Gippsland - How Now Gippy Now - September 2010 Edition
Chase quality silage this year
My time spent delivering ‘Feeding Pasture for Profit’ (FPFP) programs has reinforced my long-held belief that farmers should aim to make high quality silage. I also do this knowing full well that many influences, some under their control and many outside their control, may result in silage of lesser quality actually being harvested.
These influences could include cutting later than ideal for high quality, bad weather before or after cutting, late arrival of contractor (not always their fault), plastic not on hand at sealing time, poor management during one or several of the harvesting operations, poor final sealing, etc.
Impact of quality
Table 1 shows the impact of improving the quality of silage over a range of metabolisable energy (ME) values, looking at the response in terms of a marginal response. The example shows the difference in the value of 200 tonnes DM of silage when it is made at 11 ME instead of 9.5 ME. Assuming 8 MJ ME is needed to produce one litre of milk (which allows for some substitution, energy use for walking, body condition, etc. instead of the book value of about 5.5 MJ ME/L milk), and milk price being 25 cents/L, then the higher quality silage will result in an extra $6000 – $7000. This data is backed up by many years of research. Keep in mind that it will be tempered by changes in cow condition, level of feeding and substitution, milk production level and feed out losses.
Storage and feed out losses can be expensive
Table 1 also shows the impact of reducing storage and feed out losses from 25 per cent down to about 10 per cent. Believe me, the 25 per cent is not an exaggerated loss for many farms. The cost of losses is financially huge causing the final fed out silage or hay costs to skyrocket.
Table 1: Impact of improvements in quality or reduced losses on the
additional value of milk produced (See note below)
| Loss range |
Quality range MJ/kgDM |
|||
|---|---|---|---|---|
|
|
9.50 MJ |
10.00 MJ |
10.50 MJ |
11.00 MJ |
|
25% Loss |
$0 |
$2,344 |
$4,688 |
$7,031 |
|
20% Loss |
$2,969 |
$5,469 |
$7,969 |
$10,469 |
|
15% Loss |
$5,938 |
$8,594 |
$11,250 |
$13,906 |
|
10% Loss |
$8,906 |
$11,719 |
$14,531 |
$17,344 |
Note: Based on 200 tonne DM of fodder stored, value of milk 25 cents per litre, value
of replacement feed of $260/t DM and energy value of replacement feed of 12 MJ/kgDM. If a target quality of 11 MJ/kgDM and losses of 10 per cent are achieved there is an increase in milk income of $17344 compared to producing fodder of 9.5 MJ/kgDM with 25 per cent losses.
Harvesting high quality silage
For silage to be of high quality, pastures must be cut at grazing height which in early – mid spring is just before seed heads start to emerge and ideally, as they start to move up the reproductive tiller stem. In spring, grazing should be based on maintaining a 4–6 cm residual and grazing to be carried out just before canopy closure, which could be anywhere from the two to three leaf stage. Ideally, the pasture would be ensiled at the stage of being grazed, or very soon after, which means the paddock is back into rotation in the same round, or early in the next round.
It is too late if the sward is starting to yellow off at the base, due to dying/dead leaves and tillers, when quality will already be starting to drop off. A good, albeit too late, indicator of cutting slightly too late, is a yellow looking paddock compared to a greener shade, as seen immediately after grazing.
A major hidden advantage for high quality silage is that paddocks are removed or ‘skipped’ for silage when they are seen to be approaching canopy closure and ensiled as soon as possible after this time. This suits baled silage but I do acknowledge the problems of unpredictable weather, higher DM content targets and difficult wilting conditions. Silage additives are a big help here.
We also recommend removing or ‘banking’ paddocks from the round well ahead of grazing so that the pastures ensiled are very similar to that being grazed or can be grazed if weather turns nasty. Yes, cutting pastures at ‘Mickan length’ will result in lower yields (~1500–2000 kg DM/ha) but pasture density and quality in the silage cut areas will be maintained. More importantly pasture quality and seed head emergence is much better controlled due to maintaining grazing pressure on the remainder of the grazing area.
This scenario is of less benefit for those making pit silage because the early shut up paddocks are well past the ideal length by time of cutting, and the later shut up paddocks will usually contain more reproductive tillers with seed heads moving up/ emerging due to a lesser grazing intensity.
Yes, going for bulk will give high yields (~2500–3500 kg DM/ha) but the longer shut up period for silage, or even later cutting as hay, will result in much thinner pastures, loss of daughter tillers and lower leaves, more seed head emergence at harvest, less ground cover going into summer and less pasture production in the ensuing period. This is not even taking into account the affect of less grazing pressure on the rest of the farm also resulting in more seed head production, greater overall drop in pasture energy and protein in the late spring/early summer rotations, these impacts carrying over for several rotations.
Now try putting dollar values on the early cut silage versus later cut bulk crops taking into account these few considerations on a whole farm systems basis.
Anyone interested in doing a Feeding Pasture for Profit program in 2011, please contact Frank Mickan at DPI Ellinbank on (03) 5624 2259, frank.mickan@dpi.vic.gov.au or Bree Walshe at DPI Maffra on (03) 5147 0800 or bree.walshe@dpi.vic.gov.au.
