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Pack on the Pounds with Supplements

Cattle on pasture. There is something iconic, almost romantic, about a herd of cattle spread across a lush, green pasture with the wind dancing through the grass. Grazing cattle is the foundation of the cattle industry, the heart and soul, steeped in tradition. Many producers take advantage of placing growing or stocker cattle on pasture; each adding their own spin on the age-old tradition.

Lush spring and early summer pastures provide cattle with a mixture of energy, protein and some vitamins and minerals. The nutrients provided can be enough to get by, but seasonal forage and quality, and variability in soil type and moisture conditions, may not provide consistency in nutrients that your cattle need to perform at their absolute best. Below are two points to consider as you get ready to turn your cattle out on pasture; two simple investments that will provide the best returns.


When cattle are on green pasture, supplements, beyond salt, tend to be left out. The thought being that green grass will meet all their needs. Grazing cattle are most likely to be deficient in phosphorus, which can negatively affect growth and development of young cattle, as well as negatively impact reproductive efficacy.

Research conducted in Oklahoma with steers on rye pasture showed an improvement in average daily gains at 0.19 pounds per head per day, and total gain of 16 pounds, when salt was replaced with a complete mineral supplement (including salt and vitamins, individual results may vary). What is driving this? When we only provide salt, the cattle, and rumen bugs, are missing out on other nutrients they need to maximize efficiency and growth. These include calcium, phosphorus, copper, zinc, manganese, selenium, and vitamin E.

As we move through the summer, and the grass is either mature or starting to go dormant, producers may consider adding protein to their supplement as well. When forage protein is low, the rumen bugs aren’t as efficient as they are when protein is high. Adding a protein supplement, even at a low level, can increase rumen efficiency. This means better and more complete forage fermentation, increase volatile fatty acid (energy) production, and increase microbial protein production (protein source for the animal) for improved weight gain.


The addition of an ionophore (such as Bovatec® or Rumensin®) to a complete supplement can multiply the increase in efficiency gained switching from plain salt to a complete mineral supplement. Ionophores work by shifting the microbial population so that the net effect is increased production of propionic acid.

Here’s the science behind why it’s a good thing: When cattle are on high fiber, lower quality diets – without a supplement or ionophore – a large amount of acetic acid, a low energy yielding volatile fatty acid, is produced. Propionic acid is a higher energy yielding volatile fatty acid when compared to acetic acid. The increase in the production of propionic acid means a more efficient rumen. The improved rumen efficiency translates to improved performance by faster gains in your cattle with the same amount of forage.

To demonstrate the benefits of complete supplements, with and without an ionophore, research with backgrounding heifers was conducted in Alabama and Mississippi. In the Alabama study, the control group was only offered salt; in the Mississippi study, the control group was offered a trace mineral supplement without Bovatec®. The experimental groups in both studies received a low moisture block (LMB) with Bovatec® and free choice salt. The heifers receiving the LMB with Bovatec® outgained the control groups in both studies by 0.45 to 1 pound per head per day.

Dollars and cents

I’m sure you’re thinking, “that’s really nice, but what does it mean?’” It means your cattle are growing faster on the same amount of forage. If you are developing heifers, they will reach puberty faster and have the potential to cycle and breed sooner. If you’re going to be selling cattle, they will weigh more at the sale barn – meaning more dollars in your pocket. Table 1 has the results from the study conducted in Mississippi. It shows that for a little investment, you can more than make it back in cattle performance with greater profitability.

Wrap It Up

It’s hard to make an argument for not adding a complete trace mineral supplement to your pasture programs. Something as simple as making the change from plain salt (the colored salt blocks aren’t really adding much to the party) to a complete trace mineral supplement will improve gains on pasture. When you add an ionophore to the mix, you are bumping up efficiency again, adding extra pounds without having to increase available forage. Investing just a little more on a complete supplement, along with an ionophore, will provide you the greatest returns when it comes time to sell.

Bovatec® is a registered trademark of Zoetis

Rumensin® is a registered trademark of Elanco