The high cost of ownership and maintenance of the specialized machinery required for forage production, which is used only for a short period of time during the year, has increased the amount of silage produced by custom harvesters.
Because of their focus on harvesting forages for their client base, professional custom harvesters keep up to date with machinery developments and can hone the skills necessary to ensure that forage crops are harvested at the correct maturity and dry-matter level. Running modern, high-capacity machinery, they can fill silos quickly and ensure a tight pack, resulting in high-quality stored feeds.
One issue to address is the timely availability of custom harvesters, especially when growing conditions may narrow the harvest window.
Hiring a custom harvester may decrease the control of the producer over the timing of the harvest operations. If a decision is made to use the services of a custom operator, be prepared to spend some time searching for and interviewing candidates. Check references as appropriate.
The topic of most controversy is how the custom harvesters should charge for their services. There are several ways to charge, e.g. by area harvested, by time and by the mass harvested. The custom harvester has to swath (if appropriate), chop, haul and pack the forage.
Charging by area is not an advantage for the harvester if the yield is high and if the field is small or inefficient to harvest, because of shape, location, topography, etc.
The use of aggressive processing increases the overall machine power requirements by 8 percent and penalizes the time required for the job by at least 15 percent.
Paying by the hour might increase tension between harvester and customer, as the latter may be inclined to feel that the job is being done too slowly.
When charging by weight it is essential that there is an accurate, calibrated scale available, either with a fixed system at the facility or through a mobile weighing system.
Paying on the dry matter tonnage harvested could be viewed as the ideal method: the dairy ration is formulated on a dry matter basis and so this would give the dairy producer the most direct control over the input costs for his forages, subject to adjustment for losses.
However, this could encourage the harvester to push the crop to higher dry matter levels, with the possible result of dry matter levels being outside the optimum range. Target DM levels depend on the type of storage system, additives used and the forage crop harvested.
Custom harvesting corn typically costs around $8 per ton. In practice a producer would also need to include the additional costs to apply a preservative (~ $0.25 per ton) and for hauling (~ $0.15 per mile), and bagging costs (~ $5 per ton) as appropriate, which will not be added in this example.
At 35 percent DM, $8 per ton corresponds to $8 per 750 pounds of forage on a dry-matter basis (2000 lbs × 0.35 t DM); thus the cost of the job per pound of DM would be $0.0113 ($8 / 750 lb DM), or $22.60 per ton DM.
If the corn was harvested at 30 percent of DM, the cost per pound of DM would be $0.0142, or $28.40 per ton DM. Clearly, this “dilution effect” has to be taken into account, since the cost of the nutrients would increase.
However, even as we consider making adjustments for the DM level in the crop harvested, we also need to look at controlling the quality of the crop at harvest.
This is the ultimate determinant of the final quality of the feed as fed: everything else we do in silage management is targeted at retaining as much of the quality harvested as possible.
For example, for corn silage we need to consider the relationship between kernel maturity, silage yield and quality.
Milk production per acre is 35 percent less when corn is harvested at the immature soft dough stage (24 percent DM) compared to the optimum stage at 50 percent kernel milk (34 percent DM). Milk production potential is reduced when immature corn is harvested for silage; production is lost, left in the field.
On the other hand, if the corn crop is harvested at too advanced a stage of maturity and consequently higher level of DM, the forage will have low fiber and starch digestibility, be difficult to pack and most likely will have issues with aerobic stability, all leading to significant production losses.
For corn crops over 30 percent dry matter, kernel processing becomes increasingly important, and so the degree of processing should be tracked.
If the forage in question is a legume, harvest charges can be adjusted based on the quality level (RFV) of the material, a generally recognized standard measure.
For instance, an agreed price per ton of DM haylage at RFV of 140 to 160 can be reduced by $1 per point of RFV for haylage testing less than 140 RFV, and increased by a premium of the same number for haylage testing greater than 160 RFV.
An alfalfa crop can quickly lose up to 5 points in RFV after it passes its prime. A more accurate alternative for quality evaluation, particularly for grasses, is RFQ, which accounts for variations on the digestibility of the fiber portion.
Thus, the ideal approach would be to have a pre-harvest meeting of all the necessary parties involved, including the nutritionist/feed adviser, feed manager, dairy owner/manager, and crops manager/agronomist.
This meeting should generate a written contract detailing the agreed targets for all the parameters to be managed and/or monitored during the harvest, and can include potential penalties if any requirement is not accomplished.
Of course, there may also be a need to build in allowances for changes in conditions outside of control (e.g. weather) that can fundamentally affect the targets set. Among the key targets to discuss, agree and control are:
- Plant maturity/stage of growth (consider RFV/RFQ for haylages)
- Chop length
- Degree of kernel processing achieved (if appropriate to crop)
- Crop dry matter at harvest
- Packing density (during harvest)
The key is to agree on the targets, and then to keep communicating clearly and frequently, to minimize unnecessary disappointments and misunderstandings. FG
Robert Charley and Renato Schmidt for Progressive Forage Grower
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Robert Charley |
