Nutritive value and microbiological quality of maize silages
Ueli Wyss1and Pierre Aeby2
1Agroscope Liebefeld-Posieux Research Station ALP, 1725 Posieux, Switzerland
2Agricultural Institute Grangeneuve IAG, 1725 Posieux, Switzerland
Conclusions
The investigation showed that the density in the maize silages is a problem in bunker and in tower silos in commercial farms. As the yeasts are mainly responsible for the aerobic instability, their concentration must be reduced.
Introduction
Maize is a plant which is easy to ensile. In commercial farms, there are often problems with aerobic deterioration during feed-out. The nutritive value, the microbiological quality as well as the aerobic stability of 22 maize silages collected from Swiss farms, who participated at a little champion- ship, were investigated.
Materials and Methods
The samples were taken with a core sampler in six places in the silos. Half of the silages were treated with a silage additive. Besides the density, also the nutritive values, the yeasts and mould content as well as the aerobic stability were investigated. The nutritive values were calculated according to the equations published by ALP.
Results and discussion
The average density was low with 185 kg DM/m3. The mean values between bunker and tower silos were similar (Table 1).
The pH-values were, with an average of 3.8, relatively low and according to a sensory appreciation the silages were of good quality. Big differences between the samples were found as far as yeasts and moulds are concerned. The silages heated up after 76 h on average.
The aerobic stability of the maize silages depends very strongly from the yeasts content (Figure 1). In this investigation no relation between the density and the aerobic stability was found (Figure 2).
Table 1. Density, dry matter content, nutritive value, microbiological quality
(averages of 22 silages, 11 tower silos, 10 bunker silos)
DM: dry matter; FM fresh matter; SD: Standard deviation;
NEL: Net energy for lactation; cfu: colony forming units.
Figure 1. Relation between the aerobic stability and the yeasts
y = 23.062x-0.3918 R2 = 0.62
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0
0 24 48 72 96 120 144 168 192 216 240
aerobic stability, h
yeasts, log cfu/g
y = 0.0196x + 182.7 R2 = 0.0017
140 160 180 200 220 240 260 280 300
0 24 48 72 96 120 144 168 192 216 240
aerobic stability, h
density, kg DM/m3
Figure 2. Relation between the aerobic stability and the density
mean SD minimum maximum
bunker tower
Density, kg DM/m3 185 29 151 278 181 189
Dry matter , % 32.3 3.8 26.1 43.2 30.7 33.5
Ash, g/kg DM 34 4 26 41 35 33
Crude protein, g/kg DM 71 7 51 84 71 70
Crude fibre, g/kg DM 202 21 154 251 203 200
NEL, MJ/kg DM 6.3 0.2 6.0 6.7 6.3 6.3
pH 3.8 0.1 3.6 4.0 3.8 3.8
Yeast, log cfu/g FM 4.6 1.5 2.1 7.1 4.2 4.9
Mould, log cfu/g FM 2.2 1.3 1.0 6.6 2.4 2.2
Aerobic stability, h 76 61 19 219 82 63
type of silo
XVthInternational Silage Conference, July 27-29 2009, Madison, Wisconsin, USA
