The aim of this study was to determine the chemical composition and in vitro digestibility, and to estimate the in vitro fermentation parameters of palm leaves and pedicels from Ghars palm variety. A rumen in situ technique was also used to examine In vitro Digestible Dry Matter (IDDM), In vitro Digestible Crude Protein (IDCP), and In vitro Digestible Neutral Fiber (IDNF), and rate and extent of gas production. Vetch-oat hay was taken as a reference feed material. The samples were collected in Tolga district (southeast Algeria). The Crude Protein (CP) content of the plant species was low for pedicels and palm leaves (33 and 60 g kg−1 DM, respectively). The highest content of total extractable phenols, tannins and condensed tannins was observed in palm leaves whereas pedicels showed lower concentrations. In vitro digestibility and in situ DM disappearance were slightly different for the examined forages. Analogue trends were observed for the in vitro fermentation kinetics estimated from the gas production curves. Pedicels showed the highest DM effective degradability (ED; assuming a passage rate of 0.03 h-1) whereas palm leaves seemed to be a poorly degradable material with an ED coefficient of 0.39 and 0.14 g g-1DM, respectively. Despite the moderate CP and high fiber content along with in vitro digestibility and in situ DM disappearance found in pedicels, in comparison with vetch oat hay degradation, it indicated that this plant could have a greater nutritional value. Dry matter disappearance after 144 h of incubation was negatively correlated with phenolic compounds and total extractable tannins, suggesting that the in vitro techniques can be appropriate for detecting the presence of anti-nutritional substances in shrubs. تفاصيل المقالة

The objective of the study was to evaluate the nutritional value of some native plants, collected from Algerian arid zones by in vitro gas production method. The volatile fatty acids (VFA) of samples were also determined in the culture medium. This work was carried out in 2011 and was conducted in comparison to a control substrate (oat vetch) considered as a reference plant in literature. The selected plants were collected in the arid areas of the Algerian desert. Nine forages including six dicotyledon plants (Atriplex halimus L., Artemisia campestris L., Artemisia herba-alba subsp. valentina, Astragalus gombiformis Pomel, Spartidium saharae (Coss. & Dur.) and Retama raetam Forssk., and three monocotyledon plants (Stipagrostis pungens (Desf.), Lygeum spartum L.and Stipa tenacissima L.) were selected. A. campestris, A. gombiformis and A. herba-alba recorded the highest values of gas production. The total VFA production of the different substrates is significantly different between them (p<0.0001). A. gombiformis had the highest total VFA (34.7 mmol/L) followed by A. campestris (32.8 mmol/L), while the lowest total production of VFA was observed in S. tenacissima (17.3 mmol/L). Generally, the plant studied can be classified in two groups, one group with poor-quality grasses (L. spartum. and S. tenacissima) and other with higher digestibility (A. gombiformis and Artemisia spp.). In conclusion, dicot species are therefore recommended for feeding ruminants. تفاصيل المقالة