Marloth Park Management Plan. - Nkomazi Local Municipality

SUPPLEMENTARY FEEDING
The main objective of supplementary feeding is to supplement deficiencies, as well as to
stimulate the appetite of the grazing animals to ensure better utilisation of poor quality foraging
material. It is common for certain areas to have deficiencies in minerals and these deficiencies
can affect animal productivity. Originally game was able to move freely over large areas to select
the most nutritious food, but due to the animals being restricted by fences it has become
necessary to provide supplements.
The nutritional value of grass species, particularly in the Sourveld regions, decreases
considerably as the grass matures, especially in autumn and winter. This is associated with the
deterioration in the condition of the animals.
DIGESTIBILITY
The digestibility of the organic matter is one of the main factors determining the nutritive value
of forage. A high digestibility is maintained in the spring and this declines as the plant matures
over the summer due to changes in the chemical composition of the plant. The rate of this
decline varies between grass species.
The basic determinant of forage digestibility is the plant anatomy. Plant cell contents, being
mainly carbohydrates and proteins, are almost completely digestible, but cell walls vary in
digestibility according to their degree of reinforcement with lignin. As plants grow there is a
greater need for fibrous tissues and therefore the main structural carbohydrates and lignin
increase. However, the concentration of protein decreases as the plant ages. Thus digestibility
decreases as plants increase in maturity. There is a reciprocal relationship between the protein
and fibre contents in a given species.
PROTEIN CONTENT
Protein is most probably the most common chemical component that limits animal performance,
provided sufficient energy is supplied. Protein requirements of animals depend on the species
and class of animal and on the level of production.
A minimum figure of 5 percent crude protein in natural pastures is generally required for
ungulates on African veld, whereas 8 percent crude protein is necessary in the vegetation for
livestock. This indicates that game can cope better than livestock in poorer veld conditions.
Protein content varies among different forage species and generally declines with maturity. In
general the leaves of trees and shrubs seasonally provide a more constant and higher level of
protein than the grasses.
© Ecological Associates/ Marloth Park 81