Voederbomen: een verrijking voor het rantsoen? - Praktijknetwerk ...

Summary
The possibility to use trees as landscape element, fence, fodder tree, buffer for nutrients, energy
source are searched by ‘Practise network Fodder tree’. In this research the potency of trees as
fodder tree has been researched, whereby research has been done to the nutritional value and
digestibility of trees.
The research consisted of a literature study of the factors which influence the nutritive value of
trees, the influence of tannins on the digestibility and nutritive value of trees which are able to
grow in The Netherlands. Apart from that an observation has been done on the feeding of
willow braches to goats. The nutritive values of trees were selected by good cultivate properties
of the tree, primary research, reliability of the research, edibility tree parts and the absence of
dangerous toxic compounds. Preference of goat between concentrate and willow, roughage and
willow and leave, bark and twig has been researched.
Goats are better in using trees as food source and handling of toxic secondary plant compounds.
than cows. The nutritive value of leaves is decreasing by aging. The mineral content depends on
tree species, soil type and soil circumstances. Woody plants can contain toxic compounds, but
small amounts aren’t dangerous for ruminants, generally.
Condensed tannins influence the digestibility of tree negatively and positively, through binding to
nutrients or parts of the digestive tract. Because CT influence the digestion on different parts of
the digestive tract, the digestibility of trees could only be measured by in vivo measurements.
Goats tolerate a higher concentration of tannin than cows. The effect of CT is reduced by PEG.
Only black locust and alder buckthorn have a protein content that is equal to grass. All trees have
a higher protein content than grass per kilo of fresh product. The hazel and beech meet most the
requirement of minerals of milk producing cows and goats. Protein content in leaves is as twice
as high as in twigs and lignine content in leaves is as twice as low as in twigs. The mineral content
between leave, bark en twig is different.
Trees can provide a higher milk production, meat production and fertility in dry areas and reduce
environmental pollution. Edible dry matter yield depend on fertilizing, tree, soil, climate, plant
density and cutting management. Harvest in August at a cut high of 50 – 80 cm yield the highest
edible dry matter yield.
Goat prefer willow above roughages, no preference was measured between willow and
concentrate. Goats prefer to have leaves and young parts of twigs, then bark and remainder part
of twigs. Roughages shouldn’t be fed with big amount of willow.
Fodder trees do have a potency, but more research is needed to find out if trees also makes
ruminants produce more in The Netherlands.
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