Meat and Methane

The message about methane ('marsh gas') seems to be spreading. Increasing numbers of people are now aware that methane is a 'greenhouse gas'. They also know that, although it is relatively short-lived in the atmosphere, it is 30 times more potent than carbon dioxide. The public have also been increasingly reminded cattle belches are a major source of methane. Beef producers are becoming concerned about the impact of this negative public relations on their 'product'. A number of lines of investigation, all attempting to reduce methane emissions from cows, are now being explored (https://www.theguardian.com/environment/2021/sep/30/cow-methane-emissions-reduce-seaweed-kowbucha ). A hypoxic (without oxygen) fermentation process is initiated in the rumen of cows (part of the animal's digestive system), by methanogen bacteria. This process, enables cows to break down the cellulose cell walls of the plant material on which they feed. The methane (usually burped by the cow) is a byproduct of this process. One way of reducing methane production by cows is to block enzyme acivity used by the methanogens. Bovaer, is a commercial feed, containing 3 nitrooxypropanol. This feed is readily accepted by cattle, where it reduces methane emissions by an average of 30%. The cow's feed can also be mixed with material from Asparagopsis seaweeds. These seaweeds (which are now being 'farmed' in Hawaii and elsewhere), contain bromoform. Bromoform also blocks enzymatic activity in methanogens, lowering methane emissions by circa 80%. Neither Bovaer nor the seaweed additive appear to change the taste of the meat. There are, however, some unanswered questions in the case of the seaweed's other chemicals on the cows. Scientists are also exploring developing a vaccine against the methanogen bacteria, to neutralise their actions. Others, are attempting to develop breeds of cow with low methane emissions. These low-emission breeds might well have lowered rumen populations of methanogens. There is, however, an obvious question. Will a cow with reduced methane production be as efficient in its use of plant food? The breaking of cellulose must be useful to herbivores, as a) glucose can be extracted from cellulose and b) breaking the cell walls, facilitates access to their internal content. Finally, a very different approach is being taken by a company (Zelp) who have developed a mask for cows. The mask can, reportedly catch and neutralise 50% of the belched methane. Of course, by far the easiest way of reducing methane emissions from cattle, would be to reduce their numbers. Unfortunately, this solution is unlikely to appeal to cattle barons and many of their more carnivorous customers.