Submitted to: Western Section of Animal Science Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/20/2001
Publication Date: 6/1/2001
Citation: Interpretive Summary: Methane is a gas produced in the stomach (rumen) of animals like cows and sheep. The production of methane is an inefficient process because it is an energy source that cannot be used by the animal. We conducted experiments to determine if certain compounds could be used to decrease methane production in cows. All of the compounds we tested decreased methane production more than products currently being used by the livestock industry, and none of these compounds caused bad effects on digestion. This research will lead to the development of new and improved methods to reduce methane production by cows and sheep thus reducing costs producers have to pay to feed their cattle. The ultimate beneficiaries of this research will be consumers who will not have to pay as much for beef and lamb products.
Technical Abstract: Ruminal methane (CH4) production is an inefficient process that results in losses of 2 to 12% of gross energy intake. Presently, we tested the effect of three potential inhibitors of ruminal CH4 production in vitro. Ruminal fluid collected from a cow maintained on an alfalfa: corn diet (1:1) was incubated (39 deg C) for 24 h under 100% CO2 in closed tubes (10 ml/tube) supplemented with 72 mM sodium formate and 12 mM 2-nitropropanol, nitroethane or nitroethanol (experiment 1) and with 12 or 24 mM nitroethane (experiment 2). Control cultures contained no added nitrocompound. Methane production was reduced (P < 0.05) from control incubations (27.6 +/- 2.1 and 17.7 +/- 1.1 umol/ml; mean +/- SE from n=3 for experiments 1 and 2, respectively) by more than 10-fold by all nitrocompounds. By comparison, CH4 production is typically reduced by about 33% when cattle are fed the widely used feed additive, monensin. In experiment 1, concentrations of acetate, propionate and butyrate produced by nitrocompound supplemented cultures were not significantly reduced (P>0.05) compared to those produced by control cultures. In experiment 2, a nitroethane effect (P < 0.05) on the production of acetate, propionate and total volatile fatty acids was observed, due to increases in amounts produced. Hydrogen did accumulate slightly in cultures supplemented with the nitrocompounds (values ranging from 0.4 to 2.8 umol/ml) thus suggesting that energetic efficiencies associated with microbial interspecies-H2 transfer were not optimized. Future research in this area may lead to the development of strategies that reduce economic costs associated with ruminal CH4 production.