RESEARCHERS from Central Queensland University have completed the first round of studies on feeding methane reducing feed additives through water.

The university compared 13 different products in lab studies testing their solubility, stability and whether the methane reducing properties stayed in-tact. The well-known seaweed asparagopsis and Bovaer were not part of the study.

Agolin, Beeocitrix+, Choline Chloride, Monensin Sodium Salt, Nitrates, Polygain, Saponin, SilvaFeed and Tartaric Acid were the other products involved in the study.

The study noted that most methane-reducing compounds to date have been developed and tested in dairy or feedlot applications, yet most of the global cattle population is grass-fed. The objective of the study was to identify methane-reducing compounds that could be delivered via drinking water, which is more applicable to most global livestock farming systems.

“The clear standout compounds in terms of methane reduction were sodium monensin and the Rumin8 IVP,” the paper said.

Of the two standout products, Rumin8 was found to have reduced methane production by 99pc in the lab conditions. Rumin8 is a synthetic tribromomethane (bromoform), which is the active ingredient in other seaweed based additive, has been progressing through a series of studies in feedlots and for grassfed beef production like the CQU study.

Rumin8 chief executive officer David Messina said the CQU trial results were consistent with the trial results from other lab and animal studies. He said the positive dry matter digestibility was also important for productivity case for the feed additives.

“This trial indicated almost total methane elimination in a laboratory setting, which was really pleasing for Rumin8,” Mr Messina said.

“The zero impact on dry matter digestibility is broadly consistent with the positive animal productivity results Rumin8 is achieving in animal trials globally.”

The paper said that the other standout, Monensin, had shown similar results in another study using lucerne – indicating that the product is likely to be inhibiting microbes producing hydrogen, which reduces the availability of hydrogen for methane production.

“The current use of monensin in the cattle industry as an ionophoric antibiotic and improver of feed conversion efficiency make it a promising candidate for deployment in water.

“Despite this, a meta-analysis of in vivo (animal) studies indicated that monensin only reduced methane by 10.7pc in beef steers. Furthermore, the difficulty in dissolving it into water would necessitate the development of a pre-made product where the monensin is already dissolved.”

Nitrates had shown bigger reductions in methane than monensin, however, it also had some challenges.

“The resulting decrease in methane production for Na and K nitrates in the current study appear consistent with other in vitro results, with methane reductions ranging from 55.1–76.1pc,” the study said.

“However, an in vivo study by Tomkins et all reported marginal effects of nitrates on enteric methane production, and that the risk of nitrate toxicity was also a major factor. Nitrate in excess can lead to the development of Methemoglobinemia due to the intermediate nitrite forming a strong bond with haemoglobin, which affects oxygen transportation in the blood.”

More work to be done on water medication

The study said more research was needed to determine the feasibility of using the additives through drinking water.

“Whilst the delivery of MRCs (methane reducing compounds) in cattle drinking water may be feasible, there are still several challenges that would need to be addressed before sustainable deployment could be achieved on-farm,” he said.

“There are existing technologies capable of delivering supplements to animal drinking water that could also deliver.

“Long-term solubility and stability studies on the MRCs being delivered in this fashion would need to be conducted to ensure minimal human interventions are required in remote locations. At the time of writing, the costs per animal for doses of MRCs are also quite high, and in lieu of a rebate scheme or a lowering of these costs through economies of scale, this may be a barrier to entry for many producers.”

• To read the full study click here.

Source: Rumin8/CQU