Comparing Mineral and Chemical Compounds, in Vitro Gas Production and Fermentation Parameters of some Range Species in Torbat-e Jam, Iran

Plants growable in rangelands play an important role in the feeding of ruminants; hence, the nutritive value of four plants (Falcaria vulgaris, Malva neglecta, Chenopodium album, and Polygonum aviculare) was determined by different laboratory methods. The plant samples were randomly collected in vegetative phase from different rangelands of Torbat-e Jam, Iran in spring 2018. The range of dry matter (125 to 184 g/kg), neutral detergent fiber (252 to 358 g/kgDM), acid detergent fiber (155 to 258 g/kgDM), crude protein (172 to 275 g/kgDM), ether extract (9 to 41 g/kgDM), crude fiber (135 to 185 g/kgDM), ash (140 to 252 g/kgDM), acid detergent lignin (41 to 123 g/kgDM), nitrogen-free extract (300 to 496 g/kgDM), and non-fiber carbohydrates (183 to 356 g/kgDM) were different between the studied plants. The mineral composition was also different between treatments and they were containing reasonable minerals as compared to some other plants commonly used as forage feed. The highest in vitro organic matter digestibility (OMD: 876 g/kgDM) and in vitro dry matter digestibility (DMD: 828 g/kgDM) were observed in Polygonum aviculare. The other fermentation parameters (NH3-N, total volatile fatty acids: TVFA, and pH) were also different among the plant species when incubated in the laboratory medium. There was a strong positive correlation between 24 h gas production with OMD, DMD and TVFA and negative correlation between 24 h gas production with crude protein, NH3-N and ether extract. The results showed that each of the four studied plants can be considered as a potential source of feedstuff for the alleviation of problems associated with lack of forage in Iran. According to these reported data, it seems that the nutritional value of Falcaria vulgaris and Polygonum aviculare is higher than the other two plants.