In vitro gas and volatile fatty acids productions of some plants species collected from Algerian arid rangelands

The main objective of the study is evaluating the nutritional value of some browse plants collected from Algerian arid zones by determining the in vitro gas production at different incubation times and volatile fatty acids (VFA) production. This work 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 Algerian desert. Nine forages have been selected for this research work: six dicotyledon plants (Atriplex halimus, Artemisia campestris, Artemisia herba-alba, Astragalus gombiformis, Spartidium saharae and Retama raetam) and three monocotyledon plants (Stipagrostis pungens, Lygeum spartum and Stipa tenacissima). It has been found that A. campestris, A. gombiformis and A. herba-alba are the plants most fermented by the ruminal microbiota, until the time 36 hours of incubation time. A. gombiformis has the highest total VFA (34.7 mmol/L) while the lowest production of VFA is observed in S. tenacissima (17.3 mmol/L). The results obtained in this study clustered the studied species in two groups according to their nutritive value (considering jointly all the measures of gas production and volatiles fatty acids): one including the poor-quality grasses and another one including the most digestible dicot species (A. gombiformis and Artemisia spp.).