Intra‐cultivar potential of Desmanthus spp. as a greenhouse gas mitigation strategy for tropical livestock pastoral systems

Improved agricultural efficiency and reduction in the impacts of tropical livestock farming on habitat degradation require global approaches that enhance ruminant farming functionality in terms of feed use efficiency, emissions and food security. This study evaluated the in vitro mitigation potential of the prostrate to erect, herbaceous Desmanthus spp. pasture legume adapted to semiarid clay soil land types in northern Australia. D. bicornutus, D. leptophyllus and D.virgatus were seasonally harvested from commercial plots by Agrimix Pty. Ltd. Samples of the legumes and the control Rhodes grass (Chloris gayana) using ruminal fluid from grazing Brahman (Bos indicus) steers were incubated in vitro (Ankom RF1 Technology) for 24, 48 and 72 h. Overall, the in vitro organic matter degradability (OMD) and methane production between Desmanthus species differed (P < 0.001). Compared to the control (0.656 ± 0.027 proportion of total OM) at 48 h of incubation, D. leptophyllus showed lower OMD (0.479 ± 0.016), while D. bicornutus (0.688 ± 0.016) and D. virgatus (0.619 ± 0.015) were different from each other, but similar to the control. Methane production (ml/g OM) was 15.7 ± 1.54, 3.7 ± 0.89, 12.0 ± 0.95 and 11.7 ± 0.95, respectively. It is suggested that the impact of these attributes may benefit household farmers in developing economies to expand productivity, improve livelihoods and meet the growing food consumption. Further analyses of the intra‐cultivar characteristics of Desmanthus spp. will complement the design of sustainable and efficient interventions across tropical pastoral feeding systems, with a particular emphasis on large‐scale grazing operations