Extensive livestock systems in toda

Extensive livestock systems in today’s Spanish dehesa
maintain a livestock stocking rate influenced at any one
time by public subsidies, a shortage of labor, and
presumably the landowner’s increasing amenity interest in
livestock (Campos, 2005). Today, over 30% of the total
energy requirements (ERs) for livestock husbandry in the
dehesa comes from supplementary livestock feed (e.g.
Campos et al., 2001, p. 52). Livestock stocking rates are
become decoupled from the dehesa’s natural forage
production and are not indicators of dehesa grazing
resource consumption. Instead, the residual estimate for
forage units extracted by livestock grazing, after other
supplementary feed (non-grazing) has been subtracted
from total ERs, is a more accurate measurement for
indicating grazing intensity. A notable feature at Haza is a
large amount of supplementary feed required, some 726
forage units per hectare of UAL (FU ha1
), which
represents 54% of total annual cattle ER. Crops, mainly
irrigated ones, contribute a considerable amount, and are
used for both grazing and as supplementary feed, so that
self-produced crops (IO) meet 37% of total cattle ER. The
GR of the monte meet 42% of total livestock ER within an
average extraction of 557 FU ha1 (Table 1). Together, the
internal feed from grazing and harvested crops grown at
Haza total a volume of 1061 FU ha1
, or some 79% of the
total annual ER of cattle (1339 FU ha1
).
An ideal oak woodland management scenario would
forcibly reduce woodland grazing access through temporary
grazing exclusion periods. It is estimated that monte
GR would in that case meet just 34% of total cattle ER
(460 FU ha1
), a decrease of 97 FU ha1
. Supplementary
fodder would rise to almost two-thirds of ER (Table 1). In
the Haza actual management scenario, the average forage
unit consumed by grazing and for supplementary feeding
costs 0.25 hFU1
. Haza’s own feeding resources cost an
average of 0.22 h FU1
, while external (bought) feeding
resources cost 0.30 h FU1
. Forage units consumed by
grazing represent the lower-cost means of delivering cattle
ER (0.14 hFU1
) (Rodrı´guez et al., 2004, p. 89). Changes
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