The time for high performing silage is now
Cutting your silage earlier, a simple change of practice on many drystock and dairy farms, can have a major impact on both animal performance and meal feeding levels next winter.
Beef finishing or weanling systems and winter milk systems are a like in one particular way, both need excellent quality silage to avoid unnecessary meal feeding in order to maximise animal performance.
Over many years of research, Teagasc has examined the relationship between silage quality and animal performance, both under beef and dairy systems. A simple conclusion from the data presented in table 1 and 2 below, where cutting date is earlier in the season and high dry matter digestibility (DMD) grass silage is produced, animal performance levels can be optimised from lower levels of concentrate input.
Table 1: Beef cattle weight gain based on silage quality
| Silage quality DMD % | 75 | 70 | 65 | 60 |
|---|---|---|---|---|
| Harvest date | 20 May | 2 June | 15 June | 28 June |
| Silage (t DM/ha) | 4.6 | 6.0 | 7.0 | 7.7 |
| Intake (kg/day) | 9.0 | 8.3 | 7.6 | 7.0 |
| Liveweight gain (kg/day) | 0.83 | 0.66 | 0.49 | 0.31 |
Table 2: Dairy cattle milk yield based on silage quality
| Concentrates (kg/cow/day) | ||||
|---|---|---|---|---|
| Silage DMD | 0 | 4 | 8 | 12 |
| 79 | 23.6 | 29.1 | 32.8 | 32.0 |
| 75 | 27.1 | 29.3 | 28.8 | |
| 69 | 24.7 | 27.3 | 30.1 | |
Why all the fuss about silage quality?
The benefits of excellent quality silage extend further than just a concentrate input saving. From a beef production perspective, higher quality silage results in better liveweight gains from finishing animals, shorter days to finish and, as a result, lower fixed costs through slurry and shed space savings. For milking cows, higher DMD silage benefits include improved forage intake, more milk solids production and milk from forage, better rumen health and of course lower concentrate feeding levels.
Some farmers often struggle with the concept of earlier silage cutting, often citing a lack of winter feed next winter as the primary concern and instead opt for a bulky first cut approach. As always, the completion of a winter feed budget for all farms is a must. However, Teagasc research shows that you are better to take two cuts, starting early to get higher total yield and better quality. Where a two-cut system, starting with the first cut in mid-to-late May, is operated, an extra 1t/ha of dry matter is produced – the equivalent of 4.5 bales/ha of silage – over and above a system where the first cut is taken on June 12.
The quality of the silage will also be far superior when cut earlier. As we move from mid-May through to mid-June, the grass plant enters its reproductive phase and throws up stem and seed heads (as evident in figure 1 below).
Figure 1: How does grass growth stage at cutting affect silage quality?
Although you are getting additional bulk in your first cut, you are bringing in a lot of poor-quality material, which offers very little nutritional value to the animal. Silage cut in early June will struggle to be 65DMD, with this worsening if the sward was not grazed before closing. Where silage swards have not been grazed prior to closing, a mid-May cutting date should be prioritised.