silage quality could be lower than usual in many yards this year.
Cutting date is the single biggest driver of silage quality. Once a sward’s seed heads emerge, dry matter digestibility (DMD) starts dropping by roughly a point every two to three days. A two-week delay can turn an excellent cut into an average one.
Teagasc reports that the national average silage DMD remains in the mid-60s, suitable only for dry cows in good condition. Growing and finishing stock, and milking cows, need silage well above that to perform properly. Without a test, you’re guessing which category your silage falls into.
What Silage Testing Actually Tells You
A silage test replaces guesswork with numbers. Southern Scientific’s grass and silage testing service covers the parameters that determine feed value and preservation quality:
- DMD (dry matter digestibility) – the core measure of energy value. Dry cow silage should sit between 68-70%; milking cows and growing stock need 74% or higher.
- UFL (energy) – dry cow silage should read 0.72-0.75 UFL/kg; milking cow silage needs 0.83-0.88 UFL/kg.
- Crude protein – over 12% for dry cows, over 14% for milking cows. Protein levels track closely with DMD and nitrogen timing at application.
- PDIE (digestible protein) – 75g/kg for dry cows, over 80g/kg for milking cows.
- Potassium (K) – should stay under 2.2% for dry cows, since high-K silage fed close to calving raises the risk of milk fever.
- pH, ammonia, and lactic acid – these flag how well the silage was preserved. A pH between 4.0-4.2, ammonia below 8% nitrogen, and lactic acid between 8-10% DM all point to stable, palatable silage.
The Cost of Skipping the Test
The numbers make the case on their own. Teagasc research shows that feeding 75% DMD silage instead of 65% DMD silage adds around 40kg of extra liveweight gain over a 150-day housing period, or cuts concentrate needs by 2-2.5kg a day.
Feed conversion tells the same story from a different angle. It takes roughly 17kg of dry matter from 75% DMD silage to put on 1kg of carcass weight, against 46kg of dry matter from 60% DMD silage to achieve the same gain. Lower-quality silage doesn’t just underperform; it costs far more to feed.
Silage testing costs a fraction of that difference. Skipping it means feeding blind through the most expensive months of the year, and either overfeeding concentrates to compensate or underfeeding animals that need more.
Building a Fodder Budget That Actually Works
Testing silage quality is only half the picture. Pairing it with a fodder budget tells you both how much feed you have and how good it is. In last year’s Fodder Survey, 90% of farms expected adequate winter supplies, but roughly 5% were heading for feed deficits of 20% or more, and only 40% of farms had completed a fodder budget at all.
Getting a test done now, while the crop is fresh, gives you time to act on the results. That might mean buying in additional fodder, adjusting concentrate rates, or targeting your best-quality bales at the stock that need them most.
Get Your Silage Tested With Southern Scientific
Southern Scientific runs silage and grass testing from ISO 17025 accredited labs, with results on silage and grass samples turned around in 24 hours. Testing covers DMD, energy, protein, and mineral content across grass silage, maize silage, and whole crop suites, giving you a clear feeding plan before the housing season starts.
Regular silage testing is part of moving from reactive crisis management to proactive protection when it comes to herd performance and winter feed costs. Don’t wait until animals are underperforming to find out why.
