Overcoming one of the biggest barriers to dairy beef profits
If someone was to list the main reasons for low levels of profit in a dairy-beef system, a debate about beef sire genetics, cow type, calf price and the cost of the main inputs - such as meal, fertiliser and milk replacer - would ensue.
However, as Alan Dillion, Teagasc DairyBeef 500 Campaign Manager, explains in this article, one area that is often grossly overlooked is the impact silage quality has on the overall profitability of dairy calf to beef enterprises. This is surprising given that grass silage is a core component of the animal’s diet at some critical and costly periods. One of these periods is the finishing phase, when poor-quality silage can double the amount of meal required for the final 70-100 days of feeding.
When meal prices over the last winter hit north of €450/t, good quality silage came into its own. Taking the winter we have had, weanlings could have spent 4-5 months indoors on silage. Finishing or store cattle could have spent a similar length of time on silage also.
Remember, silage that will maintain a dry cow for the winter will not maintain a weanling or fatten a store bullock in a shed without significant concentrate input. When aiming to make top quality silage, farmers must understand the factors that affect quality.
Table 1: Factors affecting silage dry matter digestibility (DMD)
| Factor affecting DMD | Drop in DMD (%) |
|---|---|
| Lodging | 7 |
| Not grazed | 6 |
| Poor preservation | 2 |
| Stage of growth / timing of cutting | 5-25 |
Table 2: Effect of cutting date on DMD %
| DMD | 75% | 70% | 65% | 60% |
|---|---|---|---|---|
| Harvest date | May 20th | June 2nd | June 15th | June 28th |
| 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 |
At this stage of the year, fertiliser has been spread a while for first cut and really the only decision to be made on first-cut silage is when to cut the crop. The weather in the first half of May was especially bad, with constant downpours particularly in the western half of the country, so chances to take an early cut were limited.
If we want to assess how much early-cut, good-quality silage is worth to a farm, we must compare the value of the daily weight gain on good-quality silage with poor-quality silage and adjust for meal input. For this case study, we will assume a store bullock has to gain 120kg (live weight) indoors on silage and meal.
Table 3: Meal feeding levels required for various silage qualities
| Silage quality (DMD) | Daily weight gain | Meal input to achieve 0.83kg/day | Extra meal cost (144 days at €450/t) |
|---|---|---|---|
| 75 | 0.83 | 0kg | 0 |
| 65 | 0.49 | 4kg | €260 |
| 60 | 0.31 | 6kg | €390 |
For a farmer finishing 100 cattle over the winter, this would equate to a meal bill of an extra €39,000 to achieve 0.83kg/day on top-quality, mid-May cut silage versus poor-quality, late-June silage.
Good preservation
Another important variable is preservation. Grass sugars are converted to acid during the anaerobic fermentation process. This acid preserves the feed value of the crop in the sealed pit or bale. The target sugar content to ensure good fermentation is 3% or higher. This can be tested using a refractometer. Optimum conditions for high sugars are: ryegrass swards; dry and sunny weather; cool nights; and mowing in the afternoon when levels have built up. Very leafy grass has lower sugars, while wilting will help to increase dry matter content. Anaerobic conditions are essential for initial fermentation and to prevent subsequent spoilage.
Key points:
- Fill the silo quickly and roll well to exclude air.
- Chop length of 1.0-1.2cm promotes good compaction.
- Cover with 2x0.125 mm polythene sheets. Use vertical sheets along silo walls.
- Check for 3-4 days to ensure seal remains intact as the pit settles.
- Prevent bird damage.
Buffering capacity measures the resistance to a drop in pH. Crops with high buffering capacity may have a poor initial fermentation. High nitrate in grass increases buffering capacity. This can be checked using nitrate test strips. However, nitrates are of secondary importance to sugar levels. Grass will ensile correctly with up to 800ppm nitrate provided sugars are adequate. Wilting the crop to >28% DM helps to overcome effects of high nitrate.
Keep the eye on the ball
While every farmer must ensure they have adequate fodder supplies this winter - especially given that reserves are depleted following the long winter just gone by - silage quality must be to the fore of every dairy-beef farmer’s mind. Delaying cutting to increase yield is a false economy that can turn calf to beef profits down into negative territory.
This article first appeared on Agriland, as part of the Teagasc DairyBeef 500 Summer Beef Series. For more information on the DairyBeef 500 Campaign, click here.
Also read: The story so far for the Tipperary Calf to Beef Demo Farm
Also read: Ensuring the successful transition to grass with dairy-beef calves