As many farmers are preparing for their first cut silage in the coming month it is important the correct preparations are in place for producing high quality forage. The quality of forage directly influences both the cow’s rumen function and overall health, as well as productivity by driving milk from home grown forage.
The Crucial Role of Cutting Date
The cutting date plays a pivotal role in determining the final quality of silage. As forage plants mature, lignin content increases, particularly in the stem, leading to higher levels of neutral detergent fibre (NDF) and lower digestibility (D-Value).
Delaying the cutting date can also result in reduced crude protein and metabolisable energy (ME) content. In fact, silage digestibility can decline by up to 3 D-value units per week from the onset of stem formation and heading. Similarly, protein content drops by approximately 3% per week. In 2024, first-cut silages have shown energy levels up to 0.6 MJ/kg DM lower than in 2023, largely due to difficult weather conditions. As a result, many farms have experienced reduced milk yields during the winter period.
Dry Matter Intake (DMI) and Forage Quality
The fibre content of silage directly affects how much forage cows can consume. For every 1% reduction in silage D-value, cows typically consume 0.2 kg less dry matter per day. This drop in intake can lead to:
- Reduced peak milk yield
- Compromised rumen function due to overly fibrous, imbalanced diets
- Increased need for high-protein concentrates
- Lower milk components (e.g., butterfat, protein)
Decreased fertility performance
Milk from Forage Increases with High-Quality Silage
High-quality forage is the cornerstone of a cow’s winter diet and is key to maximising Milk from Forage (MFF), a critical performance indicator that measures milk output from forage alone, without additional concentrate input.
High-quality forages have better digestibility, higher energy, and more protein, which lead to greater DMI. As shown in Table 1, cows offered good-quality silage can produce double the milk from forage compared to those on average-quality silage.
Table 1: The difference in forage quality on intakes and expected milk from forage.
| Average Silage | Good Silage | |
| ME (MJ/kgDM) | 10.5 | 11.5 |
| Dry matter intakes (kgDM) | 10.2 | 11.5 |
| Milk from forage (litres) | 5 | 10 |
High-quality silage leads to increased forage intakes, higher milk yields from forage, and improved animal performance, all while reducing dependence on purchased feeds. Early planning, optimal cutting timing, and correct ensiling practices are key to achieving this.
To get expert advice on improving your forage quality and maximising the feeding potential of your silage, contact your local Fane Valley Feeds representative today.
