Feeding Systems with Legumes to Intensify Dairy Farms - cgiar

with phosphorus at the beginning of the rains, yield, on the average, 50 to
70 g of pure seed/plant (CIAT, 1999). However, the date of the uniformity
cut affects first flowering and, as a result, the potential seed yield. Plants
cut toward the end of the rainy season or within the dry season tend to
flower little, forming few fruits.
Cratylia argentea seed does not have marked physical (due to hardness
of seed coat) or physiological dormancy, and can lose its viability relatively
quickly if it is stored under the temperature and humidity conditions
prevailing in the lowland tropics.
Nutritive Value
The usable forage of 3-month-old C. argentea (leaves + thin and tender
stems) has a CP content of 23%, but this figure varies from 19% to 26%
according to the plant’s age. Similarly, the in vitro dry matter digestibility of
C. argentea ranges between 40% and 55%, which is higher than that of
other shrub legumes adapted to acid soils, such as Codariocalyx giroides
(30%) and Flemingia macrophylla (20%). The high percentage of CP and the
low content of condensed tannins found in C. argentea make this legume an
excellent source of nitrogen for the ruminant (Wilson and Lascano, 1997).
Use and Management
Cratylia argentea has shown that it is an excellent protein supplement
in diets for dairy cows grazing poor quality grasses during the dry season.
The highest response has been from cows with medium and high dairy
potential and fed the legume as fresh and chopped or as ensiled, together
with high-energy sources such as sugarcane. For example, for Jersey cows,
as much as 66% of commercial concentrate can be replaced by C. argentea,
either fresh or ensiled, without significant loss in milk production. The
ensiled diet tends toward higher fat than does the fresh-legume diet (Romero
and Gonzalez, 2000). Similar results have been reported for dual-purpose
cows, which were offered a daily diet of 12 kg of chopped sugarcane, 6 kg of
chopped or ensiled C. argentea, and 0.6 kg of rice polishings (Table 1) (Lobo
and Acuña, 2000). Of the three supplements, fresh C. argentea was the
most economical, because of its lower costs and the cows’ significantly
higher milk production.
Cratylia argentea can also be used in direct grazing (“browsing”), with
the legume either established as a protein bank or planted in bands within
the paddocks. Experiment results showed that grazing cows having access
to a bank of C. argentea consumed more mature foliage and less immature
forage. A major advantage of this legume, therefore, is that, in direct grazing
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