BACKGROUND
Information about the nutritive value, dry matter (DM) digestibility, and methane (CH4) emission potential of grass species is required for their optimal utilization in ruminant rations. The present study was designed: (i) to quantify the nutrient profile, mineral composition and in vitro dry matter digestibility (IVDMD) of winter grass species commonly available in northern Pakistan; and (ii) to measure the in vitro gas production (IVGP) and CH4 emission of the grass species during 72 h in vitro ruminal fermentation. Seven grass species, namely, Cenchrus ciliaris, Setaria anceps, Panicum antidotale, P. maximum, Pennisetum purpureum, Pennisetum orientale, and Atriplex lentiformis were assessed.
RESULTS
A high level of variability (P < 0.001) was observed among grass species for the content of all measured nutrients, IVDMD, IVGP, and CH4‐production. Notably, the content (g kg−1 DM) of crude protein varied from 59.8 to 143.3, neutral detergent fiber from 560.3 to 717.9, IVDMD from 375.1 to 576.2, and 72 h cumulative IVGP from 97.6 to 227.4 mL g−1 organic matter (OM) and CH4 from 48 to 67 mL g−1 OM. Among the grasses, P. antidotale had greater content (g kg−1 DM) of crude protein (CP) (143.3), IVDMD (576.2), and 72 h cumulative IVGP (227.4 mL g−1 OM), and produced the smallest amount of total CH4 (48 mL g−1 OM) during 72 h fermentation. In contrast, A. lentiformis had the lowest content (g kg−1 DM) of CP (59.8), IVDMD (375.1), 72 h cumulative IVGP (97.6 mL g−1 OM), and produced a greater amount of total CH4 (67 mL g−1 OM) during 72 h fermentation.
CONCLUSION
The findings of the current study highlight that it is possible to select and further develop grass species with high nutritional value and lower CH4‐production, which can improve livestock productivity, farm profitability, and long‐term environment sustainability. © 2020 Society of Chemical Industry
