Table 5 reports the chemical composition of five components from corn. The level of starch in grain was not as high as expected (50-60% is typical), perhaps because of the crop’s late maturity. Fiber concentrations, either ADF or NDF, are good indicators to estimate the proportion of grain and stover in a whole-plant mix.
Table 6 shows the chemical composition of components after water separation. The sunk grain had a level of starch as expected but more fiber than expected. The sunk stover probably contained small fractions of grain that could not be separated manually. The suspended and floating materials also probably contained some small grain particles that had not sunk after the first water separation. The effluent DM containing soluble and very fine particles had on average 26% starch and 3% ADF, indicating a larger proportion of grain than stover components. Prior to water separation, silages in experiment 2 had an average composition of 8.5% CP, 19.1% starch, 23.6% ADF, and 40.3% NDF.
 |
|
Table 5
Chemical Composition on DM Basis of Mature Whole-Plant Corn Components*
|
Component
|
CP (%)
|
P (%)
|
Ca (%)
|
K (%)
|
Mg (%)
|
Starch (%)
|
ADF (%)
|
NDF (%)
|
|
Grain
|
4.9 b
|
0.25 a
|
0.03 d
|
0.31 d
|
0.11 d
|
42.5a
|
2.5 d
|
21.0 d
|
|
Stalk
|
3.3 c
|
0.10 bc
|
0.16 b
|
1.04 a
|
0.17 b
|
0.4b
|
45.5 b
|
78.3 c
|
|
Husk
|
3.9 c
|
0.07 cd
|
0.13 c
|
0.74 b
|
0.16 c
|
1.3b
|
42.2 c
|
84.4 b
|
|
Cob
|
2.8 d
|
0.05 d
|
0.05 d
|
0.60 c
|
0.08 e
|
0.1b
|
44.5 b
|
90.6 a
|
|
Leaf
|
5.7 a
|
0.13 b
|
0.44 a
|
0.23 d
|
0.25 a
|
1.3b
|
46.8 a
|
77.8 c
|
|
SEM
|
0.3
|
0.02
|
0.01
|
0.05
|
0.01
|
2.3
|
0.8
|
2.7
|
|
LSD
|
0.7
|
0.03
|
0.02
|
0.12
|
0.01
|
5.2
|
1.8
|
6.1
|
* Average of three replications. Values with the same superscript letter in a given column indicate no significant difference (p < 0.05). SEM, standard error of means; LSD, least significant difference.
|
|
 |
 |
|
Table 6
Chemical Composition on DM Basis of Corn Silage Components After One or Eight Water Separations*
|
Component
|
CP (%)
|
P (%)
|
Ca (%)
|
K (%)
|
Mg (%)
|
Starch (%)
|
ADF (%)
|
NDF (%)
|
|
After one water separation (experiment 3)
|
|
Sunk grain
|
1.9 d
|
0.06 a
|
0.02 a
|
0.15 a
|
0.03 d
|
55.0 a
|
5.3 c
|
16.9 a
|
|
Sunk stover
|
4.0 c
|
0.10 b
|
0.07 b
|
0.22 b
|
0.07 c
|
16.7 b
|
29.7 b
|
50.9 b
|
|
Suspended stover
|
5.1 b
|
0.11 b
|
0.18 a
|
0.23 b
|
0.09 b
|
6.8 d
|
39.0 a
|
63.4 a
|
|
Floating material
|
6.0 a
|
0.16 a
|
0.18 a
|
0.38 a
|
0.14 a
|
9.5 c
|
36.5 a
|
61.5 a
|
|
SEM
|
0.1
|
0.01
|
0.01
|
0.01
|
0.00
|
1.2
|
1.6
|
2.2
|
|
LSD
|
0.3
|
0.02
|
0.02
|
0.03
|
0.01
|
2.7
|
3.6
|
5.1
|
|
After eighth water separation (experiment 2)
|
|
Effluent DM
|
15.5
|
0.64
|
0.95
|
3.13
|
0.73
|
25.9
|
3.2
|
5.0
|
‘Average of three replications after one separation, average of 12 replications after eighth separation. Values with the same superscript letter in a given column indicate no significant difference (p < 0.05). SEM, standard error of means; LSD, least significant difference.
|
|
