With the summer progressing, many farms are in the process of harvesting second-cut silage writes Brian Garry – Ruminant Nutrition Specialist, Teagasc.
Those who harvested in mid-May may already have completed the second cut. Even if second-cut silage is harvested, it is timely to take stock of fodder supplies on farms.
On many farms there now is an opportunity to put a feed reserve in place, to avoid the issues which occurred last year. The main aim should be to put a reserve of quality silage in place at lowest cost.
Some farmers may have the opportunity to harvest silage as a standing crop. The key is to be able to identify the costs of putting this silage in place.
When assessing a crop of silage there are a number of factors that come to mind. Total costs of the silage ought to be calculated and used to place a value on the silage.
Firstly, it is important to inspect the crop for yield and quality. How many bales/acre are expected?
What is the leaf to stem ratio like? What dry matter digestibility (DMD) would be expected from silage? This will allow the total UFL / ha to be calculated. Multiply the number of bales/acre by 2.47 to get bales/ ha.
Amount of silage in each bale
Next, assume, we need to work out the amount of silage in each bale. It is safe to assume that there is 200-220 kg DM in a standard round bale of silage. Where silage was wilted, there can often be in excess of 240 kg DM in a bale.
Calculate the yield in kg DM/ha, by multiplying the number of bales /ha by the amount of silage in each bale.
For example, 10 bales /acre is 24.7 bales/ha and 24.7 bales by 220 kg DM = 5430 Kg/DM/ha. Using the values from Table 1., we can put an approximation on UFL harvested per ha. For 68 DMD silage (0.76 UFL) at 5430 kg/ha, we get 4130 UFL / ha.
Producing the crop
The next task when valuing a crop is to calculate the costs incurred in producing the crop.
While there are many costs incurred when making silage, land rental, fertiliser and harvesting are the main costs.
Where land is leased, the aim should be to assign the cost of the land lease relative to the proportion of annual herbage production.
Simply, if the land is costing €200/ acre for the year, and 45% of the annual herbage grown is harvested in that cut, then 45% or €90/acre or €220/ha is the cost of the land for that cut of silage.
For fertiliser costs, use the cost/ton and the amount applied to get a value per ton. For example, a crop receiving 4 bags of CAN and 3 bags of 0:7:30 would cost €287/ ha.
Harvesting costs will vary depending on the method used. In general, bale silage is cheaper than precision chopped silage when yield is below 4000 kg DM/ha, but this can vary depending on transport costs etc.
Contractors have a guideline price of €16 plus VAT per bale for mown, baled and wrapped with four layers of plastic.
At 10 bales per acre, this works out at €160/acre or €395/ha (excluding VAT). Total cost incurred will vary depending on the management and system but will be in the region of €250 to €700/ha. This does not include feed out and ensiling losses which will be between 10 and 20% of DM yield.
Standing crop of silage
One common question that gets asked at this time of year is what price can be justified to pay for a standing crop of silage?
If we take the estimated value of the standing crop and subtract costs incurred to get the balance, this is what we can afford to pay for a standing crop. For example, a crop of silage yielding 5500 kg DM/ha with ensiling and feed-out losses of 15% will result in 4670 kg DM ha available to the animal.
If we assume silage quality is 68 DMD, each acre of grass is worth 342 standing in the field. By subtracting the harvesting costs, we get the price the farmer can afford to pay.
So, using €160/acre (excluding VAT), and transport costs of €1.5 bale, this would leave the standing crop valued at €165/acre.
Above this price and it would be more economical to purchase a concentrate rather than silage. In this situation, silage would cost €178 ton/DM or €0.23/UFL. If rolled barley can be sourced at €230/ton, it would also cost €0.23 /UFL.
When comparing feed prices, the best unit to use is the cost per UFL. This allows a direct comparison on an energy basis between feeds.
It is important to compare options available when purchasing fodder. Depending on the type of stock to be fed and the forage availability, it may be cheaper to purchase grains off the combine and store rather than a standing crop of grass of unknown quality.
There is no doubt that silage is a costly feed to produce but choosing the correct harvesting system can help minimise costs.
With second cuts are ready to be harvested is it better to use baled or pit silage to keep costs down?
Obviously, facilities, area to be harvested, farmer preference are some of the issues that influence the choice of method on farm level.
If we take a yield of 4000 kg DM/ha for second cut, this would yield 7 bales/acre. As mentioned earlier, mowing, baling and wrapping costs €16/bale (excluding VAT) so harvesting cost will be €112/acre, which is comparable to precision chop silage.
Where the yield is lower than this, it would be cheaper to use bales as the cost is lower per acre; at higher yields, it is cheaper to ensile as pit silage.
Examine all costs
In conclusion, when harvesting silage, examine all costs to calculate the cost per ton and per UFL.
It may be better value to purchase a concentrate or straights with a known quality than purchasing silage of dubious yield or quality.
Leasing land to make silage can result in very expensive feed if quality and the annual yield of grass from land is low.
Written by Brian Garry – Ruminant Nutrition Specialist, Teagasc.