Everything you need to know about utilising whole crop
Given the recent weather conditions there is potential in many areas to sell standing crops of cereals to livestock farmers as whole crop for ensiling.
It might be an option for livestock farmers that need to rebuild silage and forage stocks for the winter. However, the window of opportunity is short as these crops are ripening fast.
For tillage farmers the estimation of the yield in a field is difficult so there is a challenge to achieve a fair deal between both parties.
Guide to DM Content for Whole Crop and Moist Grain Harvest
Type of Crops to Use
- Use high grain yielding crops, minimum 3 tonnes per acre and preferably 4 tonnes grain / acre. A high yielding winter wheat and a high yielding spring barley crop will give similar (excellent) performance, provided grain yield is at least 50% of the total DM yield
- Poor grain yielding crops will result in poor quality whole crops with a feeding value similar to 60 DMD
- Crop yield is consistent from the soft- cheddar stage to ripening i.e. 43% to 18%
- Crops cut with a high stubble will have lower yields but higher feeding values. Crops cut with low stubble will have higher yields but lower feeding value. Grange have compared 12 cm and 29 cm stubble for winter wheat and spring barley with no difference in animal performance.
- Whole-crop wheat or barley silages should ideally be produced from crops that are between 40 - 45% DM. The target is to have at least 50% grain in a crop that has a 12 cm stubble, giving a starch content in excess of 20% of the crop DM.
- Harvesting should not take place until after the cereal grain has progressed beyond the milking-ripe growth stage. Harvest crops at the soft cheddar consistency
- Direct precision chop harvester is preferable. Mowing & picking up will lose grains
- Only crops with a DM greater than 50% require grain processing i.e. a cracker on the harvester.
- Preservation does not need an additive. An additive may be needed if the crop is cut very dry i.e. grain DM less than 30% OR if the silage is to be fed out during warm weather i.e. late spring / early autumn.
- Whole crops need to be well compacted and weighed down. A short chop length will help preservation.
- Conservation losses should be limited to a target of 12% of harvested DM, producing aerobically stable silage with negligible mould presence.
- A narrow pit is preferable.
- Lay bait around the pit
Grain to Straw Ratio
Work on the guideline that if you have a wheat crop ready to combine harvest in late August, the harvested DM yield will be about 50% grain and 50% straw (cut to ankle height) if it were modest yielding and, 60% grain and 40% straw for an exceptional crop. A good crop of winter wheat at 4 t, a ratio of 55:45 might be expected. On that basis, a winter wheat of ~4 tonnes grain/acre is good and thus that as a whole crop it would have yielded about 3.2t grain DM + 2.6t straw DM = 5.8t harvested DM per acre or 5.1 t utilisable DM (losses assumed to be 12.5%).
Valuing the Crop
Estimate Grain Yield by Experience or Other Crops Harvested on the Farm or Harvest a strip of grain off the field, weigh it and measure the area harvested. Based on the harvested yield, extrapolate out the total yield of grain per acre and the whole crop yields based on the ratios above and calculations in (2) below.