pastures and livestock

A rangeland or pasture that has warm- and cool-season species has a
longer season of green vegetation than if only one of these classes is
present. High-quality, nutritious forage is available throughout the growing
season with a mixture of cool- and warm-season species. If only cool-season
species are present, these species are the most nutritious during spring and
possibly again during late summer or fall if regrowth occurs.
There usually is a period during midsummer when cool-season grasses are
less palatable because of stemmy reproductive structures and older leaf material.
On the other hand, a pasture that contains primarily warm-season grasses does
 not provide very nutritious forage in early spring because these grasses grow better
during late spring through midsummer.
Different growth habits and requirements of cool- and warm- season species can be
used to your advantage in a grazing program. For example, you may want to establish
cool-season grasses in tame pastures to use in early spring or fall when these species
are most nutritious.
Livestock can rotate to pastures with warm-season species during late spring and summer.
For ruminant to survive, a pasture is needed. Save a grassland for your animal's to supply
You the best. In terms of meat, milk etc.