Feed Additives

Feed additives can reduce costs, and that's good news.

Elevated feed costs may be the tallest hurdle that beef producers face in achieving greater profitability. Low supplies of hay, grains, and co-products have forced respective prices to climb to record-highs. For producers who plan to supplement cows this winter, feed additives, such as monensin, will help reduce feed costs.


Monensin, commonly referred to by its brand name, Rumensin, is an ionophore which targets gram-positive bacteria in the rumen. By reducing the gram-positive bacteria, the gram-negative bacteria are allowed to thrive. This leads to a shift in volatile fatty acids in the rumen in the favor of propionate, which is more efficiently used by cattle.

Feed efficiency

This translates into an increase in feed efficiency of 10%. This increase is seen when fed at the recommended level of 200 milligrams per head per day. A 10% increase in feed efficiency is easily explained by a cow needing 10% less feed to achieve the same gain or maintenance of gain.

Reproductive maturity

Research has also identified that adding monensin to a heifer development ration can result in a higher percentage of heifers being sexually mature at time of breeding. This likely has to do with the feed additive aiding in proper weight gain prior to breeding. Developing and breeding heifers can be challenging at times. Monensin may allow producers to utilize some poorer quality feeds without sacrificing weight gain and onset of puberty. Heifers that are sexually mature tend to have higher first-service conception rates.

Adding monensin is a good practice for producers every year, but when feed costs are elevated the cost savings is magnified. A producer can ask the local feed mill to incorporate Rumensin into a supplement or mix it with the current ration. The cost of adding this ionophore is likely 2-3 cents per head per day, well worth the feed savings. Caution should be taken when feeding around horses; monensin can be fatal to equine.


Aspergillis oryzae extract

Another feed additive that could aid in reducing costs would be an Aspergillis oryzae extract, or commonly known as Amaferm.

  • Amaferm is a direct fed microbial that aids in breaking lignin bonds from cellulose and hemicellulose.
  • Lignin bonds act as shields to digestion. Thus, with more lignin bonds broken, more efficient digestion can occur.

This results in an increase of 10% in forage utilization and promotes an environment favorable to more digesting bacteria. It should be fed to cows at 2-3 grams per head per day. This will result in a cost of 4-6 cents per head per day. Amaferm can be added into a mixed ration, top-dressed, or a mineral.

Lignin is more prevalent in poor quality, mature forages. Poor quality forages like cornstalks and CRP hay are being relied upon to stretch low hay inventories. Look into these feed additives to stretch your feeds and save you money.

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