Methane inhibitors include chemical compounds that block methanogens, the microbes in the rumen of grazing animals like cows and sheep, from producing methane. These inhibitors can be delivered as feed additives or slow-release boluses. There are also other emerging technologies such as vaccination, wearables and novel breeding strategies.

SPCA is concerned these technologies may have unintended effects on gut health, nutrient absorption, behaviour, or long-term welfare, particularly if used at scale without thorough oversight. On the other hand, monitoring the use of dietary inhibitors may find that they can effectively reduce emissions without negatively affecting animal welfare, or even improve welfare, which could address consumer concerns around the use of inhibitors as they become more widespread.

SPCA is concerned that the absence of regulation for the development, diversification and application of methane inhibitor technologies may put animal welfare at risk. We recommend that animal welfare impact assessments are mandated for any new methane inhibitors, for example under the Agricultural Compounds and Veterinary Medicines (ACVM) Act. SPCA also calls for surveillance, including animal welfare impact reporting, to be conducted where inhibitors are used.