Maize silage analyses look promising

Maize silage analyses look promising
02 Nov 2017

Initial analysis of this season’s maize silage suggest that producers will be able to look forward to feeding forage that will perform well in diets. So says Trouw Nutrition GB, which runs the UK’s largest forage analysis laboratory.

Reporting on more than 700 samples received by the company already this year, technical director John Allen says that the initial signs are encouraging. But he advises producers not to rush into clamps and give feeds a chance to ferment fully.

Growing season

“The growing season was typified by crops that struggled to mature properly and many are still in the ground,” he says. “Several samples we have seen are not yet fully fermented and will benefit from more time in the clamp before being added to rations. That said, once fed they have the potential to perform well.”

Table 1 compares this year’s initial crops with a similar sample from 2016. In all the key parameters, this year’s crops are on a par with 2016’s. Dry matter is similar at 32.9% and the ME content is also similar at 11.25MJ/kgDM. Starch is close to 30%.

Higher lignin content

“The ME. at 11.25, is consistent with early samples seen across several years. NDF content is slightly lower this year, with a higher lignin content suggesting that, despite the season, some crops were harvested at a mature stage. This is possibly because they were left in the field to allow the stem to dry out slightly more before harvest,” explains Dr Allen.

He adds that the key will be to leave crops to fully ferment and to allow starch degradability to increase as the fermentation acids break down the protein matrix, which surrounds the starch granules.

Clamp stability

“Just because you have maize in the clamp, it does not mean you should rush to include it in rations. Allowing a complete fermentation will improve feeding characteristics and clamp stability.”

Table 1: Early 2017 maize silage analysis (source TNGB)

   
2016 early samples
2017 early samples
Dry Matter
%
33.9
32.9
Crude Protein
% DM
7.3
7.4
D Value
%
72.9
71.7
ME
MJ/kgDM
11.2
11.25
pH
 
3.9
3.94
Lactic
g/kg DM
38.8
50.7
NH3-N of total N
%
5.4
5.3
Ash
% DM
3.87
3.87
Starch
% DM
30.3
29.9
NDF
% DM
40.0
36.9
ADF
% DM
22.2
19.4
Lignin
g/kgDM
24.7
34.7