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Can you capture methane to reduce feed costs?

Chris Church for Progressive Dairy Published on 12 June 2020

The first Canadian national dairy survey was conducted in 2015. Not surprisingly, producers from every region listed feed costs as a concern for their operation. Yet there is an older technology to improve return over feed (ROF) only used by 50% of Canadian producers.

In the U.S., 85% of dairies (and 95% of all feedyards) use this compound, so why are many dairies here missing out?



In 1965, agriculture was asking some of the same questions we ask today: “How can we make cows more efficient to feed an exploding population?” Elanco challenged their scientists to come up with practical solutions, and over the next 15 years they left no stones unturned.

The researchers focused on the magic of the rumen. We can feed grain to any species and produce glucose, but only ruminants can capture energy from forages. Could they improve on this process? This was an age before genetic modification, so searching for a naturally occurring fix seemed most logical. They began by making a “desktop” rumen to measure the changes in energy released by feed from different compounds. Then they scoured the world for samples to test – plants from South America, soil from Asia. Almost 100,000 specimens were tested during the 15 years.

During the testing, a soil sample from Arizona was found that had a bacteria later called Streptomyces cinnamonosis. It produces a compound that smells like cinnamon. And that compound had a profound effect in the rumen. Called monensin sodium (originally Rumensin), the compound changes the population of rumen bugs to select for energy efficiency.

When a cow consumes corn, the rumen bacteria convert the glucose into propionate. This is a readily usable substrate for energy, with no waste into the environment. If she eats forage, the glucose released is changed into acetate and butyrate. These can be later changed to glucose, but each loses some of their initial energy as methane. We have now learned this is an environmental worry, but it is also something you have paid to grow being lost to the air. Monensin has antimicrobial properties – it eliminates some of the bacteria that produce acetate and butyrate to promote more captured energy. This results in less methane and more energy for the cow.

Is monensin an antibiotic?

Monensin does have antimicrobial properties, but it has a very limited range of action. The World Health Organization ranks antibiotics on how important each is for human medicine (Class 1 through 4). The Class 1 are considered very important and should not be used as first-choice treatments (ceftiofurs). Monensin is considered a Class 4 – not important for human use. This allows use without a prescription (except in Quebec). The molecule is also effective at killing coccidia and reducing bloat.


How does it work on an ‘average’ dairy?

Monensin sodium is very well researched, with more than 1,000 papers in publication. In 2008, Dr. Todd Duffield from the University of Guelph summarized the outcomes from the dairy studies available. He started with 161 studies and was able to use the most complete trials from 59 (77 sites). The most consistent outcomes were more milk (+2.3%) and more protein yield (+1.9%) on less dry matter (-2.3%). The cow can produce more with less.

What about butterfat?

In the mid-’90s, some producers noticed that if they lowered their butterfat percentage, they could ship more protein as percent of the same quota, resulting in higher payments. One method used to accomplish this involved monensin. During Duffield’s summary, he found that lowered butterfat yield was not affected on average. There was a subpopulation of farms that had a decrease, but only if they were feeding high levels of unsaturated fats (Palm fat is safe.) This was especially notable in herds at the time that did not use TMR-based rations. Modern nutritionists are well trained at balancing rations for monensin and butterfat, and this should no longer be a concern. Some studies have even found a significant increase in butterfat percentage with modern feeding methods (+5.5%).

What would the expected Canadian return look like?

I know what you may be thinking: “A few percent change in the ration won’t affect my bottom line very much.” This may be true, but luckily the cost of monensin is very low (average $0.03 per cow per day). The Western Milk Pool and P5 use different pricing formulas, so each must be calculated separately. Figures 1 and 2 are calculated using the data from Duffield’s research.

P5 monensin return on investment

Western Milk Pool monenisin return on investment

As knowledge of feeding has changed over the last 10 years, we often see a slight increase in butterfat yield. Figures 3 and 4 detail that scenario.


P5 economics with stable butterfat

Western Milk Pool exonomics with stable butterfat

Controlled research is the gold standard, but I find many producers also like to know how a given product or process works for other local dairies. Many mills are now collecting local ROF financial results for their clients. Talk to your nutrition team about how ROF results stack up for herds feeding monensin compared to those that don’t.

Is monensin in the feed the same as in the bolus?

The same monensin molecule is found in the feed premix and the Kexxtone bolus, but the bolus works differently in the cow. Transition cows are at a higher risk of energy-related diseases, so feeding monensin makes logical sense. The challenge is: These cows eat inconsistently, making the dose of medicine fluctuate. The bolus places the molecule directly in the rumen, reducing the impact of intakes. The bolus (originally called Rumensin CRC) has been proven to reduce subclinical and clinical ketosis (50%), displaced abomasum (40%) and Johne’s disease bacterial shedding (73%). It delivers monensin for 95 days.

But what about the rest of the year?

The bolus is targeted for transition health conditions, and monensin is targeted at milk production efficiency. What if you want both outcomes? If given at close-up (three weeks precalving), the bolus pays out by 74 days in milk (DIM). Researchers studied the combination of using both monensin for the whole lactation at the same time as using a bolus. They focused on the safety, rather than any extra benefits. It was found that this is perfectly safe up to 16 parts per million of premix in the ration. This level is registered with the CFIA, so no prescription is required outside of Quebec.

Is there an opportunity in your herd?

As expenses continue to increase, dairy producers need to assess their ration costs carefully. Are you losing income by feeding unnecessary additives? Or are you losing revenue by forgoing proven additives and “throwing out the baby with the bath water?” end mark

References omitted but are available upon request. Click here to email an editor.

Chris Church
  • Chris Church

  • Technical Consultant
  • Elanco Animal Health
  • Email Chris Church