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With the consumption of dry feeds or senesced forages in dryland systems, a
greater proportion of water requirements must be met from drinking water. In fact,
feed quality and availability affect the frequency with which animals visit watering
points (Squires 1981 ). Similarly, the quality of the ground water, especially its salt
content, can affect their water intake as well as their food intake. Animals fed a high
salt content diet can reduce their feed intake by over 35 % (Blache et al. 2007 ). To
mitigate the dependency of ruminants on water, pastoralists must offer water points
across the landscape that is to be used for grazing, and then depend on the animals
finding and remembering the locations, or else the producers must herd their live-
stock to the water points (Squires 1981 ).
A carefully planned distribution of water points is essential because the animals
need to balance the distance walked to water and the distance walked to find food. In
many situations, feed supply near water points is low because of high grazing pres-
sure in these locations, and because animals choose to camp near water, especially in
hot conditions. This behaviour limits use of biomass (Holechek 1997 ). In rangeland
situations, maintenance of water points can be costly and, with free- ranging animals,
the monitoring of water points is essential to maintain productivity.
3.3 Management of Heat Stress
Exposure to high temperature or solar radiation can induce heat stress, reducing
both welfare and production (Silanikove 2000 ). In addition to access to enough
water, shade should be provided to encourage behaviours that decrease the inci-
dence of heat stress. On hot sunny days, ruminants seek shade from trees, or even
from their peers, and will increase their water intake if the water points are not too
far from where they spend most of their time. The ability to cope with high tempera-
ture varies with breed – for example, the evaporative critical temperature (i.e., the
temperature above which the animal starts using evaporative heat loss mechanisms
to maintain its body temperature constant) varies between the Jersey (24°C) and the
Brahman (35°C; MacFarlane 1968 ). Regardless of the genotype used in the produc-
tion system, providing shade and shelter should be an essential component of any
integrative and versatile system (discussed further in Section 4).
Management of stocking density is an alternative to managing feed on offer or
increasing supplementation when feed demand exceeds feed supply. Management
of the stocking density also affects the flow rate required to maintain an adequate
supply of water to a group of animals. There are two types of strategy: i) stocking
density managed on a long term scheme (‘long-term carrying capacity’, LTCC); ii)
stock numbers adjusted according to the seasonal availability of food on offer (‘vari-
able stocking’). Both strategies have been reviewed recently and discussed in the
context of northern Australian rangeland (O’Reagain and Scanlan 2013 ). Briefly,
LTCC is a safe strategy designed to use 10–30 % of the annual pasture growth
(Scanlan et al. 1994 ; McKeon et al. 2009 ). A recent computer simulation suggests
that limiting the degree of flexibility in stocking density would enhance sustainabil-
D. Blache et al.