TheImprovement ofTropical and Subtropical Rangelands

GRAZING MANAGEMENT
IS5
a more nutritious diet than does a dry animal. If the herd is largely
in the lactation production phase or, conversely, in the maintenance
phase of the animal production cycle, the needs for nutrients from
rangeland can be reasonably estimated. Herds that consist of growing,
dry, and lactating animals should be fed according to the needs of
the growing animals, unl.- special supplementation can be provided
to those with the greatest nutrient demand. It is generally agreed
that the animals with highest nutrient demand set the base nutritional
requirement of the herd. In tropical and subtropical countries,
however, the demand for quantity of forage is so great that little
attention is paid to quality. A range manager who can find a way
to upgrade the diet quality in growing or lactating animals could
greatly increase productivity.
The range probably cannot provide the quantity or balance of
nutrients during the entire year. If animals are fed when rangeland
forage is deficient, then a grazing program should be developed to
complement the feeding period. It may be necessary to provide only
a portion of the nutrients during part of the year, ad feeding can
be replaced with supplementation that can bring the animal's nutritional
level up to minimum requirements. Supplementation will be
less costly than feeding and, when correctly used, will provide for
excellent livestock performance on ranges that without supplementation
cannot meet the minimal needs of the livestock. Supplements
can be worth many times their cost since they add what is needed
to provide a correctly balanced diet, but IUpplementation is not a
normal practice in most countries because of the comparatively high
coet ofdesirable supplements. Furthermore, in remote areu, the COlt
of transportation of supplements to the herda is often prohibitive.
Since rangelanda by their nature exist in area with variable
and extreme climates, a grazing program must have some plans for
the expected but unpredictable droughts or storms. Forage ~rv.
can be of utmOlt importance over the long term. Excellent use of
shrubs and cacti is being made in many countries where the grazing
demands exceed supply in extreme years. Forage reserv. can prevent
catastrophic losses ifthey are predictably planned for and used (fipre
6-11). Although some UI8 of forage rel8rv. during normal years
may be appropriate, it is critical that they be sufficient to ameliorate
the forage loeses that are sure to come to the Bemiarid and arid
rangelands during drought. Many forage reserv. are considered a
luxury, since in many countries demand exceeds supply of forage in
normal years. The hems system of North Africa and the Middle East