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Nutritive value of Cistus salvifolius shrubs for small ruminants
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Orientador(es)
Resumo(s)
Natural grasslands play an important role in sheep production in Southern Portugal. The
increase of browse species (e.g., Cistus spp. shrubs) supplies green material to grazing animals
and can be the only source of nutrients during some periods of the year, particularly
when there is a shortage of conventional feedstuffs.
The aim of this study was to characterize leaves, flower buds and fruits from Cistus salvifolius
shrubs, harvested at different maturity stages in the Alentejo region of Portugal, by
phenological, gas production methods.
C. salvifolius shrubs presented leaves during the entire year, with a continuous increase
of leaves from November until March. Fruits were found from November to May and flower
buds were observed from April to June. Stems constituted the highest dry weight (DW40◦C;
weight after drying at 40 ◦C) proportion of the plant (545 g/kg DW40◦C), followed by the
leaves (370 g/kg DW40◦C) and reproductive organs (85 g/kg DW40◦C).
The neutral detergent fibre (NDF) and lignin (sa) contents of the leaves ranged from 267
to 350 g/kg DM and 68 to 148 g/kg DM, respectively.
Leaf CP and total phenolics levels decreased linearly with time. Linear regressions resulted
in R2 of 0.961 (P=0.00002) and 0.825 (P=0.0128), respectively. Levels in leaves and flower
bud fractions reached levels as high as 120 and 85 g/kg DM, respectively.
In the fitted models for gas production rates, the maximum rates for the November,
December, January and June harvests were approximately one half of those in February,
March, April and May.
The highest fitted levels of total leaf gas production were in November (31.66 ml/200mg
DM) and the lowest in March (13.35 ml/200mg DM). The highest fitted gas production
levels were for fruits (40.29 ml/200mg DM) and flower buds (30.74 ml/200mg DM), which
also had the lowest total phenolic contents (44.0 g/kgDM– fruits and 65.0 g/kgDM– flower
buds).
It is concluded that the use of C. salvifolius shrub (including the leaves) as a feed source for
small ruminants in the farming system when there is a shortage of conventional feedstuffs,
requires careful monitoring during the flower bud stage, when high TP levels are observed.
The potential for metabolic disorders associated with high TP levels implies that diets based
only on this shrub should be avoided
Descrição
Available at ScienceDirect
Palavras-chave
Cistus salvifolius morphological composition chemical composition ruminant gas production
Contexto Educativo
Citação
"Animal Feed Science and Technology". ISSN 0377-8401. 165 (2011) 167-175