Back High drymatter maize silage

Date: 27 February 2018

Every now and again we get a season like we are currently having.  In nearly every region, high temperatures, lots of sunshine, and adequate rainfall after flowering has meant that we are looking at fields of high yielding, high quality maize silage.  Moist soils have meant that plants are still green, and the cobs are rapidly filling with starch.  In fact, many farmers will be able to take their maize to almost full starch and yet still have enough moisture in the plant to ensure great compaction and great fermentation of the harvested maize silage.

It is seasons like these where the cob (i.e. the grain) makes up a larger part of the plant’s weight.  More grain means more starch and more starch usually means more energy per kgDM.   The other impact of high grain maize silage is high dry matter maize silage.  Six years ago (2011/12) we had a similar season to this one.  Our team collected a large number of samples and the average starch, dry matter and ME per kgDM is seen in the table below.

Table 1.  2011/12 maize silage quality vs long term average

Season

DM%

NDF%

Starch %

ME (mjme/kgDM)

Long term average[1]

37.8

38.0

30.4

10.8

2011/12

39.0

34.6

33.5

11.2

The interesting thing about the 2011/12 season in table 1, is that although the average drymatter looks only slightly higher than the long-term average (39.0 vs 37.8), over 30% of the samples had dry matters over 40% and all of these also has very high starch levels.

This season, because of the reasons outlined above, it is likely that farmers will see dry matter percentages in the high 30s to early 40s. Some farmers have written into their contracts that maize silage needs to be delivered between 32-38% dry matter.  This season farmers need to be careful as to what is driving the dry matter of their maize.  If it is drought or disease, that’s one thing.  If it is because of lots of grain in their maize silage as we saw in 2011/12, then they need to be very thankful for the extra starch and the extra quality that the extra grain has brought to the maize silage they have purchased.

 

[1] Kleinmans et al, 2016. Brief Communication: Feed value in New Zealand; a review. NZSAP 2016. P 100-102