PSXI-17 Influence of hops on in vitro ruminal fermentation of corn grain

Abstract An in vitro incubation was carried out to evaluate the potential of hops (Humulus lupulus) as an alternative to antibiotics for upgrading animal production. Whole pellets of hops (Variety Galena) were ground and incubated in a batch culture of ruminal fluid (2000 mg of ground corn grain + 10 mL of fresh rumen liquor). Ruminal fluid was collected from two beef cows through an esophageal tube. The hops were incubated by 24 h at levels of 0, 800, 1600 and 2400 µg/mL. Data were analyzed statistically by analysis of variance using PROC GLM of SAS. Hops addition linearly decreased (P < 0.01) gas production (GP; 90.89, 61.73, 36.63 and 28.37 µmol/g respectively) and methane production (MP; 9.76, 1.70, 1.30 and 0.46 µmol/g respectively). The CO2 production linearly increased as levels of hops increased (P < 0.02; 87.5, 88.4, 98.1 and 99.3 µmol/g respectively). The ammonia-N production was reduced in treatment 2 with respect to other treatments (P < 0.03; 12.6, 9.2, 13.7 and 13.5 µmol/g). Effects on ruminal fermentation of corn grain were dose dependent of hops. Addition of hops in ruminant feeding may offer a means to decrease ruminal methane production. Further research is needed to test efficacy of hops on other in vivo rumen-fermentation parameters.