Browsing by Author "sohil Boufennara"

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    Chemical composition and digestibility of some browse plant species collected from Algerian arid rangelands
    (Spanish Journal of Agricultural Research, 2012) sohil Boufennara; Lyas Bouazza
    Many wild browse and bush species are undervalued mainly because of insufficient knowledge about their potential feeding value. The objective was to evaluate some nutritional attributes of various Algerian browse and shub species (Atriplex halimus, Artemisia campestris, Artemisia herba-alba, Astragalus gombiformis, Calobota saharae, Retama raetam, Stipagrostis pungens, Lygeum spartum and Stipa tenacissima). Chemical composition, phenols and tannins concentration, in vitro digestibility, in vitro gas production kinetics and in vitro bio-assay for assessment of tannins using buffered rumen fluid, and in situ disappearence of the edible parts of the plants (leaves, thin twigs and flowers) were determined. In general, protein content in dicotyledon species was always greater than in monocotyledon grasses, these showing higher neutral and acid detergent fibre and lower lignin contents than dicots. The tannin concentrations varied considerably between species, but in general the plants investigated in this study had low tannin contents (except for Artemisia spp. and S. tenacissima). Monocots showed lower in vitro and in situ digestibilities, fermentation rate, cumulative gas production and extent of degradation than dicot species. The plants were clustered by principal components analysis in two groups: poor-quality grasses and the most digestible dicot species. Chemical composition (neutral detergent fibre and protein) and digestibility were the main influential variables determining the ranking. In conclusion, A. halimus, A. campestris, A. herba-alba and A. gombiformis can be considered of greater nutritional value than the highly fibrous and low digestible grasses (S. pungens, L. spartum and S. tenacissima) that should be considered emergency roughages
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    Effect of polyethylene glycol addition on methane production from some Algerian browse plant species in an in vitro gas system
    (om.ciheam.org, 2013) Lyas Bouazza; sohil Boufennara
    Abstract. Biological activity of tannins of different browse plants was measured as the change in methane production when plant material was incubated with and without polyethylene glycol (PEG) using the in vitro gas production technique. Four dicotyledon browse plants (Atriplex halimus, Artemisia campestris, Artemisia herba-alba, Calobota saharae) and three monocotyledon browse plants (Stipagrostis pungens, Lygeum spartum and Stipa tenacissima), collected from an arid zone in Bousâada were evaluated. The increase in gas production upon the addition of PEG, compared with that without PEG, for the browse species varied widely (P<0.05), being particularly high in S. tenacissima (+35.0%) and low in L. spartum (+1.5%). The methane concentration in fermentation gas ranged from 7.9% with A. halimus to 18.6% with L. spartum. The higher increase in methane percentage was noted for S. tenacissima (+47.4%) and the lower percent value was observed for L. spartum (+1.5%). In presence of PEG, the methane production had positive correlation with crude protein (r = +0.78) while in absence of PEG, the methane production was correlated negatively with total condensed tannins (r = -0.88). The strongest correlation (r = 0.89; P<0.01) was between total condensed tannins and methane increase response to the addition of polyethylene glycol, suggesting that tannin compounds appeared to be useful to identify plants possessing antimethanogenic activity
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    Methane production from the rumen fermentation of Algerian Acacia tree foliage
    (om.ciheam.org, 2014) Lyas Bouazza; sohil Boufennara
    Abstract. The present study was carried out to determine the in vitro methane production from the rumen fermentation of Acacia tree leaves (Acacia nilotica, A. cyanophylla, A. albida, A. horrida and Albizia julibrissin) and its reduction by the addition of a tannin-blocking agent (polyethylene glycol, PEG). Gas production was determined when foliage from the five plant species was incubated in diluted rumen fluid for 6, 12, 24 and 48 h, and methane was measured after the incubation at 24 h. The incubations were conducted either without or with the addition of the tannin binder polyethylene glycol (PEG-6000). This has been considered a bioassay of tannin activity, represented by the increase in gas (methane) production upon the addition of PEG (i.e., when tanning are neutralized). The ratio +PEG/-PEG (in total gas production) was highest for A. nilotica (2.23 and 1.75 at 12 h and 24h), followed by A. cyanophylla (1.73 at 48 h), reflecting the high amount and biologi - cal activity of tannins in these plants. PEG addition increased methane production for all the Acacia species, thus confirming that tannins in these samples affected methanogenesis. An increase in total volatile fatty acid concentration in samples with addition of PEG was observed only with A. nilotica and A. cyanophylla. Tannins contained in these plants could be of interest to reduce methane production, providing that other parameters of ruminal fermentation were not inhibited.
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    Nutritive evaluation of foliage from fodder trees and shrubs characteristic of Algerian arid and semi-arid areas
    (Journal of Animal and Feed Sciences, 2012-09-14) sohil Boufennara; Lyas Bouazza
    ABSTRACT The chemical composition and digestibility of foliage from nine browse plant species (Artemisia herba-alba, Atriplex halimus, Acacia nilotica, Acacia horrida, Acacia saligna, Faidherbia albida, Albizia julibrissin, Vicia faba and Punica granatum) grown in arid and semi-arid areas of Algeria were evaluated. Feed components were determined by proximate analysis, whereas phenolic and tannin compounds were analysed by colorimetric procedures and their activity tested using a biological assay. Digestibility was assessed by conventional gravimetric in vitro and in situ methods, and rumen fermentation kinetics were estimated from the in vitro gas production technique. The foliage from Acacia species was found to be a protein-rich fodder for ruminants, although the high lignin and tannin content of some species is an important constraint limiting its digestive utilization in the gastrointestinal tract. The leguminous fodder tree, A. julibrissin, has a high protein content and its foliage is highly digestible owing to its low tannin content. Foliage from P. granatum is a highly digestible browse for ruminants.