Plasma Metabolites, Productive Performance and Rumen Volatile Fatty Acid Profiles of Northern Australian Bos indicus Steers Supplemented with Desmanthus and Lucerne

The hypothesis tested was that tropical steers supplemented with the Desmanthus legume and lucerne, a widely characterized temperate of high nutritive value, would elicit similar responses in plasma metabolite profiles, productive performance, nitrogen retention, volatile fatty acids (VFA). tannin-binding compound, polyethylene glycol-4000 (PEG), added to diets (160 g/kg dry matter) objective further exploring (N) utilization animals relative lucerne. From February June 2020, sixteen yearling Brangus (average liveweight 232 ± 6 kg) were fed background diet Rhodes grass (Chloris gayana) hay for 28 days, before introducing three cultivars (Desmanthus virgatus cv. JCU2, D. bicornutus JCU4, leptophyllus JCU7) lucerne (Medicago sativa) at 30% matter intake (DMI). Relative backgrounding period, all exhibited growth performance. Steers recorded lower DMI animal but higher fecal N concentration than Among cultivars, there no significant differences concentrations, VFA, profiles. addition PEG induced rumen iso-acid concentrations excretion. However, feeding spp. Bos indicus could be valuable means increasing utilization, which is attributable presence tannins, and, consequently, improve Since supplementation resulted liveweight, daily gains, overall performance supplementing Desmanthus, both supplements will does not hold must rejected. Further vivo investigation needed better understand impact tannins on utilization.