While it may seem impractical to either graze cattle in coastal bays or send train-loads of red seaweed across the country to cattle feedlots, the good news here is that the seaweed doesn’t have to completely replace grass or grain to have the beneficial effect. In tests performed at Australia’s national science agency CSIRO, feeding cows a diet that included just 0.2% red seaweed reduced methane production by 98%. Since the average cow eats about 55 pounds of food per day on a dry basis, this means their intake of the red macroalgae would be only about a tenth of a pound, making the amount of the red seaweed required seem remarkably possible.
It does this while actually helping cattle to use their other food more efficiently because it helps to optimize the process by which bacteria ferment grain and grass. So the cattle gain weight faster while producing less gas.
And there’s a secondary benefit: Raising the seaweed itself might also be good for both the air and the water. CSIRO has worked out methods where, done properly, growing red seaweed can itself help to sequester additional carbon and help reduce ocean acidification.
All of this makes red seaweed a big improvement over other proposed supplements, which reduce methane by only 20-40% while requiring that the supplement be a much higher percentage of the cattle’s diet. Or, in the case of Pennsylvania State research, requires feeding cattle a chemical supplement.
Jesus: Hey, Dad? God: Yes, Son? Jesus: Western civilization followed me home. Can I keep it? God: Certainly not! And put it down this minute--you don't know where it's been! Tom Robbins in Another Roadside Attraction