Feeding Systems with Legumes to Intensify Dairy Farms - cgiar

Results and Discussion
The organoleptic characteristics of the silage are indicated in Table 2.
The odor ranged from slightly acetic to lactic, as evidenced by the pH values
obtained. These values correlated with lactic fermentation. As reference,
three replicates of pure soybean were fermented and their average results
were pH, 5; odor, 2; and color, 3. The high pH indicates the high buffer
capacity of legumes that can affect final fermentation results, even with as
good a substratum as maize. The use of a lactobacillus as inoculum could
improve fermentation characteristics. All silos showed an excellent
conservation of the original color.
Table 2. Odor, color, and pH of maize:soybean silage in different proportions
(Pacific Region, Costa Rica).
Treatmenta Maize:soybean ratio Odor Color pH
T1 1:1 2.50 3.00 4.25
T2 1:1 2.50 3.00 3.50
T3 1:1 3.00 3.00 3.95
T4 2:1 — — —
T5 2:1 2.50 3.00 4.00
T6 2:1 2.00 2.50 4.20
T7 3:1 2.50 3.00 3.80
T8 3:1 2.50 3.00 3.65
T9 3:1 2.75 3.00 3.68
a. Treatments are described in Table 1.
Soybean undoubtedly improves CP content, reaching almost 12% in a
mixture with equal parts of maize:soybean (w/w) in fresh basis (Table 3).
The CP content of similar silage made only of soybean was 15.6%. According
to data of the University of Wisconsin, the average CP content of 1996
samples of maize silage, collected over 10 years in Iowa and Wisconsin, was
7.6 ± 0.81% (Lauer et al., 1999). Crude protein tends to decrease with
decreasing percentage of soybean in the mixture, reaching values close to
8%. Therefore the data obtained in this experiment agree with normal values
for maize silage (7.6 ± 0.81%). The DM contents of the mixtures were very
similar and the addition of soybean had no effect, which is advantageous
because it would not reduce animal DM intake.
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